Authorship：Last author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：American Chemical Society (ACS)  

DOI： 10.1021/acs.macromol.3c01049

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Authorship：Last author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Wiley  

Abstract

The regulation of cell behavior is crucial for understanding many fundamental biological processes and designing novel medical devices. Nano/micropatterning has been developed as a means of controlling cellular properties and behaviors. Using cinnamoyl groups that have undergone photodimerization, we have prepared facile photopatterning films with adjustable surface properties for cell patterning via simple steps. Our strategy for controlling surface properties uses the decrease in free volume induced by photocrosslinking. This paper describes the surface‐patterning properties of photocrosslinkable polymer films and the cell adhesion to their micropatterned surfaces. Upon culturing cells on micropatterned surfaces, preferential cell adhesion, alignment and proliferation are observed in the unexposed regions. Additionally, diverse surface patterns of photocrosslinkable polymer films have been fabricated using various photomasks, enabling effective control of cell adhesion and alignment. The ability to regulate cellular behavior via microfabricated surfaces of photocrosslinkable polymer films enables a new and facile approach for designing scaffolds for the development of novel advanced materials, tissue engineering, and regenerative medicine.

DOI： 10.1002/rpm.20230007

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Authorship：Last author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Royal Society of Chemistry (RSC)  

DLS measurements revealed that temperature-responsive gels prepared by ATRP have more homogeneous networks than those by free radical polymerization. The standard deviation of the scattered intensity is used to quantify the network inhomogeneity.

DOI： 10.1039/d3sm00044c

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Royal Society of Chemistry (RSC)  

Thermoresponsive hydrogels with a controlled drug binding capacity were designed to create drug reservoirs capable of both inhibiting drug leakage below the transition temperature and accelerating drug release above it.

DOI： 10.1039/d2tb00325b

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：American Chemical Society (ACS)  

DOI： 10.1021/acsami.2c00592

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：MDPI AG  

Standard hydrogels prepared by free radical polymerization (FRP) have heterogeneous structures with a wide mesh size distribution, which affect their mechanical and separation properties. Recent research has identified four-armed poly(ethylene glycol) (tetra-PEG) as a solution to this problem. tetra-PEG gels with a homogeneous network can be prepared and applied as high-strength gels and cell-culture substrates by reacting two types of tetra-PEG with different reactive groups at the ends. In this study, we report a photoresponsive tetra-PEG that undergoes a phase transition from a sol to a gel state in response to light. tetra-PEGs containing cinnamoyl and maleimide groups at the ends of the four-armed chains were found to gel when exposed to light. The effects of polymer concentration and light irradiation time on the gelation of tetra-PEG containing photodimerization groups were investigated. The results showed that the elastic modulus of the gel increased with the increase in the light irradiation time.

DOI： 10.3390/gels8030183

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Wiley  

Photoresponsive polymers, whose structures or properties change when exposed to ultraviolet (UV) light, have been studied for the fabrication of micro- and nano-devices for various applications. Herein, photoresponsive polymer films are investigated with directly micropatternable surfaces formed by only UV exposure without the development process using solvents. The photoresponsive polymer films are designed based on the decrease in free volume induced by the photodimerization of cinnamoyl groups. The photoresponsive polymers are synthesized by copolymerizing a monomer with photodimerizable groups and a poly(dimethylsiloxane) macromonomer. Micropatterns are easily formed on the film surfaces by only UV exposure using photomasks. The micropatterns are achieved due to the decrease in the film thickness with a decrease in the free volume induced by photo-crosslinking. Using a decrease in free volume by photo-crosslinking leads to wide practical applications with simple processes and low costs.

DOI： 10.1002/admi.202101965

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Other Link： https://onlinelibrary.wiley.com/doi/full-xml/10.1002/admi.202101965

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Royal Society of Chemistry (RSC)  

Photoresponsive zwitterionic polymer particles that undergo photo-assembling by ultraviolet light irradiation are designed as smart nanomaterials with the bioinert surface.

DOI： 10.1039/d1tb02342j

PubMed

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Royal Society of Chemistry (RSC)  

The temperature-responsive core–shell microgels comprising PMPC core and side-chain oligo(ethylene glycol) polymer shell were prepared via inverse miniemulsion RAFT polymerization using a water-soluble emulsifier with RAFT agent terminus.

DOI： 10.1039/d2py00425a

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Authorship：Last author,　Corresponding author   Publishing type：Research paper (scientific journal)   Publisher：American Chemical Society (ACS)  

DOI： 10.1021/acs.langmuir.1c01677

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Publishing type：Research paper (scientific journal)   Publisher：American Chemical Society (ACS)  

DOI： 10.1021/acsapm.1c00592

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

<title>Abstract</title>Hydrogels are flexible materials that have high potential for use in various applications due to their unique properties. However, their applications are greatly restricted by the low mechanical performance caused by high water content and inhomogeneous networks. This paper reports a universal strategy for easily preparing hydrogels that are tough and stretchable without any special structures or complicated processes. Our strategy involves tuning the polymerization conditions to form networks with many polymer chain entanglements to achieve energy dissipation. Tough and stretchable hydrogels can be prepared by free radical polymerization with a high monomer concentration and low cross-linker content to optimize the balance between physical and chemical cross-links by entanglements and covalent bonds, respectively. The strategy of using polymer chain entanglements for energy dissipation allows us to overcome the limitation of low mechanical performance, which leads to the wide practical use of hydrogels.

DOI： 10.1038/s41427-021-00302-2

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Other Link： http://www.nature.com/articles/s41427-021-00302-2

Authorship：Last author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)  

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1021/acs.langmuir.8b01608

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Nature Publishing Group  

The water content of thermo-responsive hydrogels can be drastically altered by small changes in temperature because their polymer chains change from hydrophilic to hydrophobic above their low critical solution temperature (LCST). In general, such smart hydrogels have been utilized in aqueous solutions or in their wet state, and no attempt has been made to determine the phase-transition behavior of the gels in their dried states. Here we demonstrate an application of the thermo-responsive behavior of an interpenetrating polymer network (IPN) gel comprising thermo-responsive poly(N-isopropylacrylamide) and hydrophilic sodium alginate networks in their dried states. The dried IPN gel absorbs considerable moisture from air at temperatures below its LCST and oozes the absorbed moisture as liquid water above its LCST. These phenomena provide energy exchange systems in which moisture from air can be condensed to liquid water using the controllable hydrophilic/hydrophobic properties of thermo-responsive gels with a small temperature change.

DOI： 10.1038/s41467-018-04810-8

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Institute of Physics Publishing  

Diagnosis sensors using micro-total analysis systems (μ-TAS) have been developed for detecting target biomolecules such as proteins and saccharides because they are signal biomolecules for monitoring body conditions and diseases. In this study, biomolecularly stimuli-responsive micro-sized hydrogels that exhibited quick shrinkage in response to lectin concanavalinA (ConA) were prepared in a microchannel by photopolymerization using a fluorescence microscope. In preparing the micro-size hydrogels, glycosyloxyethyl methacrylate (GEMA) as a ligand monomer was copolymerized with a crosslinker in the presence of template ConA in molecular imprinting. The ConA-imprinted micro-hydrogel showed greater shrinkage in response to target ConA than nonimprinted micro-hydrogel. When a buffer solution was switched to an aqueous ConA solution in the Y-shaped microchannel, the flow rates changed quickly because of the responsive shrinkage of the micro-hydrogel prepared in the microchannel. These results suggest that the ConA-imprinted micro-hydrogel acted as a self-regulated microvalve in microfluidic systems.

DOI： 10.1088/1361-6439/aaa876

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

Stimuli-responsive polymers that undergo a sol-gel transition in response to changes in environmental factors such as pH and temperature have attracted considerable attention for biomedical applications such as drug reservoirs for controlled release and scaffolds for tissue engineering. Although numerous stimuli-responsive polymers that undergo a sol-gel transition have been reported, the literature contains few accounts of biomolecularly stimuli-responsive polymers that undergo a sol-gel transition in response to a specific biomolecule. In previous studies, we designed biomolecule-responsive hydrogels that undergo changes in volume in response to a target biomolecule; the strategy involves using biomolecular complexes as dynamic cross-links in the gel networks. In the present study, we designed biotin-conjugated four-armed poly(ethylene glycol) (biotinylated Tetra-PEG) as biomolecular stimuli-responsive sol-gel transition polymers that underwent the phase transition from a sol to a gel state in response to avidin as a target biomolecule. When avidin that forms a biomolecular complex with biotin was added to a buffer solution containing biotinylated Tetra-PEG, the solution transformed to a gel state immediately. However, the addition of a buffer solution with free biotin to the resulting hydrogel induced its dissociation to a sol state. The sol-gel transition of a buffer solution with biotinylated Tetra-PEG was directly affected by polymer concentration and the biotin/avidin molar ratio. The phase diagram of the sol-gel transition of biotinylated Tetra-PEG in a buffer solution as a function of polymer concentration and the biotin/avidin molar ratio is presented.

DOI： 10.1039/c7py01370a

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

Temperature-responsive poly(N-isopropylacrylamide) (PNIPAAm) gels were prepared via atom transfer radical polymerization (ATRP), and their mechanical and responsive properties were investigated from the viewpoint of their network homogeneity. When the PNIPAAm gels were prepared by ATRP and free radical polymerization (FRP) at a low temperature, no difference was observed in the mechanical properties. However, the PNIPAAm gels prepared via ATRP at room temperature showed a higher elastic modulus and greater temperature-responsive change than the gels prepared via FRP. The temperature-responsive shrinkage rate of the PNIPAAm gel prepared via ATRP was slower than that of the gel prepared via FRP. Dynamic light scattering (DLS) measurements revealed that these results can be attributed to the more homogeneous network structure in the PNIPAAm gel prepared via ATRP than in the gel prepared via FRP.

DOI： 10.1039/c7py01323j

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Polypeptides have inherent secondary structures, such as alpha-helix,) beta-sheet, and random coil structures, depending on their amino acid sequence. beta-Cyclodextrins (CDs) as ligands of molecular recognition sites were introduced into poly(Llysine) (PLL), which undergoes a structural transition in response to a pH change. CD-introduced PLL (CD-PLL) hydrogels with dynamic molecular recognition sites for bisphenol A (BPA) were strategically designed by molecular imprinting, where BPA was used as a template molecule with a minute amount of cross-linkers. The resulting BPA-imprinted CD-PLL hydrogels with a random coil structure underwent a change in volume in response to the target BPA because the ligand CDs formed a complex with BPA. Additionally, a change in pH induced a structural transition of the CD-PLL chains from the random coil to an a-helix, followed by a conformational change of the molecular recognition sites within the BPA-imprinted CD-PLL hydrogels. As a result, BPA adsorption into the BPA-imprinted CD-PLL hydrogels strongly depended on pH. The molecular recognition ability of the BPA-imprinted CD-PLL hydrogels was controlled by the helix coil transition of the PLL chains. BPA, as a model drug, was loaded within the CD-PLL hydrogel networks by molecular imprinting, and the BPA template was not extracted from the hydrogel networks. The drug release from the drug-loaded CD-PLL hydrogel was regulated by the pH-responsive structural transition of the PLL chains, which could control the stability of the inclusion complex between the drugs and CD ligands. The fascinating properties of the BPA-imprinted CD-PLL hydrogels with dynamic molecular recognition sites suggest that they exhibit potential as suitable drug carriers inspired from the allosteric effects of proteins.

DOI： 10.1021/acs.macromol.6b02688

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

This paper focuses on the addition of hydrophobic ionic liquid, 1-allyl-3-butylimidazilium bis (trifluoromethane sulfonyl) imide ([ABIM]TFSI) to poly(methyl methacrylate)-graft-poly(dimethylsiloxane) (PMMA-g-PDMS) membranes, on the pervaporation characteristics for the removal of dilute benzene from an aqueous solution. When an aqueous solution of 0.05 wt% benzene was permeated through [ABIM]TFSI/PMMA-g-PDMS membranes, they showed high benzene permselectivity and permeability. Both the benzene/water selectivity and permeability of the membranes were enhanced with an increase of [ABIM]TFSI, because the affinities of [ABIM]TFSI/PMMA-g-PDMS membranes for benzene were increased by introducing [ABIM]TFSI into the membranes. The [ABIM]TFSI localized in the PMMA layer of the microphase separated PMMA-g-PDMS membrane plays an important role as an absorbent to selectively partition benzene from the aqueous benzene solution. (C) 2016 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.memsci.2016.01.057

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

This paper describes the removal of volatile organic compounds (VOCs) such as chloroform, benzene and toluene from aqueous solutions of dilute VOCs using the poly(styrene)-b-poly(dimethylsiloxane) (PSt-bPDMS) membranes containing an ionic liquid, 1-allyl-3-butylimidazilium bis (trifluoromethane sulfonyl) imide ([ABIM]TFSI) ([ABIM]TFSI/PSt-b-PDMS) by pervaporation. When aqueous solutions of 0.05 wt% VOCs were permeated through [ABIM]TFSI/PSt-b-PDMS membranes, they showed strong VOC/water selectivity. Both the permeability and the VOC permselectivity of [ABIM]TFSI/PSt-b-PDMS membranes were enhanced by increasing the [ABIM]TFSI content, because the affinity of [ABIM]TFSI/PSt-b-PDMS membranes for VOCs was increased by introducing [ABIM]TFSI into the membranes. The [ABIM]TFSI is localized in the PSt-b-PDMS membrane plays an important role as an absorbent to selectively partition VOCs from the aqueous solution. (C) 2016 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.memsci.2016.01.031

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：NATURE PUBLISHING GROUP  

Molecular imprinting is a well-known fabrication technique for designing artificial receptors and molecular sensors. The technique resembles a lock and key mechanism and utilizes shape-complementary cavities within polymeric materials as molecular recognition sites for various relevant molecules. In this study, we prepared molecularly imprinted polypeptide gel layers based on cyclodextrin-modified poly(L-lysine) (CD-PLL) on quartz crystal microbalance (QCM) sensor chips and investigated their molecular recognition behaviors for bisphenol A (BPA) using the QCM technique. With BPA as the template and CD as its ligand, the BPA-imprinted CD-PLL gel layers were prepared on electropolymerized polyterthiophene films, which were formed using electrochemical QCM (EQCM). The BPA-imprinted CD-PLL gel layer chip exhibited a much greater QCM response than the non-imprinted gel layer chip in an aqueous BPA solution. The greater response of the BPA-imprinted CD-PLL gel layer chip means that molecular imprinting enabled CD ligands to be arranged at optimal positions for forming molecular recognition sites. The combination of in situ electropolymerization using EQCM and molecular imprinting provides useful methods for fabricating highly selective and sensitive sensor devices for monitoring minute amounts of BPA in water.

DOI： 10.1038/pj.2016.23

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Language：English   Publishing type：Part of collection (book)   Publisher：Elsevier Inc.  

Monitoring biological or biochemical processes is of utmost importance for medical and biological applications. Development of highly sensitive, specific, and cost-effective biosensors is in considerable demand because they lead to highly precise diagnosis and individualized medicine. This chapter provides an overview of widely used biosensors and biosensing techniques such as enzyme-based electrochemical biosensors, enzyme-linked immunosorbent assay, quantitative polymerase chain reaction, and DNA microarray. These are widely utilized diagnostic tools and methods for exploring biomarkers in medical and biological fields. In addition, important research into the development of biosensors by utilizing surface plasmon resonance sensors, field-effect transistors, and gold nanoparticles is also described in this chapter. This representative research will contribute to the realization of next-generation medical systems such as individualized medicine and ultrasensitive point-of-care detection of biomarkers.

DOI： 10.1016/B978-0-323-37127-8.00010-8

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DOI： 10.1515/molim-2016-0003

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

A novel azobenzene siloxane hybrid material displaying photoinduced macroscopic motions has been prepared by one-step organosilane self-assembly. Two types of alkoxysilane precursors with either pendant or bridging azobenzene groups were synthesized via thiol-ene click reactions. Hybrid films with well-ordered lamellar structures were obtained by hydrolysis and polycondensation of these precursors. The film with solely pendant azobenzene groups showed reversible and rapid d-spacing variation upon UV-vis irradiation, which was induced by the trans-cis isomerization of azobenzene moieties. The flexible, free-standing film obtained by co-condensation of two types of precursors showed reversible bending unbending motions upon UV-vis irradiation. The partial cross-linking between the siloxane layers by bridging azobenzene groups was crucial for photoinduced distortion of the film. This film possesses high elastic modulus, good thermal stability, and shows large amplitude of photoinduced bending unbending over a wide temperature range. This is the first report on photoinduced macroscopic motions of azobenzene-containing siloxane-based materials. These materials possess great potential for applications in smart devices and energy conversion systems.

DOI： 10.1021/jacs.5b06172

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：CHEMICAL SOC JAPAN  

Poly(L-lysine) (PLL) undergoes structural change from alpha-helix to random coil in response to a change in pH in an aqueous solution. By chemical crosslinking of PLL with ethylene glycol diglycidyl ether (EGDE), we prepared pH-responsive hydrogels that undergo a change in volume and conformation between a-helix and random coil in response to a change in pH. The difference in transition pH between a PLL linear polymer and a PLL hydrogel revealed that chemical crosslinking stabilized the helical structure of PLL chains in hydrogel networks.

DOI： 10.1246/cl.150464

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCI LTD  

The permeation and separation characteristics of an ethanol/water azeotrope through chitosan membranes of different molecular weights and degrees of deacetylation during pervaporation were investigated. The normalized permeation rate decreased with increasing molecular weight up to 90 kDa, but at over 90 kDa, the rate increased. On the other hand, the water/ethanol selectivity increased with increasing molecular weight up to 90 kDa but decreased at over 90 kDa. With increasing degree of deacetylation, the water/ethanol permselectivity increased significantly, but the normalized permeation rate decreased. The characteristics of chitosan membranes are discussed based on their chemical and physical structures such as the contact angle, density, degree of swelling, and glass transition temperature. (C) 2014 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.carbpol.2014.11.032

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCI LTD  

The permeation and separation characteristics of an ethanol/water azeotrope through chitosan membranes of different molecular weights and degrees of deacetylation during pervaporation were investigated. The normalized permeation rate decreased with increasing molecular weight up to 90 kDa, but at over 90 kDa, the rate increased. On the other hand, the water/ethanol selectivity increased with increasing molecular weight up to 90 kDa but decreased at over 90 kDa. With increasing degree of deacetylation, the water/ethanol permselectivity increased significantly, but the normalized permeation rate decreased. The characteristics of chitosan membranes are discussed based on their chemical and physical structures such as the contact angle, density, degree of swelling, and glass transition temperature. (C) 2014 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.carbpol.2014.11.032

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

Microdevices designed for practical environmental pollution monitoring need to detect specific pollutants such as dioxins. Bisphenol A (BPA) has been widely used as a monomer for the synthesis of polycarbonate and epoxy resins. However, the recent discovery of its high potential ability to disrupt human endocrine systems has made the development of smart systems and microdevices for its detection and removal necessary. Molecule-responsive microsized hydrogels with -cycrodextrin (-CD) as ligands are prepared by photopolymerization using a fluorescence microscope. The molecule-responsive micro-hydrogels show ultra-quick shrinkage in response to target BPA. Furthermore, the flow rate of a microchannel is autonomously regulated by the molecule-responsive shrinking of their hydrogels as smart microvalves.

DOI： 10.1002/marc.201400676

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：NATURE PUBLISHING GROUP  

Novel organic-inorganic hybrid nanoparticles with a bisphenol A (BPA)-responsive hydrogel layer on the surface of SiO2 nanoparticles were prepared via surface-initiated atom transfer radical polymerization of acrylamide (AAm), acryloyl-modified beta-cyclodextrin (CD) and N, N'-methylenebisacrylamide. The resulting CD-PAAm/SiO2 nanoparticles underwent a change in size in response to BPA. The BPA-responsive shrinkage of the CD-PAAm/SiO2 nanoparticles was caused by an increase in the crosslinking density of the CD-PAAm hydrogel layer, which resulted from the formation of CD-BPA-CD complexes acting as dynamic crosslinks. The smart functions of BPA-responsive organic-inorganic hybrid nanoparticles can provide useful tools for constructing molecular sensors and adsorption materials.

DOI： 10.1038/pj.2014.122

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

DOI： 10.1021/cm503040u

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：CHEMICAL SOC JAPAN  

We prepared lectin-imprinted hydrogel layers on surface plasmon resonance (SPR) sensor chips by atom transfer radical polymerization (ATRP). In a buffer solution with a target protein, the SPR signal and binding constant of the lectin-imprinted hydrogel layer chip were much larger than those of the nonimprinted hydrogel layer chip prepared without using a template lectin. By molecular imprinting with ATRP, recognition sites for the target lectin were formed within thin hydrogel layers on the SPR sensor chips. The lectin-imprinted hydrogel layer chips with recognition sites for target protein are candidates for highly sensitive sensor devices for an SPR sensing system.

DOI： 10.1246/cl.140103

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

Target molecule-responsive hydrogels with beta-cyclodextrin (beta-CD) were prepared via molecular imprinting using bisphenol A (BPA) as a template. BPA-imprinted hydrogels showed greater shrinkage than non-imprinted hydrogels because CD ligands arranged at suitable positions formed CD-BPA-CD complexes that acted as crosslinks.

DOI： 10.1039/c4cc01187b

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：CHEMICAL SOC JAPAN  

We prepared antibody-immobilized gel layers on surface plasmon resonance (SPR) sensor chips by atom transfer radical polymerization (ATRP). In a buffer solution with a target antigen, the SPR signal of the antibody-immobilized gel layer chip with an optimal thickness was much larger than that of a directly antibody-immobilized chip prepared by the standard amine coupling method. The antibody-immobilized gel layer chips are candidates as highly sensitive bioconjugated devices for SPR sensing systems. This paper focuses on the relationship between the thickness of the gel layer and the SPR signal in the detection of a target antigen.

DOI： 10.1246/cl.2012.1660

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

Bioconjugated gel particles that have complexes composed of lectin concanavalin A (ConA) and 2-glucosyloxyethyl methacrylate (GEMA) were synthesized by the surfactant-free emulsion copolymerization of N,N-diethylaminoethyl methacrylate (DEAEMA), poly(ethylene glycol) dimethacrylate (PEGDMA). GEMA, and modified-ConA with polymerizable groups. The resultant gel particles having GEMA-ConA complexes (GEMA-ConA gel particles) were colloidally stable in a phosphate buffer solution and had a diameter of approximately 750 nm. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) measurements implied that GEMA-ConA gel particles have core-shell structures consisting of a hydrophobic core of DEAEMA and a hydrophilic shell of GEMA and PEGDMA containing ConA. GEMA-ConA gel particles underwent a change in size in response to glucose in a phosphate buffer solution. The swelling ratio of GEMA-ConA gel particles gradually increased with an increase in the glucose concentration. On the other hand, the swelling ratio of GEMA-ConA gel particles remained unchanged in a phosphate buffer solution containing galactose. The glucose-responsive swelling of GEMA-ConA gel particles was induced by the dissociation of GEMA-ConA complexes acting as reversible cross-links, because free glucose behaved as an inhibitor of GEMA-ConA complexes. These results indicate that GEMA-ConA gel particles can recognize glucose selectively and undergo changes in size in response to the glucose concentration. The smart functions of glucose-responsive gel particles can provide tools for constructing self-regulated drug delivery systems and sensor systems useful for treating diabetes. (C) 2011 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.colsurfb.2011.10.008

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

To improve conversion of n-butanol to the corresponding ester using acetic acid, the ionic liquid 1-allyl-3-butylimidazolium bis(trifluoromethanesulfonyl) imide ([ABIM]TFSI), which does not dissolve in the water by-product, and poly(vinyl alcohol) (PVA) or PVA-TEOS (tetraethoxysilane) hybrid membranes were employed when using evapomeation (EV), along with microwave heating. The effect on the conversion of n-butanol of each individual process variable as well as that of all of the variables used in combination was investigated, and the characteristics of each approach are discussed. (c) 2012 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.cattod.2012.03.020

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：NATURE PUBLISHING GROUP  

A novel nucleobase-terminated organosilane with nucleobase and ethoxysilane moieties was synthesized by a simple method in which bromouracil reacts with amino-terminated organosilane without solvents. The uracil-terminated organosilane was self-assembled on a hydroxylated surface, and then the uracil-concentrated surface was obtained. The resulting uracil-terminated self-assembled layers were characterized by X-ray photoelectron spectroscopy and ellipsometry. Adenine complementary to uracil was effectively adsorbed onto the resultant uracil-concentrated surface by multiple hydrogen bonds. Herein, a simple method is provided for synthesizing a nucleobase-terminated organosilane and modifying a hydroxylated surface to a nucleobase-concentrated surface. Our method, which uses the self-assembly of nucleobase-terminated organosilanes, facilitates the construction of bioconjugated devices for separating and sensing nucleobases and nucleic acids. Polymer Journal (2012) 44, 625-631; doi:10.1038/pj.2012.41; published online 28 March 2012

DOI： 10.1038/pj.2012.41

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-BLACKWELL  

Tumor-marker-imprinted hydrogels having lectin and antibody molecules as ligands for a tumor-specific marker glycoprotein were strategically prepared by biomolecular imprinting using minute amounts of low-molecular-weight or high-molecular-weight cross-linkers. The tumor-marker-imprinted hydrogels shrank gradually in response to a target glycoprotein, because their apparent cross-linking density increased owing to simultaneous complex formation of lectin and antibody ligands with a target glycoprotein after their ligands dynamically recognized the glycoprotein. The swelling ratio of the tumor-marker-imprinted hydrogel using high-molecular-weight cross-linker with an optimal chain length decreased more drastically than that using a low-molecular-weight cross-linker, but the hydrogel using the cross-linker with a chain that was too long did not exhibit tumor-marker responsive behavior. This paper focuses on the effect of the molecular weight of cross-linkers on the responsive behavior of tumor-marker-imprinted hydrogels having lectin and antibody molecules as ligands. The cross-linker chain length was an important factor in determining the dynamic glycoprotein recognition and responsive behavior of the biomolecule-imprinted hydrogels. Copyright (c) 2012 John Wiley & Sons, Ltd.

DOI： 10.1002/jmr.2190

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DOI： 10.4236/msa.2011.23021

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：BUDAPEST UNIV TECHNOL & ECON  

To control the swelling of sodium carboxymethylcellulose (CMCNa) membranes, mixtures of CMCNa and glutaraldehyde (GA) and mixtures of CMCNa as an organic component and tetraethoxysilane (TEOS) as an inorganic component were prepared, and CMCNa/GA cross-linked membranes and CMCNa/TEOS hybrid membranes were formed. In the separation of an ethanol/water azeotrope by pervaporation (PV), the effects of the GA or TEOS content on the water/ethanol selectivity and permeability of these CMCNa/GA cross-linked and CMCNa/TEOS hybrid membranes were investigated. Cross-linked and hybrid membranes containing up to 10 wt% GA or 10 wt% TEOS exhibited higher water/ethanol selectivity than CMCNa membrane without any cross-linker. This resulted from both increased density and depressed swelling of the membranes by the formation of a cross-linked structure. The relationship between the structure of the CMCNa/GA cross-linked membranes and CMCNa/TEOS hybrid membranes and their permeation and separation characteristics for an ethanol/water azeotrope during PV is discussed in detail.

DOI： 10.3144/expresspolymlett.2010.83

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：JOHN WILEY & SONS INC  

Stimuli-responsive bioconjugated hydrogels that can respond to a target antigen (antigen-responsive hydrogels) were prepared by introducing antigen-antibody bindings as reversible crosslinks into the gel networks. The preparation conditions of the antigen-responsive hydrogels and the mechanism of the antigen-responsive behavior were investigated, focusing on bioconjugated hydrogel structures. This article also focuses on the effect of semi-interpenetrating polymer network (semi-IPN) structures on the antigen-responsive swelling/shrinking behavior of bioconjugated hydrogels with antigen-antibody bindings. The preparation conditions and the network structures of the bioconjugated hydrogels are discussed in relation to designing antigen-responsive hydrogels. (C) 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 2144-2157, 2009

DOI： 10.1002/polb.21812

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

Growth and melting rates of a single crystal of ice in ammonium polyacrylate (NH(4)PA) aqueous solutions were measured at different solution temperatures, and the morphology of the ice crystals was observed. Thermal hysteresis, defined as the difference between the melting temperature and the non-equilibrium freezing temperature of ice, was confirmed in NH(4)PA solutions at concentrations below 25.0 mM. The higher the NH(4)PA concentration, the larger the thermal hysteresis, although the thermal hysteresis induced by NH(4)PA was much smaller than that induced by antifreeze proteins, antifreeze glycoproteins, or poly(vinyl alcohol). A single crystal of ice grown in the NH(4)PA solutions at temperatures within the thermal hysteresis region exhibited the basal faces. When the solution temperature was below the non-equilibrium freezing temperature, the ice crystal grew faster in the a-axis direction than in the c-axis direction, while retaining the basal faces. (C) 2008 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.jcrysgro.2008.04.011

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

To control the swelling of PVA membranes, mixtures of PVA and an inorganic oligosilane were prepared using sol-gel reactions to yield new PVA/oligosilane hybrid membranes. In the separation of an ethanol/water azeotropic mixture during pervaporation, the effect of the oligosilane content on the water/ethanol selectivity of PVA/oligosilane hybrid membranes was investigated. The water/ethanol selectivity of PVA/oligosilane hybrid membranes was higher than that of PVA membranes, but the water/ethanol selectivity of hybrid membranes decreased with increasing oligosilane content. In order to increase the water/ethanol selectivity, PVA/oligosilane hybrid membranes were annealed. The water/ethanol selectivity of annealed PVA/oligosilane hybrid. membranes was greater than annealed hybrid membranes, and significantly governed by the oligosilane content, which could be attributed to both sorption and diffusion selectivities. The relationship between the structure of un-annealed and annealed PVA/Oligosilane hybrid membranes along with permeation and separation characteristics of an ethanol/water azeotropic mixture during pervaporation are discussed in detail.

DOI： 10.1002/macp.200600531

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：JOHN WILEY & SONS INC  

We synthesized anionic hydrogels containing fluorophores and investigated the adsorption of a cationic quencher having an amino group into hydrogels by fluorescence resonance energy transfer (FRET). FRET from the fluorophore to the quencher in hydrogels was examined by fluorescence intensity and fluorescence decay using a fluorescence spectrophotometer and femtosecond laser spectroscopy. The fluorescence intensity of the fluorophore-containing hydrogels decreased rapidly with increasing amounts of adsorbed cationic quencher. The fluorescence emission of the fluorophore in the quencher- adsorbed hydrogels containing fluorophores decayed more rapidly than that of the original hydrogels. The aforementioned result indicates that the fluorescence of the fluorophorecontaining hydrogels is quenched due to FRET from the fluorophore to the quencher as the cationic quenchers can approach the fluorophores in hydrogels by electrostatic interactions. (c) 2006 Wiley Periodicals, Inc.

DOI： 10.1002/polb.20958

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

Two kinds of urease-immobilized polymer membranes were prepared. One was prepared by bulk-copolymerizing a mixture consisting of vinylized urease (VU), acrylamide (AAm), 2-hydroxylethylmethacrylate (HEMA) and a cross-linker (urease-immobilized poly(VU-AAm-HEMA) membrane) and another was prepared by ultrafiltrating a mixture composed of urease, quaternized chitosan and sodium carboxymethylcellulose in an aqueous sodium bromide solution (urease-immobilized polyion complex membrane). The permeation and hydrolytic characteristics of aqueous urea solutions were kinetically investigated under various conditions through urease-immobilized membranes. The hydrolysis of urea through urease-immobilized membranes followed Michaelis-Menten kinetics and is discussed herein. (c) 2006 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.cattod.2005.12.007

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：JOHN WILEY & SONS LTD  

Responsiveness of a poly(acrylamide) (PAAm) hydrogel having a semi-interpenetrating polymer network (semi-IPN) structure was compared with that of a PAAm normal-type hydrogel in acetone/water mixtures. The PAAm semi-IPN hydrogel shrank much more rapidly by changes in the acetone concentration than the PAAm normal-type hydrogel though there was no difference in their equilibrium swelling ratio between them. This suggests that the introduction of a semi-IPN structure into a hydrogel enhances its responsiveness very easily. Copyright (c) 2006 John Wiley & Sons, Ltd.

DOI： 10.1002/pat.818

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：JOHN WILEY & SONS INC  

The pervaporation (PV) performance of crosslinked poly(dimethylsiloxane) dimethylmethaerylate (PDMSDMMA) membranes for an aqueous solution of various hydrocarbons was studied using sorption-diffusion theory. Three chlorinated hydrocarbons (chloroform, trichloroethylene, and tetrachloromethane) and three aromatic hydrocarbons (benzene, chlorobenzene, and toluene) were used as the permeants. When aqueous solutions of 0.05 wt % hydrocarbon were permeated through the crosslinked PDMSDMMA membranes, they showed high hydrocarbon/water selectivity and permeability during PV. The hydrocarbon/water selectivity of the crosslinked PDMSDMMA membranes was significantly dependent upon the permeants; in particular, chloroform removed the hydrocarbons most efficiently in this study. The results of the temperature dependence of the PV performance and hydrocarbon absorption into the membrane revealed that the difference in hydrocarbon/water selectivity for various aqueous solutions of hydrocarbons during PV depended significantly on the molar volume and diameter of the hydrocarbons. The permeation and removal mechanism of hydrocarbons from water through crosslinked PDMSDMMA membranes can be explained by a qualitative model based on the diffusion jump model. (c) 2006 Wiley Periodicals, Inc.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

This paper focuses on the effects of the addition of fluorine-containing graft or block copolymer additives composed of 1H,1H,2H,2H-heptadecafluorodecyl acylate (perfluoroalkyl acylate, PFA) and poly(dimethylsiloxane) macromonomer (PDMS) or PDMS macro-azo-initiator to a microphase-separated membrane consisting of PDMS and poly(methyl methacrylate) (PMMA) on the benzene/water selectivity for an aqueous dilute benzene solution during pervaporation and the surface characteristics and structures of the surface- modified PMMA/PDMS membranes. The addition of the fluorine-containing copolymer additives, PFA-g-PDMS and PFA-b-PDMS, to a PMMA-g-PDMS membrane yielded hydrophobic surfaces at the air side of surface-modified membranes due to the localization of their additives on the air-side surface of these membranes. The addition of a small amount of the PFA-g-PDMS and PFA-b-PDMS enhanced both the benzene/water selectivity and the permeability for an aqueous dilute benzene solution during pervaporation because of the formation of their hydrophobic surfaces and the existence of the microphase-separated structures with a continuous PDMS phase in the inner of these membranes. When larger amounts of the PFA-g-PDMS and PFA-b-PDMS were added to a PMMA/PDMS, the latter additive could keep the microphase-separated structures with a continuous PDMS phase, but the former did not. The relationship between the permeation and separation characteristics for the removal of benzene from an aqueous benzene solution and the structures the PMMA-g-PDMS membranes surface-modified with PFA-g-PDMS and PFA-b-PDMS as fluorine-containing polymer additives is discussed in detail.

DOI： 10.1021/ma052302x

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：NATL ACAD SCIENCES  

We report dynamic glycoprotein recognition of gels prepared by biomolecular imprinting using lectin and antibody molecules as ligands for tumor-specific marker glycoproteins. The glycoprotein-imprinted gels prepared with minute amounts of cross-linkers could dynamically recognize tumor-specific marker glycoproteins by lectin and antibody ligands and induce volume changes according to the glycoprotein concentration. The glycoprotein-imprinted gel shrank in response to a target glycoprotein but nonimprinted gel swelled a little. The glycoprotein-responsive shrinking of the imprinted gel was caused by formation of lectin-glycoprotein-antibody complexes that acted as reversible cross-linking points. Glycoprotein-imprinted gels only shrank when both lectin and antibody in the gels simultaneously recognized the saccharide and peptide chains of the target glycoprotein. As shrinking behavior of biomolecularly imprinted gels in response to glycoproteins enables the accurate detection and recognition of tumor-specific marker glycoproteins, they have many potential applications as smart devices in sensing systems and for molecular diagnostics.

DOI： 10.1073/pnas.0506786103

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Language：Japanese   Publishing type：Research paper (international conference proceedings)  

In this study, we prepared two types of DNA-responsive gels that can swell or shrink in response to a target DNA. DNA-cross-linked gels were synthesized by introducing duplex DNAs as cross-linking points into a poly(acrylamide) (PAAm) gel. DNA-imprinted gels were prepared by molecular imprinting using single stranded DNAs as ligands for a target DNA. In a buffer solution containing a target DNA, the DNA-cross-linked gels swelled remarkably and the DNA-imprinted gels shrank gradually. The DNA-responsive swelling of the DNA-cross-linked gels was due to decreasing cross-linking density of the gels by complex exchange of a target DNA and a mismatch DNA. The DNA-responsive shrinking of the DNA-imprinted gels was attributed to increasing cross-linking density by formation of duplex DNAs. Furthermore, the DNA-responsive swelling and shrinking behavior of the DNA-cross-linked gels and DNA-imprinted gels were strongly dependent upon sequences of DNAs when the gels were immersed in a buffer solution containing DNAs with various sequences. Therefore, the DNA-responsive gels have many potential applications as smart biomaterials for recognizing single nucleotide polymorphisms (SNPs).

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Language：Japanese   Publishing type：Research paper (international conference proceedings)  

DNA-imprinted gels were prepared by molecular imprinting using two ligand ssDNAs for a target DNA. After 3'acryloyl- and 5'acryloyl-ssDNAs were hybridized with a target DNA as a template, they were copolymerized with acrylamide and N,N'-methylenebisacrylamide by redox copolymerization. Then the DNA-imprinted gels were obtained by removing the template DNA from the resultant networks. The nonimprinted gels were also prepared by the same way without the template DNA. The swelling behavior of the DNA-imprinted gels, nonimprinted gels and PAAm gel in response to the target DNA or its analogues was investigated to evaluate recognition ability of DNA-imprinted gels.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

This paper focuses on the addition of tert-butylcalix[4]arene (CA) to cross-linked poly(dimethylsiloxane) (PDMS) membranes derived from poly(dimethylsiloxane) di(methyl methacrylate) macromonomer (PDMSD MMA) and various divinyl cross-linker compounds, on the pervaporation characteristics for the removal of dilute benzene from an aqueous solution. When an aqueous solution of 0.05 wt.-% benzene was permeated through the crosslinked PDMSDMMA membranes containing CA they showed high benzene/water selectivity and permeability. Both the benzene/water selectivity and permeability of the membranes were enhanced by increasing both the divinyl compound cross-linker content and the amount of CA, and were significantly influenced by the type of divinyl compound. Addition of CA to PDMSDMMA membranes cross-linked with divinylperfluorohexane (DVF) showed the best pervaporation performance. The normalized permeation rate, benzene/water separation factor, and pervaporation separation index of these membranes were 1.86 x 10(-5) kg.m/(m(2).h), 5 027, and 9 350, respectively. The pervaporation characteristics of the cross-linked PDMSDMMA membranes containing CA were studied with respect to their chemical and physical structure. Furthermore, the mechanism of the selective permeation of benzene over water through these membranes was investigated.

DOI： 10.1002/macp.200500337

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Swelling of poly(vinyl alcohol-co-acrylic acid) (P(VA-co-AA)) membranes in aqueous alcohol solutions operated under pervaporation conditions leads to low water/ethanol selectivity. To reduce swelling, organic-inorganic hybrid membranes composed of P(VA-co-AA) and tetraethoxysilane (TEOS) were prepared. However, when an aqueous ethanol solution was permeated through the P(VA-co-AA)/ TEOS hybrid membranes by pervaporation, the permeation rate increased and the water/ethanol selectivity decreased with increasing TEOS content. The increase in the permeation rate and the decrease in the water/ethanol selectivity were caused by an increase in the degree of swelling of the membrane and a decrease in the membrane density with increasing TEOS content. These effects resulted from insufficient formation of hydrogen bonds between the silanol groups by hydrolysis of TEOS and the hydroxyl and carboxyl groups of P(VA-co-AA). When the P(VA-co-AA)/TEOS hybrid membranes were annealed, the water/ethanol separation factor increased with increasing annealing time and TEOS content. Longer annealing time promoted the dehydration-condensation reaction between P(VA-co-AA) and TEOS in P(VA-co-AA)/TEOS hybrid membranes, leading to enhanced water/ethanol selectivity of the hybrid membranes.

DOI： 10.1021/ma051450k

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

The permeation and separation characteristics of volatile organic compounds (VOCs), such as chloroform, benzene, and toluene, from water by pervaporation through cross-linked poly(dimethylsiloxane) membranes prepared from poly(dimethylsiloxane) dimethylmethacrylate macromonomer (PDMSDMMA) and divinyl compounds, such as ethylene glycol dimethylmethacrylate (EGDM), divinyl benzene (DVB), divinyl siloxane (DVS), and divinyl perfluoro-n-hexane (DVF) are described. When aqueous solutions containing 0.05 wt.% VOCs were permeated through cross-linked PDMSDMMA membranes, these membranes showed high VOC/water selectivity and permeability. Both VOC/water selectivity and permeability were affected significantly by the divinyl compound. Furthermore cross-linked PDMSDMMA membranes showed the highest chloroform/water selectivity. The VOC/water selectivity was mainly governed by the sorption selectivity rather than the diffusion selectivity. However, the difference in the selectivity between different types of VOCs depended on differences in the diffusivity of permeants. With increasing downstream pressure, the VOC/water selectivity of all cross-linked PDMSDMMA membranes increased, but the permeability decreased. A PDMSDMMA-DVF membrane exhibited a normalized permeation rate of 1.9 x 10(-5) kg m/m(2) It and a separation factor for chloroform/water of 4850, yielding a separation index of 9110. The pervaporation characteristics of the cross-linked PDMSDMMA membranes are discussed based on their chemical and physical structures as well as the chemical and physical properties of the permeants. (c) 2005 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.memsci.2005.03.027

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

The pervaporation performance of optimized poly(butylmetacrylate-co-vinyltriethoxysilane)/tetraethoxy- silane (P(BMA-co-VTES)/TEOS) hybrid membranes for the removal of benzene from water was investigated. P(BMA-co-VTES)/TEOS hybrid membranes prepared by the sol-gel reaction were modified by annealing and trimethylsilylation to enhance the performance of these membranes. The annealing and trimethylmethoxysilane (TMS)-modifications of P(BMA-co-VTES)/TEOS hybrid membranes gave more hydrophobic membranes compared with untreated P(BMA-co-VTES)/TEOS hybrid membranes and, consequently, the amount of benzene sorbed in the modified P(BMA-co-VTES)/TEOS hybrid membranes increased significantly. When an aqueous solution of dilute benzene was permeated by pervaporation through the annealed and TMS-modified P(BMA-co-VTES)/TEOS hybrid membranes, the annealing treatment enhanced the benzene/water selectivity significantly. This result was attributed to a decrease in residual silanol groups in the annealed hybrid membranes and the formation of an optimum cross-linked structure of the annealed P(BMA-co-VTES)/TEOS hybrid membranes.

DOI： 10.1002/macp.200500101

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

This paper focuses on the effects of fluorine cross-linker of the cross-linked poly(dimethylsiloxane) membranes from polydimethylsiloxane dimethylmethacrylate macromonomer (PDMSDMMA) and divinyl perfluoro-n-hexane (DVF) on the pervaporation characteristics of the removal of benzene from an aqueous solution of dilute benzene. When an aqueous solution of 0.05 wt% benzene was permeated through the cross-linked PDMSDMMA (PDMSDMMA-DVF) membranes, they showed a high benzene permselectivity and permeability of these membranes was enhanced with increasing DVF content significantly. The best normalized permeation rate, separation factor for benzene permselectivity, and pervaporation separation index (PSI) of a PDMSDMMA-DVF membrane were 1.72 x 10(-5) kg m/m(2) h, 4316, and 7423, respectively. The best normalized permeation rate of a PDMSDMMA-DVF membrane was approximately same as the PDMSDMMA membranes cross-linked with other divinyl compounds, but the separation factor and PSI of the former membrane were greater than those of the latter ones. These pervaporation characteristics are discussed from the viewpoint of chemical and physical structure of the cross-linked PDMSDMMA-DVF membranes in detail. &COPY; 2004 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.molstruc.2004.04.032

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

Cellulose alkyl esters such as ethyl, butyryl, pentyl, and heptyl cellulose with different numbers of carbon in the alkyl ester group were synthesized for the separation of a mixture of benzene/cyclohexane (Bz/Chx = 5/95 w/w) with a low concentration of benzene. All of cellulose alkyl ester membranes showed high benzene/cyclohexane selectivity for a Bz/Chx mixture in pervaporation. With increasing carbon number in the ester groups, the permeation rate increased but the benzene/cyclohexane selectivity decreased. The increase in the permeation rate could be attributed to an increase in the swelling of the membrane due to the feed mixture, and the decrease in the benzene/cyclohexane selectivity was dependent on both the decrease in the solubility selectivity and the diffusion selectivity. These pervaporation characteristics are discussed from the viewpoints of chemical and physical structure of the cellulose alkyl ester membranes such as the degree of swelling, the contact angle, and the density of the cellulose ester membranes, and the solution composition absorbed into their membranes.

DOI： 10.1002/macp.200400488

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

Preparation of organic-inorganic hybrid membranes and their pervaporation permeation and separation characteristics for an aqueous solution of 0.05 wt.-% benzene are described. In this study, we prepared organic-inorganic hybrid membranes by the sol-gel reaction of tetraethoxysilane (TEOS) as an inorganic component with poly(methyl methacrylate-co-vinyltriethoxysilane) (P(MMA-co-VTES)) and poly(butyl methacrylate-co-vinyltriethoxysilane) (P(BMA-co-VTES)) as organic components. When an aqueous solution of dilute benzene (0.05 wt.-%) was permeated through the P(MMA-co-VTES)/TEOS and 13(BMA-co-VTES)/TEOS hybrid membranes, the benzene concentration in the permeate through all hybrid membranes,vas higher than that in the feed solution. This result demonstrates that these hybrid membranes are benzene selective for an aqueous solution containing dilute benzene. The benzene/water selectivity of the P(BMA-coVTES)/TEOS hybrid membrane was about 20 times higher than that of the P(MMA-co-VTES)/TEOS hybrid membrane. Specifically, the P(BMA-co-VTES)/TEOS hybrid membrane with a TEOS content of 75 mol-% showed the highest benzene/water selectivity. The benzene/water selectivity of the hybrid membranes depended significantly on the cross-linked structures formed by the sol-gel reaction of VTES and TEOS.

DOI： 10.1002/macp.200400401

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Language：Japanese   Publishing type：Research paper (international conference proceedings)  

Sequence specific DNA-responsive gels were prepared by molecular imprinting using single strand DNA as ligands, which are complementary to target DNA. The DNA-imprinted gel shrank more remarkably in the presence of the target DNA than the nonimprinted gel, but the PAAm gel did not change. The DNA-responsive shrinking of the DNA-imprinted gel is attributed to hybridization between target DNA and DNA ligands. Moreover, the presence of only fullmatch target DNA induced shrinking of the DNA-imprinted gel, but that of one base mismatch DNAs did not Therefore, the DNA-imprinted gels have many potential applications as smart materials for constructing DNArecognition systems.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

To control swelling of quaternized chitosan (q-Chito) membranes, mixtures of q-Chito as an organic component and tetraethoxysilane (TEOS) as an inorganic component were prepared using the sol-gel reaction, and novel q-Chito/TEOS hybrid membranes were formed. In the separation of an ethanol/water azeotrope by pervaporation, the effect of TEOS content on the water/ethanol selectivity of q-Chito/TEOS hybrid membranes was investigated. Hybrid membranes containing up to 45 mol % TEOS exhibited higher water/ethanol selectivity than the q-Chito membrane. This resulted from depressed swelling of the membranes by formation of a cross-linked structure. However, introduction of excess TEOS led to greater swelling of the hybrid membranes. Therefore, the water/ethanol selectivity of the hybrid membranes containing more than 45 mol % TEOS was lower than that of the q-Chito membrane. The relationship between the structure of q-Chito/TEOS hybrid membranes and their permeation and separation characteristics during pervaporation of an ethanol/water azeotrope is discussed in detail.

DOI： 10.1021/bm0498880

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：VSP BV  

Glucose-responsive hydrogels were prepared by copolymerization of a monomer having a pendant glucose with modified lectin (concanavalin A (ConA)) having vinyl groups. Swelling behavior of ConA-copolymerized glucosyloxyethyl methacrylate (GEMA) hydrogels was discussed from the viewpoint of their synthetic condition and structures. The swelling ratio of the ConA-copolymerized GEMA hydrogels was strongly dependent on the glucose concentration in a buffer solution. As free glucose resulted in the dissociation of the complex between ConA and pendant glucose in the networks and the cross-linking density in the hydrogel decreased, the hydrogels swelled gradually in the presence of free glucose. Leak of ConA from the ConA-entrapment hydrogel and ConA-copolymerized hydrogel was examined in order to discuss the reversible changes of their glucose-responsive behavior. During swelling in the presence of free glucose, ConA leaked out of the ConA-entrapment GEMA hydrogel but did not out of the ConA-copolymerized GEMA hydrogel. As a result, the ConA-copolymerized GEMA hydrogel showed the reversible swelling changes in response to a stepwise change in the glucose concentration. This study revealed that covalent immobilization of ConA in the GEMA networks is very important for development of reversibly glucose-responsive hydrogels.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：VSP BV  

In order to prepare a polymer matrix capable of loading protein at high density. anionic hydrogels were synthesized by copolymerizing a monomer carrying a pendant phosphate group, methacryloyl-polyoxyethyl phosphate, with N-isopropylacrylamide and N,N'-methylane-bis-acrylamide, and the stumuli-sensitivity of hydrogels was characterized. The number of repeating ethylene glycol units in the phosphate carrying monomer was 1. 2. 5 or S. Lysozyme hearing a positive net charge was immobilized in the hydrogel through formation of Polyelectrolyle complex. 11 was shown that the amount of complexed lysozyme reached to 1.7 02 dry gel. when high content of a Phosphate-carrying monomer with 5 ethylene glycol units was incorporated into a hydrogel. It was,as further found that lysozyme complexed with phosphate-carrying network could be. released by immersion of the lysozyme/hydrogel composite in a phosphate buffer Solution of pH 7.4 owing to the pH-sensitivity, of the hydorgel but no lysozyme was released at pH 1.4. The initial rate of lysozyme release was varied depending on the length of the ethylene glycol chains possessed by a network polymer and the content of the phosphate-carrying monomer unit. Lysozyme released from the phosphate-cart)ring hydrogel was proved to retain enzymatic activity at a level similar to the activity of lysozyme. which had been kept in buffer solution.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

This paper focuses on the effects of cross-linkers of the cross-linked poly(dimethylsiloxane) membranes derived from poly(dimethylsiloxane) dimethyl methacrylate macromonomer (PDMSDMMA), and divinyl compound, on the pervaporation characteristics of the removal of benzene from an aqueous solution of dilute benzene. When an aqueous solution of 0.05 wt % benzene was permeated through the cross-linked PDMSDMMA membranes, they showed high benzene permselectivity. Both the permeability and benzene permselectivity of the membranes were enhanced with increasing divinyl compound content as the cross-linker and were significantly influenced by the kind of divinyl compound. PDMSDMMA membranes cross-linked with divinylsiloxane (DVS) showed very high membrane performance during pervaporation. The best normalized permeation rate, separation factor for benzene permselectivity, and pervaporation separation index of a PDMSDMMA-DVS membrane were 1.96 x 10(-5) in kg/(m(2) h), 2886, and 5657, respectively. These pervaporation characteristics are discussed from the viewpoint of the chemical and physical structure of the cross-linked PDMSDMMA membranes.

DOI： 10.1021/ma0345753

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

This paper focuses on the structural characteristics of membranes used in the removal of benzene from a dilute aqueous solution of benzene by pervaporation. Poly(methyl methacrylate)-graft-poly(dimethylsiloxane) (PMMA-g-PDMS) and poly(methyl methacrylate)-block-poly(dimethylsiloxane) (PMMA-b-PDMS) membranes containing tert-butylcalix[4]arene (CA), (CA/PMMA-g-PDMS and CA/ PMMA-b-PDMS) were studied. When an aqueous solution of 0.05 wt % benzene was permeated through CA/PMMA-g-PDMS and CA/PMMA-b-PDMS membranes, these membranes showed strong benzene permselectivity. Both the permeability and the benzene permselectivity of CA/PMAM-g-PDMS and CA/ PMMA-b-PDMS membranes were enhanced by increasing the CA content, due to the affinity of the CA for benzene. The permeability and the benzene permselectivity of CA/PMMA-b-PDMS membranes were much greater than those of CA/PMMA-g-PDMS membranes. Transmission electron microscope (TEM) observations revealed that both the CA/PMMA-g-PDMS and CA/PMMA-b-PDMS membranes had a microphase-separated structure consisting of a PMMA phase and a PDMS phase-containing CA. The microphase-separated structure of the latter membranes was much clearer than that of the former and was larnellar. The distribution of CA in the microphase-separated structure of the CA/PMMA-g-PDMS and CA/PMMA-b-PDMS membranes was analyzed by differential scanning calorimetry.

DOI： 10.1021/ma025863m

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

This study describes the dehydration of an ethanol/water azeotrope during evapomeation using polyion complex cross-linked chitosan composite (q-Chito-PEO acid polyion complex/PES composite) membranes, constructed from quaternized chitosan (q-Chito) and poly(ethylene oxydiglycolic acid) (PEO acid) on a porous poly(ether sulfone) (PES) support. Both the q-Chito/PES composite and the q-Chito-PEO acid polyion complex/PES composite membranes showed high water permselectivity for an ethanol/water azeotrope. Both the permeation rate and the water permselectivity of the q-Chito/PES composite membranes were enhanced by increasing, the degree of quaternization of the chitosan molecule because the affinity of the q-Chito/PES composite membranes for water was increased by introducing a quaternized ammonium group into the chitosan molecule. q-Chito-PEO acid polyion complex/PES composite membranes prepared from an equimolar ratio of carboxylate groups in the PEO acid versus quaternized ammonium groups in the q-Chito showed the maximum separation factor for water permselectivity without lowering the permeation rate. With an increasing molecular weight of PEO acid, the separation factor for water permselectivity increased, but the permeation rate almost did not change. The mechanism responsible for the separation of an ethanol/water azeotrope through the q-Chito-PEO acid polyion complex/PES composite membranes was analyzed by the solution-diffusion model. The permeation rate, separation factor for water permselectivity, and evapomeation index of q-Chito-PEO acid 400 polyion complex/PES composite membrane with an equimolar ratio of carboxylate groups in PEO acid 400 and ammonium groups in q-Chito were 3.5 x 10(-1) kg/(m(2) hr), 6300, and 2205, respectively, and very high membrane performance. The separation factor for water permselectivity for aqueous solutions of n-propyl and isopropyl alcohol was also maximized at an equimolar ratio of carboxylate groups and ammonium groups and was greater than that for an ethanol/water azeotrope. The above results were discussed from the viewpoint of the physical and chemical structure of the q-Chito-PEO acid polyion complex/PES composite membranes and the permeants.

DOI： 10.1021/bm025642o

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Publisher：The Society of Polymer Science, Japan  

DOI： 10.1295/kobunshi.52.476

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

To inhibit the swelling of PVA membranes in aqueous alcohol solutions, which leads to lowered water permselectivity during separation, organic-inorganic hybrid membranes composed of poly(vinyl alcohol) (PVA) and tetraethoxysilane (TEOS) were prepared. When an aqueous solution of 85 wt % ethanol was permeated through the PVA/TEOS hybrid membranes during pervaporation, the separation factor for water permselectivity increased, but the permeation rate decreased, with increasing TEOS content. We concluded that the decreased permeation rate was caused by decreasing the degree of swelling of the membrane. Therefore, this decrease in the degree of swelling and. the increase in membrane density were due to the formation of hydrogen bonds between the silanol groups resulting from the hydrolysis of TEOS and the hydroxyl group of PVA. When the PVA and PVA/TEOS hybrid membranes were annealed, the separation factor of these membranes increased with increasing annealing temperature and time. The fact that annealing at higher temperatures promoted the dehydration-condensation reaction between PVA and TEOS in PVA/TEOS membranes was related to the enhanced permselectivity of the PVA/TEOS membranes.

DOI： 10.1021/ma020850u

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Language：Japanese   Publisher：THE MEMBRANE SOCIETY OF JAPAN  

This paper describes the relationship between structures of multicomponent polymer membranes and their permselectivity for organic liquid mixtures in pervaporation. The morphology of microphase separation in the multicomponent polymer membranes containing poly (dimethylsiloxane) (PDMS) was quite different between block copolymer membranes and graft copolymer ones. The annealing of the block copolymer membranes resulted in dramatic changes in the morphology of their microphase separation, but that of the graft copolymer membranes did not. Their morphology strongly influenced the membrane permselectivity for organic liquid mixtures in pervaporation. This paper also focuses on simple surface modifications of membranes by polymer additives. Surface characteristics of polymer membranes were controlled by adding hydrophilic and hydrophobic copolymer additives. The permselectivity of the surface-modified membranes was improved without lowering their permeability by the simple surface modification. The addition of calixarene to microphase-separated membranes improved the permselectivity for volatile organic compounds in dilute aqueous solutions. Our results suggest a novel concept for designing the structure of multicomponent polymer membranes, that is, a method for controlling the permselectivity of pervaporation membranes.

DOI： 10.5360/membrane.27.188

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

The permeation and separation characteristics during evapomeation of an ethanol/water azeotrope (96.5 wt.-% ethanol) through quaternized chitosan (q-Chito) membranes and cross-linked with diethylene glycol diglycidyl ether (DEDGE), were studied. Both the q-Chito and the cross-linked q-Chito membranes showed high water-permselectivity for an ethanol/water azeotrope. The permeation rates for both membranes decreases and the water-permselectives increased, with an increasing degree for quaternization of the chitosan and cross-linker concentration. The mechanism of separation for the ethanol/water azeotrope through the q-Chito and cross q-Chito membranes was analyzed by the solution-diffusion model. Increasing permeation temperature increased the permeation rate the decreased the water-permselectivity for both membranes. However, the permeation rates of a cross-linked q-Chito membrane at 60-80degreesC were almost the same as those of the q-Chito membrane, and the separation factors for water-permselectivity (alpha(sepH2O/EtOH) = 4100-4200) in the former were greater by two orders of magnitude as compared to the latter (alpha(sepH2O/EtOH) = 47-58). The above results were discussed from the view points of the physical and chemical structure of the q-Chito and cross-linked q-Chito membranes.

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Language：English   Publisher：ELSEVIER SCIENCE BV  

Stimuli-sensitive hydrogels have attracted considerable attention as intelligent materials in the biochemical and biomedical fields, since they can sense environmental changes and induce structural changes by themselves. In particular, biomolecule-sensitive hydrogels that undergo swelling changes in response to specific biomolecules have become increasingly important because of their potential applications in the development of biomaterials and drug delivery systems. This article provides an over-view of the important and historical research regarding the synthesis and applications of glucose-sensitive hydrogels which exhibit swelling changes in response to glucose concentration. Enzymatically degradable hydrogels and antigen-sensitive hydrogels are also described in detail as protein-sensitive hydrogels that can respond to larger biomolecules. The synthetic strategies of other biomolecule-sensitive hydrogels are summarized on the basis of molecular imprinting and specific interaction. The biomolecule-sensitive hydrogels reviewed in this paper are expected to contribute significantly to the exploration and development of newer generations of intelligent biomaterials and self-regulated drug delivery systems. (C) 2002 Elsevier Science B.V. All rights reserved.

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Language：Japanese   Publisher：合成樹脂工業協会  

DOI： 10.11364/networkpolymer1996.23.Supplement_207

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Hydrophobically surface-modified membranes were prepared by adding a fluorine-containing graft copolymer into a microphase-separated membrane consisting of poly(dimethylsiloxane) (PDMS) and poly(methyl methacrylate) (PMMA). This study focuses on the effects of surface characteristics and microphase separation of the surface-modified membranes on their permselectivity for a dilute aqueous solution of benzene in pervaporation. Contact angle measurements and X-ray photoelectron spectroscopy revealed that the addition of a fluorine-containing copolymer produced a hydrophobic surface at the membrane air side due to its surface localization. It became apparent from transmission electron microscopy that adding a fluorine-containing copolymer of less than 1.2 wt % did not affect the morphology of the microphase-separated membrane, but adding the copolymer over 1.2 wt % resulted in a morphological change from a continuous PDMS phase to a discontinuous PDMS phase. The addition of a small amount of fluorine-containing copolymer into the microphase-separated membranes enhanced both the permeability and selectivity for a dilute aqueous solution of benzene in pervaporation because of their hydrophobic surfaces and microphase-separated structures. Specifically, the microphase-separated membrane containing 1.2 wt % of fluorine-containing copolymer concentrated from an aqueous solution of 0.05 wt % benzene to 70 wt % benzene and removed benzene in water very effectively. This paper also discusses the effect of the asymmetric surface structure of the hydrophobically surface-modified membranes on their permselectivity.

DOI： 10.1021/ma010707l

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

This paper describes the removal of benzene from an aqueous solution of dilute benzene using the poly(methyl methacrylate)-graft-poly(dimethylsiloxane) (PMMA-g-PDMS) membranes containing tert-butylcalix[4]arene (CA) (CA/PMMA-g-PDMS) by pervaporation. When an aqueous solution of 0.05 wt % benzene was permeated through the CA/PMMA-g-PDMS membranes, they showed strong benzene permselectivity. Both the permeability and the benzene permselectivity of the CAIPMNM-g-PDMS membranes were enhanced by increasing the CA content because the affinity of the CA/PMMA-g-PDMS membranes for benzene was increased by introducing CA into the membranes. Transmission electron microscope observations revealed that the CA/PMMA-g-PDMS membranes had a microphase-separated structure consisting of a PMMA phase and a PDMS phase containing CA. An examination of the permeation mechanism led us to the conclusion that the CA in the microphase-separated structure plays an important role as a carrier to selectively partition benzene from the aqueous solution.

DOI： 10.1021/ma010693j

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

Removal of volatile organic compounds (VOCs) such as benzene and chloroform in aqueous benzene and chloroform solutions through the poly(methylmethacrylate)-poly(dimethylsiloxane) (PMMA-g-PDMS), poly(ethylmethacrylate)-PDMS (PEMA-g-PDMS), and poly(n-butylmethacrylate)-PDMS (PBMA-g-PDMS) graft copolymer membranes was investigated by pervaporation. When aqueous solutions of dilute VOCs were permeated through the PMMA-R-PDMS and PEMA-g-PDMS membranes, these membranes showed a benzene- and chloroform-permselectivity. Permeation and separation characteristics of the PMMA-g-PDMS and PEMA-g-PDMS membranes changed drastically at a DMS content of about 40 and 70 mol%, respectively. Permeation rate and VOC-permselectivity of the PBMA-g-PDMS membrane, however, increased gradually with increasing DMS content, unlike those of the PMMA-g-PDMS and PEMA-g-PDMS membranes. Furthermore, the transmission electron microscope observations revealed that the PMMA-g-PDMS and PEMA-g-PDMS membranes had microphase separations consisting of a PDMS phase and a poly(alkylmethacrylate) phase, but the PBMA-g-PDMS membrane was homogeneous. The permeability and permselectivity for aqueous VOCs solutions through their graft copolymer membranes in pervaporation are discussed in detail from the viewpoint of their membrane structure, and permselectivity was analyzed by the solution-diffusion theory. (C) 2001 Elsevier Science B.V. All rights reserved.

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Language：Japanese   Publisher：Japan Thermosetting Plastics Industry Association  

In this paper, chitosan membranes cross-linked with diethyleneglycol diglycidylether (<I>DEDGE</I>) and glutaraldehyde (<I>GA</I>) for the recycle of water in urine were prepared. The characteristics of permeation and separation for an aqueous solution containing urine components through their cross-linked membranes in pervaporation were examined. The obtained cross-linked chitosan membranes permeated water more preferentially than NH<SUB>4</SUB><SUP>+</SUP>ion. The <I>DEDGE</I>-cross-linked chitosan membranes showed higher water-permselectivity than the <I>GA</I>-cross-linked chitosan ones. Furthermore, pervaporation characteristics of these membranes are also discussed in detail from the viewpoint of membrane structures.

DOI： 10.11364/networkpolymer1996.22.212

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：JOHN WILEY & SONS INC  

Over the past 18 years we have been deeply involved with the synthesis and applications of stimuli-responsive polymer systems, especially polymer-biomolecule conjugates. This article summarizes our work with one of these conjugate systems, specifically polymer-protein conjugates. We include conjugates prepared by random polymer conjugation to lysine amino groups, and also those prepared by site-specific conjugation of the polymer to specific amino acid sites that are genetically engineered into the known amino acid sequence of the protein. We describe the preparation and properties of thermally sensitive random conjugates to enzymes and several affinity recognition proteins. We have also prepared site-specific conjugates to streptavidin with temperature-sensitive polymers, pH-sensitive polymers, and light-sensitive polymers. The preparation of these conjugates and their many fascinating applications are reviewed in this article. (C) 2000 John Wiley & Sons, Inc.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：JOHN WILEY & SONS INC  

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Language：Japanese   Publisher：The Japan Society of Mechanical Engineers  

In order to make a precise experiment in vitro for simulating blood flow in vivo, we have been using high concentration suspension of alginic acid gel particles in various dispersion media as a model blood. In our early study it was clarified that this model blood obeyed Casson's diagram like actual blood, and it formed aggregation at low shear rate like actual red blood cell when it was dispersed in an aqueous solution of CaCl_2. In this study we investigated an elasticity of the model blood cell by a manipulator system. As a result, the followings were clarified; the model blood cell had residual deformation when the time duration that the particle was deformed was longer than about 1 min. We measured the force that deformed the particle by pushing the particle to the tip of the beam. As a result, we got a relationship between stress and deformation of the model blood cell. Moreover we found that force relaxation occurred when the stress was inflicted on the particle in long period.

DOI： 10.1299/jsmemecjo.2000.1.0_289

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Poly[1-(trimethylsilyl)-1-propyne] (PTMSP) membranes were surface-modified using polymer additives and their pervaporation properties for an aqueous ethanol solution were investigated. The polymer additives, PFA-g-PDMS and PMMA-g-PDMS, were synthesized by graft-co-polymerization of fluoroacrylate (PFA) and oligo dimethylsiloxane (DMS), and methylmethacrylate (MMA), respectively. The contact angle of water on the surface of the air-side of the surface-modified PTMSP membranes increased by the addition of PFA-g-PDMS and PMMA-g-PDMS. These results suggest that the surface-modified PTMSP membranes were more hydrophobic. Also, X-ray photoelectron spectroscopy (XPS) measurements supported that the polymer additives were concentrated at the surface of the air-side of the modified PTMSP membranes. The ethanol/water selectivity of the PTMSP membrane modified with PFA-g-PDMS increased significantly without a large decrease in flux compared with that of the PTMSP membrane. On the other hand, after modification of PTMSP with PMMA-g-PDMS both the flux and ethanol/water selectivity had a maximum at a certain amount Of PMMA-g-PDMS. The ethanol/water selectivity of the modified membrane was higher than that of the PTMSP membrane. High ethanol/water selectivity of the surface-modified PTMSP membranes depended on the solubility selectivity of the permeating species.

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Language：Japanese   Publisher：高分子刊行会  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Poly[1-(trimethylsilyl)-1-propyne] (PTMSP) membranes were surface-modified using polymer additives and their pervaporation properties for an aqueous ethanol solution were investigated. The polymer additives, PFA-g-PDMS and PMMA-g-PDMS, were synthesized by graft-co-polymerization of fluoroacrylate (PFA) and oligo dimethylsiloxane (DMS), and methylmethacrylate (MMA), respectively. The contact angle of water on the surface of the air-side of the surface-modified PTMSP membranes increased by the addition of PFA-g-PDMS and PMMA-g-PDMS. These results suggest that the surface-modified PTMSP membranes were more hydrophobic. Also, X-ray photoelectron spectroscopy (XPS) measurements supported that the polymer additives were concentrated at the surface of the air-side of the modified PTMSP membranes. The ethanol/water selectivity of the PTMSP membrane modified with PFA-g-PDMS increased significantly without a large decrease in flux compared with that of the PTMSP membrane. On the other hand, after modification of PTMSP with PMMA-g-PDMS both the flux and ethanol/water selectivity had a maximum at a certain amount Of PMMA-g-PDMS. The ethanol/water selectivity of the modified membrane was higher than that of the PTMSP membrane. High ethanol/water selectivity of the surface-modified PTMSP membranes depended on the solubility selectivity of the permeating species.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

This paper describes simple surface modifications of polydimethylsiloxane (PDMS) membranes by adding hydrophilic and hydrophobic black copolymers containing a PDMS component before the formation of PDMS networks on stainless-steel plates. The relationship between the surface characteristics of the surface-modified PDMS membranes and their permselectivity for aqueous ethanol solutions by pervaporation are discussed. Contact angle measurements demonstrated that the addition of a hydrophilic block copolymer made the stainless-steel-side surface of the PDMS membrane very hydrophilic. On the other hand, addition of a hydrophobic block copolymer produced a hydrophobic surface at its air contact side. Making the membrane surface hydrophilic gave the PDMS membrane a higher water-ethanol selectivity. On the other hand, introducing a very hydrophobic surface improved its ethanol-water selectivity without lowering its flux. Our results suggest a novel concept for designing the structure of high-performance, talior-made pervaporation membranes, that is, a method for controlling the permselectivity of a pervaporation membrane without lowering its permeability.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

The annealing effects of block and graft copolymer membranes consisting of ethanol-permselective poly(dimethylsiloxane) (PDMS) plus water-permselective poly(methyl methacrylate) (PMMA) on their permselectivity for an aqueous ethanol solution in pervaporation were investigated in terms of their microphase separation. The ethanol-permselectivity of the block copolymer membranes was strongly influenced by the annealing, but that of the graft, copolymer membranes was not. The original block copolymer membranes changed from water- to ethanol-permselectivity at a DMS content of 55 mol %, but the annealed block copolymer membranes changed at a DMS content of 37 mol %. Transmission electron micrography demonstrated that the annealing of the block copolymer membranes with a DMS content between 37 and 55 mol % resulted in dramatic changes in the morphology of their microphase separation. However, the annealing of the graft copolymer membranes had very little effect on the morphology of their microphase separation, which was quite different from the morphology of the block copolymer membranes. The analysis using a combined model consisting of parallel and series models revealed that a continuous PDMS phase in the direction of the membrane thickness is readily formed by the annealing of the block copolymer membranes. As a result, the continuity of the PDMS phase in the microphase separation governed the ethanol-permselectivity of these membranes for an aqueous ethanol solution. This report concludes that the morphological design of microphase-separated membranes, which can be achieved by membrane annealing, is very important in controlling their permeability and permselectivity.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCI LTD  

In order to improve surface property of poly[1-(trimethylsilyl)-1-propyne] (PTMSP) membranes, surface-modified PTMSP membranes were prepared by adding a small amount of a polymer additive, which is a graft copolymer PFA-g-PDMS, consisting of poly(fluoroacrylate) (PFA) and poly(dimethylsiloxane) (PDMS), in a casting solution of PTMSP. Contact angles for water on air and glass plate sides in the preparation of surface-modified PTMSP membranes were significantly different and those on the air side were more hydrophobic, and the contact angles for water increased with increasing additional amount of PFA-g-PDMS. High hydrophobicity of the membrane surface on the air-side and the increase in hydrophobicity with an increase of the additional amount of polymer additive were also confirmed by X-ray photoelectron spectroscopy. The permeation rate for an aqueous solution of 10 wt% ethanol in pervaporation of the surface-modified PTMSP membranes decreased slightly but ethanol permselectivity increased considerably with the increase of the additional amount of PFA-g-PDMS. Published by Elsevier Science Ltd. (C) 1999 Elsevier Science Ltd. All rights reserved.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

Benzoylcellulose (BzCell) membranes with different degrees of benzoylation were synthesized for the separation of benzene/cyclohexane (Bz/Chx) mixtures. A BzCell membrane with a degree benzoylation of 2 showed high benzene-permselectivity for B2/Chx mixtures in pervaporation. The permeation rate of the BzCell membrane increases, but the benzene-permselectivity decreases, with increasing benzene concentration in the feed mixture. This increase in the permeation rate is due to an increase in the swelling of the membrane, whereas the benzene-permselectivity was attributed to a decrease in the sorption selectivity. With increasing benzoylation of the BzCells, the permeation rate increases significantly, but the benzene-permselectivity decreases slightly. These results can be explained by the degree of swelling, the density, and the contact angle of the BzCell membranes.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：KLUWER ACADEMIC PUBL  

Tosylcelluloses (TosCells) with different degrees of tosylation were synthesized as membrane materials for the separation of benzene/cyclohexane (Bz/Chx) mixtures. TosCell membranes showed a high benzene-permselectivity for the Bz/Chx mixtures in pervaporation (PV). An increase in the benzene concentration in the feed mixtures increased permeation rate but decreased the benzene-permselectivity of the TosCell membranes. The increase in the permeation rate was attributed to the increase of the degree of swelling of the TosCell membranes by the feed mixtures and the decrease in the benzene-permselectivity was mainly caused by the decrease of sorption selectivity. With low benzene concentrations in the Bz/Chx mixtures, the permeation rate of a TosCell membrane with a higher degree of tosylation was greater than that with a lower degree of tosylation, but was vice versa with a high benzene concentration. The benzene-permselectivity of the former TosCell membrane was higher than that of the latter membrane. Differences of the permeation rate and benzene-permselectivity with changes in the benzene concentration in the feed mixture and degree of tosylation of the TosCell membrane were significantly influenced by the degree of swelling of the TosCell membrane and the benzene concentration sorbed into the TosCell membrane. Mechanism of separation for the Bz/Chx mixtures through the TosCell membranes is discussed by the solution-diffusion model.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：JOHN WILEY & SONS INC  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：MACMILLAN MAGAZINES LTD  

Stimuli-responsive hydrogels that undergo abrupt changes in volume in response to external stimuli such as pH, temperature and solvent composition have potential applications in biomedicine and the creation of 'intelligent' materials systems, for example as media for drug delivery, separation processes and protein immobilization. Hydrogels have been reported that respond to pH(1-3), temperature(4-13), electric fields(14-16) and saccharides(17-22). For some biomedical applications it would be very useful to have a material whose swelling response was dictated by a specific protein. Here we report such a material, which swells reversibly in a buffer solution in response to a specific antigen. The hydrogel was prepared by grafting the antigen and corresponding antibody to the polymer network, so that binding between the two introduces crosslinks in the network. Competitive binding of the free antigen triggers a change in gel volume owing to breaking of these non-covalent crosslinks. In addition, we show that the hydrogel displays shape-memory behaviour, and that stepwise changes in antigen concentration can induce pulsatile permeation of a protein through the network.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

The permselectivity of block copolymer membranes consisting of ethanol-permselective poly(dimethylsiloxane) (PDMS) plus water-permselective poly(methyl methacrylate) (PMMA) was compared to the permselectivity of graft copolymer membranes for the separation of an aqueous ethanol solution. This paper focuses on the difference in molecular architecture between the block and graft copolymers and relates microphase separation in these membranes to their permeability and permselectivity for an aqueous ethanol solution in pervaporation, With increasing DMS content, the block copolymer membranes changed from water- to ethanol-permselective at a DMS content of 55 mol %, As reported in a previous paper, however, the graft copolymer membranes showed a dramatic change in the permselectivity at a DMS content of 35 mol %. Transmission electron micrography demonstrated that both membranes had distinct microphase separation consisting of PDMS and PMMA phases and that the morphology was quite different between the block and graft copolymer membranes. The morphological changes in these membranes were investigated by image processing of the micrographs and analysis using a combined model consisting of both parallel and series models. These investigations revealed that the percolation transition of the PDMS phase in the block and graft copolymer membranes takes place at a DMS content of about 55 and 35 mol %, respectively. This suggests that the continuity of the PDMS phase in the microphase separation strongly influences the ethanol permselectivity of these membranes for an aqueous ethanol solution. This report concludes that the design of the molecular architecture in multicomponent polymer membranes is very important in controlling membrane characteristics which are governed by microphase separation.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：JOHN WILEY & SONS INC  

Methyl methacrylate-methacrylic acid copolymer (MMA-MAA) membranes ionically crosslinked with Fe3+ and Co2+ ions (MMA-MAA-Fe3+ and -Co2+) were prepared, and characteristics of permeation and separation for a benzene/cyclohexane mixture of 50 wt % benzene through these membranes in pervaporation (PV) were studied. Although the introduction of the metal ions to the MMA-MAA membrane enhanced both benzene permselectivity and permeability for a benzene/cyclohexane mixture, the PV characteristics between the MMA-MAA-Fe3+ and -Co2+ membranes were significantly different. The difference in the PV characteristics between these membranes was strongly governed by the difference of these membrane structures based on the glass transition temperature, contact angle to methylene iodide, degree of swelling, and mixture composition absorbed in the membrane, and so on. (C) 1999 John Wiley & Sons, Inc.

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Language：Japanese   Publisher：合成樹脂工業協会  

DOI： 10.11364/networkpolymer1996.20.Supplement_33

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

When benzene/cyclohexane (Bz/Chx) mixtures were permeated through nematic and smectic side-chain liquid-crystalline polymer (n- and s-LCP) membranes under various conditions in pervaporation, the n- and s-LCP membranes exhibited a benzene-permselectivity for the Bz/Chx mixtures. The benzene-permselectivity of the n-LCP membrane changed from the sorption selectivity to the diffusion selectivity by the state-transformation of the membrane with an increase in the permeation temperature but the benzene-permselectivity of the s-LCP membrane was governed by the diffusion selectivity regardless of the state of the s-LCP membrane. At the low permeation temperature, the n-LCP membrane in the liquid-crystalline state exhibited a lower permeability and a higher permselectivity than the s-LCP membrane. However, at the high permeation temperature the relationship between the permeability and permselectivity of the n-LCP and s-LCP membranes in the liquid-crystalline state was vice versa. These results were led by the difference of the chemical and physical structure of the n-LCP and s-LCP membranes. (C) 1998 Elsevier Science B.V.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

When benzene/cyclohexane toluene/cyclohexane and o-xylene/cyclohexane mixtures are subjected to pervaporation through a side-chain liquid-crystalline polymer (LCP) membrane in the liquid-crystalline state, the permeation rate increases with increasing temperature and the LCP membrane exhibits permselectivity for the aromatic hydrocarbon. The permeation rate and permselectivity of the LCP membrane for each mixture decreases with increasing molecular size of the aromatic hydrocarbon in the binary feed mixture.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

Benzoylchitosans (BzCses) with a different degree of benzoylation were synthesized as membrane materials having a good durability for the separation of benzene/cyclohexane (Bz/Chx) mixtures. Characteristics of BzCs membranes such as contact angle, crystallinity and degree of swelling were significantly influenced by the degree of benzoylation. The BzCs membranes showed a high benzene-permselectivity for a Bz/Chx mixture of 50 wt% benzene in pervaporation and a difference of the benzene-permselectivity for the BzCs membranes with different degree of benzoylation corresponded to a difference in the physical structure of the membranes based on the characteristics of these membranes. When a Bz/Chx mixture of 50 wt% benzene was permeated through the BzCs membranes, permeation rate increased and benzene-permselectivity slightly decreased with increasing degree of benzoylation. These results are discussed from the viewpoints of chemical and physical structures of the BzCs membranes with different degree of benzoylation. (C) 1998 Elsevier Science B.V.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

A benzoylchitosan was synthesized as a membrane material for separation of benzene/cyclohexane mixtures. When the benzoylchitosan membrane was applied to the permeation and separation of benzene/cyclohexane mixtures in pervaporation, both the permeation rate and benzene concentration in the permeate increased with increasing benzene concentration in the feed, and thus this membrane showed benzene permselectivity. Characteristics of permeation and separation of benzene/cyclohexane mixtures through the benzoylchitosan membrane were analyzed by the solution-diffusion model. It was found that the benzene permselectivity was dependent on both the sorption selectivity and diffusion selectivity but was significantly governed by the latter. Also a tentative model for the benzene permselectivity is discussed.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：JOHN WILEY & SONS INC  

When a benzene/cyclohexane mixture of 10 wt % benzene was permeated through side-chain liquid-crystalline polymer (LCP) membranes by pervaporation at various temperatures, the permeation rate increased with increasing permeation temperature. The LCP membranes also exhibited a benzene permselectivity. The permselectivity for the benzene/cyclohexane mixture through the LCP membrane was different in the glassy, liquid-crystalline, and isotropic states. The LCP membrane had different apparent activation energies for permeation at each state. LCP membrane in the liquid-crystalline state had the highest apparent activation energy of the three states. Results suggest that the benzene permselectivity was influenced by changes in the LCP membrane structure, i.e., a state-transformation. It was found that a balance of the orientation of mesogenic groups and the flexibility of the siloxane chains was very important for benzene permselectivity. (C) 1998 John Wiley & Sons, Inc.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：SPRINGER VERLAG  

When a benzene/cyclohexane mixture was permeated through poly (dimethyl acrylamide-random-methyl methacrylate) (DMAA-r-MMA) and poly (dimethyl acrylamide)-graft-poly (methyl methacrylate) (DMAA-g-MMA) membranes by pervaporation, the benzene-permselectivity of the DMAA-r-MMA membrane changed from the diffusivity selectivity to the solubility selectivity with increasing DMAA content but DMAA-g-MMA membranes with a high DMAA content had the higher apparent diffusivity selectivity than the apparent solubility selectivity. Furthermore, the apparent solubility selectivity for a benzene/cyclohexane mixture between the DMAA-r-MMA membrane and the DMAA-g-MMA membrane with a high DMAA content was remarkably different. These results were attributed to the difference of structure between the copolymers.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

Poly(methyl methacrylate) (PMMA) and poly(ethyl methacrylate) (PEMA) which have strong affinity for benzene were selected as membrane materials and the characteristics of permeation and separation for the benzene/cyclohexane mixtures through these poly(alkyl methacrylate) cross-linked with ethylene glycol dimethacrylate (EGDM) membranes by pervaporation were investigated. The cross-linked poly(alkyl methacrylate) membranes exhibited a benzene permselectivity for the benzene/cyclohexane mixtures and the permeation rate increased with increasing benzene in the feed solution. The permselectivity of their membranes was strongly governed by the diffusion separation process depending on the difference of the molecular size between the benzene molecule and the cyclohexane molecule. The depression of swelling of those membranes with the increase of the cross-linker content in the benzene/cyclohexane mixtures enhanced the benzene permselectivity. This result was attributed to the increase of the selectivity in the sorption separation process with the depression of swelling of the membrane. Furthermore, the cross-linked copolymer (PMMA-PEMA-EGDM) membranes showed excellent benzene permselectivity. These results suggested that both, the increase of affinity of the membrane for benzene and depression of swelling of the membrane, were very important in the separation of the benzene/cyclohexane mixtures.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCI LTD  

Synthetic polysaccharides have been found to be useful for basic biomedical research and practice medical applications. Those polysaccharides having a backbone consisting of a synthetic polymer are called 'glycopolymers'. Most glycopolymers are linear synthetic polymers with pendent mono-, oligo- and polysaccharides. Saccharide units in glycopolymers are recognized by a variety of carbohydrate receptors in a similar manner to natural polysaccharides. Investigation of glycopolymers has significantly contributed to our understanding of biochemical phenomena in relation to cell-cell interactions through molecular recognition. Furthermore, the properties of glycopolymers suggest that they have much potential as suitable materials for biochemical and biomedical applications, such as protein separation, cell culture and drug-delivery systems. This article provides a short overview of current research in the synthesis of glycopolymers and their applications to be biochemical and biomedical fields.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：JOHN WILEY & SONS INC  

Urease-immobilized ethylene-vinyl alcohol copolymer (EVA) membrane was prepared by the covalent bonding of urease on EVA membrane activated with cyanuric chloride. The urease-immobilized EVA membrane had optimum pH at about 7.0 similar to native urease. The Michaelis constant (K-m) and the maximum velocity (V-m) of the urease-immobilized EVA membrane were smaller than those of native urease. When the EVA membrane, prepared on a polyethylene (PE) plate by the phase inversion method, was used as a support, urease was asymmetrically distributed in the direction of cross section of the urease-immobilized EVA membrane. The permeation decomposition of urea through the asymmetrically urease-immobilized EVA membrane depended on the asymmetric distribution of urease in the membrane. (C) 1997 John Wiley & Sons, Inc.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：JOHN WILEY & SONS INC  

The side-chain Liquid-crystalline polymer (LCP) was synthesized by the addition of the mesogenic monomer to poly (methylsiloxane) with Pt catalyst. When the benzene/cyclohexane mixtures were permeated through the LCP membranes by pervaporation at various temperatures, the permeation rate increased with increasing benzene concentration in the feed solution and permeation temperature. Though the LCP membranes exhibited a benzene permselectivity, a mechanism of the permeation and separation for the benzene/cyclohexane mixtures was different in the glassy, liquid-crystalline and isotropic state of the LCP membranes. These results suggested that the permselectivity was fairly influenced by the change of the LCP membrane structure, that is, a state transformation. It was found that a balance of the orientation of mesogenic groups and flexibility of siloxane chains is very important for the permeability and selectivity. (C) 1997 John Wiley & Sons, Inc.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

N-Alkyl chitosans with different numbers of carbons and degrees of substitution of the N-alkyl group were prepared. The water-permselectivity for aqueous ethanol solutions through the N-alkyl chitosan membranes in evapomeation were studied. The permeation rate and separation factor for water-permselectivity were significantly influenced by the number of carbons in the N-alkyl group, in particular, one N-alkyl chitosan membrane showed a maximum in the permeation rate and separation factor. The degree of substitution in the N-alkyl group little affected the permeation rate, but significantly changed the separation factor. The characteristics of permeation and separation for an aqueous ethanol solution through the N-alkyl chitosan membranes with different N-alkyl groups and different degrees of substitution of the N-alkyl group an discussed from the viewpoints of physical and chemical structures of their membranes, such as, density, crystallinity, surface free energy and degree of swelling of the membrane.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：VSP BV  

To develop a polymeric matrix for efficiently loading cationic biomolecules, polyelectrolyte hydrogels carrying pendant phosphate groups were synthesized by copolymerizing 2-methacryloyloxyethyl dihydrogen phosphate with N-isopropylacrylamide and N,N'-methylene-bis-acrylamide. The phosphate carrying monomer yielded anionic hydrogels, which formed ionic complexes with the cationic protein, lysozyme. It was shown that the amount of complexed lysozyme reached 2.1 g g(-1) dry gel, corresponding to 1.3 x 10(-3) mol phosphate group per gram lysozyme, when 40 mol% of phosphate-carrying monomer was incorporated in a hydrogel. When the hydrogel complexed with lysozyme was placed in deionized water and various KCI solutions, of varying concentrations of up to 0.5 M KCI, no lysozyme was released in deionized water, while increasing amounts of lysozyme were released as the KCI concentration increased. This confirmed that lysozyme was loaded in the hydrogel through electrostatic interactions. It was further found that the complexed lysozyme retained its enzymatic activity after being released from the hydrogel. These results suggest the use of this system for the controlled release of cationic protein drugs.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Craft copolymer membranes consisting of both ethanol- and water-permselective components for the separation of aqueous ethanol solutions were prepared by the copolymerization of an oligo-dimethylsiloxane (DMS) macromonomer with methyl methacrylate (MMA). This paper describes the relationship between microphase separation in MMA-g-DMS membranes and their permselectivity for aqueous ethanol solutions by pervaporation. The MMA-g-DMS membranes changed drastically from water to ethanol permselective according to the DMS content. Using a transmission electron microscope, appreciable microphase separation was observed in the MMA-g-DMS membranes. The change in the permselectivity of the MMA-g-DMS membranes could be explained by morphological changes in the microphase separation, based on Maxwell's model and a combined model consisting of both parallel and series models. Furthermore, image processing of the transmission electron micrographs enabled us to reveal the percolation transition of the DMS phase at a DMS content of about 40 mol %. These results suggest that the continuity of DMS phases in the microphase separation of MMA-g-DMS membranes directly affects their permselectivity for aqueous ethanol solutions.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：HUTHIG & WEPF VERLAG  

The characteristics of permeation and separation for xylene isomers through poly(vinyl alcohol) membranes containing cyclodextrin (CD-PVA membranes) were investigated by pervaporation and evapomeation. Evapomeation is more effective for the separation of xylene isomers through the CD-PVA membrane than pervaporation. An increase in CD content gives rise to an increase in a p-xylene-permselectivity through the CD-PVA membrane by evapomeation. This is attributed to the stronger affinity of CD for p-xylene as compared with o-xylene. Especially, the CD-PVA membrane at a CD content of 40 wt.-% shows a higher separation factor than has ever been reported. When the p-xylene concentration in the feed is lower, the p-xylene-permselectivity is improved. The mechanism of permeation and separation for xylene isomers is discussed from the standpoint of solution-diffusion theory.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：JOHN WILEY & SONS INC  

Polydimethylsiloxane (PDMS)/polystyrene (PSt) interpenetrating polymer network (IPN) membranes were prepared by the bulk copolymerization of styrene and divinylbenzene in the PDMS networks. The interpenetration of PDMS and PSt resulted in the improvement of mechanical properties of PDMS. Transmission electron microscope (TEM) observation demonstrated that the PDMS/PSt IPN membranes have microphase-separated structures consisting of a continuous PDMS phase and a discontinuous PSt phase. When an aqueous ethanol solution was permeated through the PDMS/PSt IPN membranes by pervaporation, the PDMS/PSt IPN membranes exhibited ethanol permselectivity, regardless of the PDMS content. The effects of their microphase-separated structures on the permeability and selectivity for aqueous ethanol solutions are discussed experimentally and theoretically. (C) 1996 John Wiley & Sons, Inc.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：HUTHIG & WEPF VERLAG  

A side-chain liquid-crystalline polymer (LCP) was synthesized by the addition of the mesogenic monomer to poly (methyl siloxane) in presence of a Pt-catalyst. When an aqueous solution of 10wt% ethanol was permeated through a LCP membrane by pervaporation at various temperatures, the permeation rate increased with increasing temperature and drastically changed at glass-nematic (Tg) and nematic-isotropic (TNI) transition temperatures of the LCP membrane. The LCP membrane exhibited the water-permselectivity in the glassy and liquid-crystalline states. The ethanol concentration in the permeate increased with increasing permeation temperature and the LCP membrane changed from the water-permselectivity to the ethanol-permselectivity around TNI. These results suggested that the permselectivity was influenced by the change of the LCP membrane structure, that is, its state transformation. It was found that a balance of the orientation of mesogenic groups and flexibility of siloxane chains is very important for the permeability and selectivity.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：HUTHIG & WEPF VERLAG  

Uphill transport of ammonium ions through a membrane with sulfonic acid groups were investigated with pH-controllers which keep the solution at a constant pH. A membrane with sulfonic acid groups was prepared by casting an aqueous solution containing poly(styrenesulfonic acid) and poly(vinyl alcohol) on a glass plate. When a membrane with one side alkaline and the other acidic was fixed as a diaphragm in a cell, ammonium ions were transported from the alkaline side to the acidic side through the membrane against the concentration gradient of the adjacent solutions. Uphill transport of ammonium ions with pH-controllers was more efficient than without, thus keeping the pH difference between both sides of the membrane constant, which is a driving force for the uphill transport. Furthermore, the effect of pH of the acidic side on the uphill transport was investigated and the mechanism of the pH-controlled uphill transport is discussed.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：HUTHIG & WEPF VERLAG  

A glucose-sensitive hydrogel was prepared by introducing concanavalin A (Con. A) into poly(2-glucosyloxyethyl methacrylate) (poly(GEMA)) hydrogel. The decrease in swelling ratio and increase in crosslinking density by introduction of Con. A into the poly(GEMA) hydrogel indicate that the complexation introduces additional crosslinking points. The swelling of the hydrogel increased in the presence of glucose, and the swelling ratio was dependent on the glucose concentration. The glucose sensitivity of the hydrogel is attributable to the dissociation of the complex between poly(GEMA) and Con. A in the presence of glucose. Furthermore, the poly(GEMA)-Con. A complex hydrogel was responsive sive to the kind of monosaccharide; its swelling ratio was changed by the presence of glucose or mannose, but not by the presence of galactose. The swelling properties of this hydrogel might be useful for the development of a glucose-sensitive device.

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：SPRINGER-VERLAG  

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Language：Japanese   Publisher：関西大学工業技術研究所  

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：SPRINGER-VERLAG  

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Language：Japanese   Publisher：The Society of Polymer Science, Japan  

DOI： 10.1295/kobunshi.44.612

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Other Link： https://jlc.jst.go.jp/DN/JALC/00034945162?from=CiNii

Language：English   Publishing type：Research paper (scientific journal)   Publisher：JOHN WILEY & SONS INC  

Glucosyloxyethyl methacrylate (GEMA) was copolymerized with butyl acrylate (BA) for the preparation of a biomedical pressure-sensitive adhesive with pendant monosaccharides, for possible use in medical applications. The measurements of 180 degrees peel strength, ball tack, and holding power for the GEMA-BA copolymer films revealed that the film at the GEMA content of 5 mol % has excellent pressure-sensitive adhesive properties. Protein adsorption onto the GEMA-BA copolymer film hardly occurred due to very low interfacial free energy between its surface and water. Release profiles of vitamin B-12 from the GEMA-BA copolymer film suggests that it is useful as a material for a transdermal therapeutic system. (C) 1995 John Wiley and Sons, Inc.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：HUTHIG & WEPF VERLAG  

Poly(methyl methacrylate) with oligodimethylsiloxane grafts (MMA-g-DMS) was prepared by copolymerization of a dimethylsiloxane (DMS) macromonomer with methyl methacrylate (MMA). Two glass transition temperatures (T-g) were observed at about 120 degrees C and -127 degrees C in all graft copolymer membranes. Transmission electron micrographs demonstrate that the MMA-g-DMS membranes show microphase separation. When an aqueous solution of 10 wt.-% ethanol was applied to permeations through the MMA-g-DMS membranes by pervaporation, the ethanol concentration in the permeate and the permeation rate increased drastically with the DMS content in the copolymer. Especially while at a DMS content of less than 40 mol-% preferentially water permeates from an aqueous solution of 10 wt.-% ethanol, the membranes with more than about 40 mol-% of DMS show ethanol-permselectivity. The relationship between the microphase-separated structures and the permeation characteristics for an aqueous ethanol solution is discussed.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：HUTHIG & WEPF VERLAG  

Protein adsorption on copolymer films having pendant monosaccharide groups was investigated from the viewpoint of surface chemistry. The copolymers were synthesized by the copolymerization of a monomer having a pendant monosaccharide (GEMA) and methyl methacrylate (MMA). The contact angles of methylene iodide and air bubble on the GEMA-MMA copolymer films were measured in water, and the surface free energy of the copolymer films in water was calculated from the contact angles. With increasing GEMA content, the amount of protein adsorbed on the GEMA-MMA copolymer films decreased gradually. The relationship between protein adsorption and the surface free energy of the copolymer films in water is discussed. The difference between surface free energy before and after protein adsorption on the copolymer surface is closely related to the amount of adsorbed protein.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：HUTHIG & WEPF VERLAG  

Copolymers having pendant monosaccharide groups were synthesized by copolymerizing 2-(glucosyloxy)ethyl methacrylate (GEMA, 1), with methyl methacrylate (MMA) or styrene (St). The surface characteristics of the copolymer films were investigated by means of contact angle measurements, X-ray photoelectron spectroscopy (XPS), and protein adsorption. The surface free energy of the GEMA/St copolymer films was constant in the range of a GEMA content from 10 mol-% to 60 mol-%. Insertion of GEMA of over 60 mol-%, however, caused an increase of the surface free energy of the copolymer films. The surface composition determined by means of XPS supported the result from surface free energy measurements. There was a significant difference between the GEMA/St and GEMA/MMA copolymer films in the effect of the GEMA content on the surface characteristics of the films. The differences could be explained on the basis of the sequence of monomeric units in each copolymer. Immersing the copolymer films in hot water made the copolymer surface more hydrophilic. This is because each component migrates to the surface or the bulk in order to minimize the surface free energy of the copolymer films. The introduction of GEMA to the copolymer suppressed fibrinogen adsorption onto the copolymer films.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：HUTHIG & WEPF VERLAG  

We copolymerized a monomer with a pendant glucose unit (GEMA) with methyl methacrylate (MMA) and prepared copolymer films with pendant monosaccharides by casting the copolymer solution on glass plates. The surfaces of the copolymer films were characterized by contact angle measurements, X-ray photoelectron spectroscopy (XPS) and protein adsorption measurements, and compared with the surface of 2-hydroxyethyl methacrylate (HEMA)-MMA copolymer films. The surface free energy of the GEMA-MMA and HEMA-MMA copolymer was calculated from the contact angle of methylene diiodide and glycerol on the copolymer films. The surface free energy of the films increased gradually with increasing GEMA or HEMA content. The surface free energy of GEMA-MMA copolymers was larger than that of HEMA-MMA copolymers in the whole range of composition. The results of XPS measurements suggest that the fraction of GEMA at the copolymer surface increases as the content of GEMA in the copolymer increases. This indicates that introduction of GEMA makes the copolymer surface more hydrophilic. Furthermore, the higher the GEMA content is, the smaller amounts of fibrinogen and gamma-globulin are adsorbed at the copolymer surface. The copolymer with a GEMA content of 20 mol-% hardly adsorbs fibrinogen and gamma-globulin at all.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

The structure of chitosan membranes chemically modified with aldehydes, such as glutaraldehyde and n-butyl aldehyde, was analyzed. Characteristics of permeation and separation of aqueous ethanol solutions through the membranes were investigated by evapomeation. Chitosan membranes reacted with glutaraldehyde were cross-linked by Schiff base bonds and had no pendant structure. Density and crystallinity of the cross-linked chitosan membranes decreased with increasing glutaraldehyde content in the membranes. The permeation rate, separation factor for water permselectivity, and degree of swelling of the cross-linked chitosan membrane for aqueous ethanol solutions increased with increasing glutaraldehyde content in the chitosan membrane. The structure of the chemically modified chitosan membrane and the permeation and separation characteristics for aqueous ethanol solutions are discussed from the viewpoint of hydrogen bonds of the cross-linked membrane.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：JOHN WILEY & SONS INC  

Poly (vinyl alcohol) membranes containing cyclodextrin (CD-PVA membrane) were prepared and characteristics of permeation and separation for propanol (PrOH) isomers through the CD-PVA membranes were investigated by pervaporation and evapomeation. Evapomeation was more effective for the separation of PrOH isomers through the CD-PVA membrane than was pervaporation. The CD-PVA membrane more preferentially permeated n-PrOH than i-PrOH from their mixtures. In particular, the mixture of 10 wt % n-PrOH concentration was concentrated to about 45 wt % through the CD-PVA membrane. Both permeability and selectivity for n-PrOH were improved with an increase of CD content in the membrane. The results were supported by the fact that the affinity of CD for n-PrOH was stronger than that for i-PrOH. The permeation mechanism of PrOH isomers through the CD-PVA membrane is discussed based on the solution-diffusion theory. (C) 1994 John Wiley & Sons, inc.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：VSP BV  

The complex formation between Concanavalin A (Con A) and a polymer having pendant glucose groups was studied in order to design a glucose-sensitive polymer. The polymer having pendant glucose (poly(glucosyloxyethyl methacrylate) or (poly(GEMA)) forms a complex with Con A in tris HCl buffer (pH = 7.5). The solution then becomes turbid due to the multiple associations between poly(GEMA) and Con A. When free glucose or mannose are added to the turbid solution, the solution becomes transparent again. However, the addition of galactose does not cause the solution to be transparent. This indicates that Con A prefers to form a complex with free glucose or mannose (but not galactose) rather than with the pendant glucose in poly(GEMA). Therefore, the complex between poly(GEMA) and Con A is expected to be glucose- and mannose-sensitive. The apparent dissociation constants of the complexes between saccharide (poly(GEMA), glucose, and mannose) and Con A were also determined by affinity electrophoresis.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：HUTHIG & WEPF VERLAG  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：HUTHIG & WEPF VERLAG  

The permeation and separation characteristics of poly(vinyl chloride) (PVC) and poly[(vinyl chloride)-co-(vinyl acetate)] (poly(VC-co-VAc)) membranes were investigated for aqueous organic acid solutions by pervaporation and evapomeation. The PVC membrane preferentially incorporates organic acids and predominantly permeates water from aqueous organic acid solutions. Water permselectivities of these aqueous solutions through the PVC membrane are significantly dependent on high diffusivity of water across the membrane. It was found that the permeation rate increases and the separation factor for the water permselectivity decreases with increasing vinyl acetate (VAc) content in the poly(VC-co-VAc) membrane. Preferential solubility of acetic acid into the poly(VC-co-VAc) membrane increases with the VAc content. This result was explained by a strong affinity between acetic acid and the VAc unit in the poly(VC-co-VAc) membrane.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

Surface characteristics of EVA membranes were investigated using ESCA. The membranes were prepared by dipping polymer solution cast on various substrates into a coagulation bath (the phase-inversion method). The ESCA results demonstrated that there were significant differences in the surface composition of EVA membranes prepared under various conditions. The more hydrophobic the substrate, the more the substrate side surface was enriched in the ethylene component. Thus the surface characteristics can be controlled by the kind of the substrate without changing the membrane structure such as pore size. For membranes subjected to hot water treatment, the composition of the substrate-contacting surface gradually approached that of the water side surface with increasing temperature. These results suggest that the ethylene and vinyl alcohol components migrated in order to lower the surface free energy at the surface of the membrane.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：HUTHIG & WEPF VERLAG  

An ethylene/vinyl alcohol copolymer (EVA)-copper complex membrane was prepared by casting an EVA-CuCl2 mixture (solvent:water-propanol (1 : 1 v/v) mixture) on a polyethylene substrate and then immersing it in 0,1 M KOH aqueous solution. In the membrane, Cu was distributed asymmetrically in the direction of the membrane cross section. The distribution of Cu could be controlled by the temperature during preparation. The oxidation of hydroquinone during permeation through the complex membrane was performed using membranes with different Cu distribution. This distribution influences the permeation reaction. These results are well reproduced by a relation composed of Fick's law and Michaelis-Menten type reaction kinetics. Therefore, a good reactor can be developed by controlling the catalyst distribution.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

Ethylene-vinyl alcohol copolymer (EVA) and ethylene-vinyl alcohol-acrylic acid terpolymer (EVA-AA) ultrathin membranes were prepared by spreading the polymer solutions on a water surface. The surfaces of the polymers were characterized by zeta-potential and ESCA measurements. The EVA membrane has nearly the same zeta-potential at both surfaces, that is, the air side and the water side surface. The results of the ESCA measurements demonstrated that the EVA membrane had more OH groups at the water side surface than at the air side surface. The EVA-AA membrane from DMSO solution had a higher zeta-potential on the water side surface than on the air side surface. However, the EVA-AA membrane from DMAc solution had the same zeta-potential on both surfaces. The ESCA measurement showed that EVA-AA membrane from DMSO solution had more than twice the amount of -COOH groups on the water side surface compared with the air side surface. On the other hand, in the membrane from DMAc solution the amount of COOH groups was observed to be the same at both sides.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：HUTHIG & WEPF VERLAG  

Hydrogels containing phosphate groups were prepared by copolymerization of 2-methacryloyl-oxyethyl dihydrogen phosphate (phosmer) and various hydrophilic monomers [N,N-dimethyl-acrylamide (DMAAm), acrylic acid (AAc) and 2-hydroxethyl methacrylate (HEMA)], and the swelling behavior was investigated. These hydrogels are thermo-sensitive. Phosmer-DMAAm and phosmer-HEMA hydrogel deswell with increasing temperature, but for the phosmer-AAc hydrogel the swelling ratio increases with temperature. Interestingly, the swelling ratio decreases with an increase in phosphate group content. This unusual behavior may arise from the phosphate group acting both as the functional group and the crosslinking agent.

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Publishing type：Article, review, commentary, editorial, etc. (scientific journal)  

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Language：Japanese   Publisher：関西大学先端科学技術推進機構  

CiNii Books

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Language：Japanese   Publisher：関西大学先端科学技術推進機構  

CiNii Books

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Language：Japanese   Publisher：関西大学先端科学技術推進機構  

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Language：Japanese   Publisher：関西大学先端科学技術推進機構  

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Language：Japanese   Publisher：関西大学先端科学技術推進機構  

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Language：Japanese   Publisher：関西大学先端科学技術推進機構  

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Language：English   Publisher：BEGELL HOUSE INC  

In order to obtain higher membrane performance in the concentration of bioethanol and dehydration of organic solvents, hydrophobic porous poly[1-(trimethylsilyl)-1-propyne] (PTMSP) and hydrophilic porous chitosan membranes, respectively are applied to a temperature-difference-controlled evapomeation (TDEV) method in which a temperature difference between the feed solution and the membrane surroundings is established, to selectively concentrate ethanol from aqueous ethanol solutions and dehydrate water in aqueous dimethyl sulfoxide solutions. Pressure treated porous PTMSP membranes showed a high ethanol concentration performance with a high permeation rate and porous chitosan membranes also showed a high dehydration performance in TDEV. Membrane performances through these porous membranes in TDEV are discussed from the viewpoints of chemical and physical structure of membranes and physicochemical property of permeants.

DOI： 10.1615/JPorMedia.2015012401

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Language：Japanese  

J-GLOBAL

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Language：Japanese   Publisher：関西大学先端科学技術推進機構  

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Language：English   Publishing type：Book review, literature introduction, etc.   Publisher：SOC POLYMER SCIENCE JAPAN  

This article provides a short overview of our research regarding the preparation of smart soft materials using molecular complexes that reversibly associate and dissociate in response to environmental changes. Stimuli-responsive hydrogels that show swelling/shrinking in response to pH and temperature were prepared by copolymerization of a monomer bearing a phosphate group and other various monomers. Hydrogels with phosphate groups were useful tools for the construction of self-regulated drug delivery systems. Furthermore, we proposed a strategy for the preparation of biomolecule-responsive hydrogels that use reversible crosslinks in the networks of biomolecular complexes. Based on this strategy, we have prepared two types of biomolecule-responsive hydrogel that undergo changes in volume in response to target biomolecules. This was accomplished using biomolecular complexes such as antigen-antibody complexes and saccharide-lectin complexes and both a biomolecule-crosslinked hydrogel and a biomolecule-imprinted hydrogel have been synthesized with this approach. Biomolecule-crosslinked hydrogels, such as glucose- and antigen-responsive hydrogels, swelled in the presence of a target biomolecule due to the dissociation of biomolecular complexes that act as reversible crosslinks. On the other hand, biomolecule-imprinted hydrogels, such as tumor marker glycoprotein-responsive hydrogels, shrank in response to a target biomolecule due to the formation of a complex between ligands (lectin and antibody) and the target biomolecule. Thus, biomolecule-responsive hydrogels have many potential applications as smart biomaterials in biomedical fields. Although most smart soft materials prepared using molecular complexes still require further research, they are likely to become important materials in the future. Polymer Journal (2010) 42, 277-289; doi:10.1038/pj.2010.12; published online 10 March 2010

DOI： 10.1038/pj.2010.12

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