Hydroxyl Groups Of PVA Research Articles

Interface Porcelain Tile/PVA Modified Mortar: A Novel Nanostructure Approach

In ceramic tile systems, the overall result of adherence between porcelain tiles and polymer modified mortars could be explained based on the nano-order structure that is developed at the interface. Based on pull-off tests, Scanning Electron Microscopy images, and Small Angle X-ray Scattering experiments a nanostructured approach for interface tile/PVA modified mortar was built. The increase of adhesion between tile and mortar due to poly(vinyl alcohol), PVA, addition can be explained by the formation of a hybrid ceramic-polymer-ceramic interface by hydrogen bonds between PVA hydroxyl groups and silanol from tile surface and water from nanostructured C-S-H gel interlayer.

Enabling Thermoreversible Physically Cross-Linked Polymerized Colloidal Array Photonic Crystals

We physically cross-linked a thermoreversible poly(vinyl alcohol) (PVA) hydrogel (TG) within a crystalline colloidal array (CCA) to form an enabling photonic crystal material. The TG consists of a physically cross-linked network formed in a process reminiscent of the well-known freeze-thaw physically cross-linking process, but which avoids solvent freezing which invariably disorders the CCA. These TGCCA can be inexpensively fabricated in any large volume and shape by avoiding the previous covalently polymerized CCA constraints that required thin sheet geometries to enable penetration of the UV light used to photopolymerize the system. This TG hydrogel enables rigidificaton of CCA crystals and subsequent chemical functionalization. In addition, an additional interpenetrating hydrogel can be polymerized within the TGPCCA. The TG can then be dissolved away by simply increasing the temperature. The TGCCA photonic crystal diffraction is highly efficient and similar to previously demonstrated PCCA with covalent cross-links. These TGCCA are stable for weeks or longer at room temperature and can be utilized as photonic crystal materials. They also can be irreversibly covalently cross-linked by using gluteraldehyde. These gluteraldehyde cross-linked TGCCA can be made into chemically responsive sensor photonic crystals by functionalizing the PVA hydroxyl groups with chemical recognition agents. We demonstrate low and high pH sensing by functionalizing with carboxylates and phenol derivatives, respectively.

Surface immobilization of biocompatible phospholipid polymer multilayered hydrogel on titanium alloy

The aim of this study is to improve the biocompatibility of titanium alloy (Ti) implants by immobilization of multilayered phospholipid polymer hydrogel able to reduce protein adsorption and cell adhesion. We fabricated and characterized a multilayered hydrogel on Ti substrate via a layer-by-layer self-assembly deposition method using a phospholipid polymer bearing a phenylboronic acid moiety and poly(vinyl alcohol) (PVA). The water-soluble phospholipid polymer (PMBV) was synthesized from 2-methacrylocyloxyethyl phosphorylcholine, n-butyl methacrylate, and 4-vinylphenylboronic acid (VPBA). The PMBV reacted with PVA and formed a hydrogel due to covalent linkage between the VPBA units and hydroxyl groups of PVA. The hydrogel layer growth on the Ti surface was initialized by the deposition of one layer of photoreactive PVA bonded by UV irradiation to the Ti surface, which was modified with an alkylsilane compound. The multilayered hydrogel was built up by alternating the deposition of the PMBV and PVA; this was monitored by several methods: static contact angle measurement, X-ray photoelectron spectroscopy, and attenuated Fourier-transform infrared spectroscopy. The results revealed clearly the progressive construction of the multilayered hydrogel on the Ti substrate. The PMBV/PVA multilayer prepared on the Ti substrate reduced the adhesion of L929 cells compared with that on an untreated Ti substrate. Thus, we concluded that the formation of the multilayered hydrogel is effective to improve the biocompatibility on Ti-based medical devices.

Multiple hydrophilic polymer ultra-thin layers covalently anchored to polyethylene films

A novel procedure has been developed to covalently graft multiple hydrophilic polymer ultra-thin layers to functionalized polyethylene surface. Polyethylene films have been functionalized by two methods, chromic acid oxidation and maleic anhydride grafting, to produce surfaces containing reactive groups, carboxylic acid and anhydride, respectively. The reactive groups formed in the functionalization were used to anchor a poly(vinyl alcohol) (PVA) ultra-thin layer by thermal esterification. After anchoring PVA, a second ultra-thin layer, constituted of poly(acrylic acid) (PAA), was also anchored. The second layer was anchored by thermal esterification between PVA hydroxyl groups and PAA carboxylic acid groups. The procedure presented in this work allows the formation of an ultra-thin layer. The macromolecule anchoring reactions occur only at the interfaces, consequently, only the macromolecules in contact with the interface are anchored. The formation of the ultra-thin layer and the surface characteristics have been analyzed through XPS, ATR-FTIR, SEM, and AFM data.

Self-assembled amphiphilic polyhedral oligosilsesquioxane (POSS) grafted poly(vinyl alcohol) (PVA) nanoparticles

In the present study, spherical nanoparticles (NPs) containing polyhedral oligosilsesquioxane (POSS) as an inner hydrophobic core and poly(vinyl alcohol) PVA as a hydrophilic outer shell were prepared by dialysis approach. Preparation of amphiphilic POSS-grafted-PVA co-polymer was characterized by 1H NMR and FT-IR. The results indicated urethane linkage between monoisocyanate group of POSS macromer and the hydroxyl groups of PVA. The dynamic light scattering (DLS) and electrophoretic light scattering (ELS) of the NPs revealed that they have an average hydrodynamic diameter and negative zeta ( ζ)-potential of 215 nm and − 161 mV, respectively. Atomic force microscopy (AFM) and bio-transmission electron microscope (BIO-TEM) have shown unagglomerated NPs within a diameter range of 60–90 nm. The prepared NPs were investigated to improve the control release of anticancer drug; paclitaxel as a model drug. Due to drug loading, the hydrodynamic diameter and negative zeta ( ζ)-potential have changed to 325 nm and − 14 mV, respectively. In addition, in-vitro drug release experiments were conducted; the obtained results explicated continuous release for over 40 days. However, in case of using pure drug only, the drug completely released within 1 h.

Swelling and viscoelastic properties of poly(vinyl alcohol) physical gels synthesized using sodium silicate

A physically crosslinked poly(vinyl alcohol) (PVA) gel was synthesized from mixed aqueous solutions of PVA and sodium silicate (SS) using freeze/thaw techniques. The infrared spectroscopy, swelling and viscoelastic properties of the resultant gel have been investigated. The infrared spectrum of the resultant gel was as in the spectrum of PVA gel without SS. The resultant gel showed that the absorbing band due to stretching of hydroxyl groups shifted to a lower wave number, indicating the enhancement of hydrogen bonding between hydroxyl groups in PVA. Dynamic viscoelastic measurements showed that the storage modulus of the resultant gel was 1 order of magnitude higher than that of PVA gel without SS. The degree of swelling Q varied with the SS concentration c SS as Q ∼ c SS - ν (0.12 < ν < 0.37). The storage modulus at 1 Hz E′ changed by the degree of swelling Q satisfying with a power low as E′ ∼ Q −3.8. Microphotographs of the gels in a dry state showed that PVA network developed extensively as increasing the SS concentration. These results obtained strongly indicate that the resultant gel consists from only PVA, not composites of PVA and SS. It can be considered that SS hastens the aggregation or crosslinking of PVA chains; as a result physically crosslinked gels with close network and high elasticity were obtained. Reswelling experiment showed that the degree of swelling by the reswelling for the resultant gel was approximately 10, which was less than 1/6 of the original value of the degree of swelling.

Amphiphilic Poly(vinyl alcohol) Hybrids and Electrospun Nanofibers Incorporating Polyhedral Oligosilsesquioxane

Polyhedral oligosilsesquioxane (POSS)-containing amphiphilic poly(vinyl alcohol) (PVA) hybrids (PVA−POSS hybrids) were synthesized by urethane linkage between the hydroxyl groups of PVA and the monoisocyanate group of POSS macromers. The hydrophobicity of the amphiphilic PVA−POSS hybrids was varied by changing the incorporated amounts of the hydrophobic POSS macromers, resulting in control over water resistance. The synthesized amphiphilic PVA−POSS hybrids were characterized by 1H NMR, FT-IR, DSC, and TGA and revealed modified thermal stability and solubility depending on the incorporated amounts of POSS macromers. That is, modification in both solid form and solution is observed, which is attributed to the bulkiness and hydrophobicity of POSS moieties. As a result, the amphiphilic PVA−POSS hybrids with the molar ratio of POSS macromer to −OH mole of PVA ranging from 1.0 to 15.0 could be obtained. Amphiphilic PVA−POSS hybrids showed microstructural features characteristic structure of two separate crystalline components, that is, the dual system of PVA and POSS crystalline phases. In addition, the electrospun nanofibers of PVA−POSS hybrids suggest a new method to enhance/control the water resistance of PVA nanofibers without cross-linking.

Study of electrospinning of sodium alginate, blended solutions of sodium alginate/poly(vinyl alcohol) and sodium alginate/poly(ethylene oxide)

AbstractAlginate is an interesting natural biopolymer for many of its merits and good biological properties. This paper investigates the electrospinning of sodium alginate (NaAlg), NaAlg/PVA‐ and NaAlg/PEO‐ blended systems. It was found in this research that although NaAlg can easily be dissolved in water, the aqueous NaAlg solution could not be electrospun into ultrafine nanofibers. To overcome the poor electrospinnability of NaAlg solution, synthetic polymers such as PEO and PVA solutions were blended with NaAlg solution to improve its spinnability. The SEM images of electrospun nanofibers showed that the alginate (2%, w/v)–PVA (8%, w/v) blended system in the volume ratio of 70 : 30 and the alginate (2%, w/v)–PEO (8% w/v) blended system in the volume ratio of 50 : 50 could be electrospun into finest and uniform nanofibers with average diameters of 118.3 nm (diameter distribution, 75.8–204 nm) and 99.1 nm (diameter distribution, 71–122 nm), respectively. Rheological studies showed a strong dependence of spinnability and fiber morphology on solution viscosity and thus on the alginate‐to‐synthetic polymer (PVA or PEO) blend ratios. FTIR studies indicate that there are the hydrogen bonding interactions due to the ether oxygen of PEO (or the hydroxyl groups of PVA) and the hydroxyl groups of NaAlg. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007

Preparation of crosslinked chitosan/poly(vinyl alcohol) blend beads with high mechanical strength

Crosslinked chitosan beads reported in the literature have the disadvantage of high water content and thus low mechanical strength. In this paper, a chitosan/poly(vinyl alcohol) (PVA) blend aqueous solution was first suspended in toluene–chlorobenzene to form droplets. Some of the water was then distilled out as an azeotrope with the aromatic hydrocarbons to reduce the water content of the suspension droplets. Glutaraldehyde was finally added to the suspension to result in the crosslinked chitosan/PVA beads with low water content and high mechanical strength. It was found that glutaraldehyde reacted with PVA to form crosslinkage at acidic conditions (pH 1 and 2). The H+ ions act as both protection agents of amino groups of chitosan by forming salts and catalyst for the formation of acetal between aldehyde groups and hydroxyl groups of PVA. At pH 4 and 5, glutaraldehyde reacted with chitosan to form Schiff's base crosslinkage. Crosslinked chitosan/PVA beads with micron size were also prepared by the distillation method using very dilute initial polymer concentration and high stirring speed.

Functionalization of poly(vinyl alcohol) by addition of methacryloyl groups: characterization by FTIR and NMR and optimization of reaction conditions by RSM

AbstractThe modification of poly(vinyl alcohol) (PVA) with glycidyl methacrylate (GMA) in DMSO catalyzed by TEMED is reported in this paper. PVA was dissolved in DMSO and reacted with GMA at 30 ºC in a closed vessel under N2 gas bubbling for 24 hours. The reaction was characterized by FTIR and NMR (1H, 13C/DEPT and HETCOR) spectroscopies. The reaction occurs by transesterification through the insertion of methacryloyl groups into PVA chains and probably with the formation of glycidol as a by-product. The degree of substitution (DS) that represents the number of methacryloyl groups inserted was determined through 1H NMR spectra based on the ratio between the averaged area due to the vinyl hydrogen from methacryloyl groups at δ̣ 5.6 ppm and δ 6.0 ppm and the total area of the vinyl hydrogen and hydroxyl hydrogen of PVA. By use of response surface methodology the experimental conditions were optimized. The optimum conditions were 62 ºC with a reaction time of 6 hours. In these optimized conditions, the reactions using the molar ratios [-OH(PVA)/GMA] equal to 1/0.10, 1/0.25, 1/0.50, 1/0.75 and 1/1 were investigated. The response surface was based on the model DS= −19.70 + 6.09x10−1T +1.93 t − 3.89x10−3 T2 − 5.21x10−2t2 − 2.14x10−2 T * t, where T is the temperature (°C) and t the reaction time (hours). This model explained 99.20 % of the 99.64 % explainable statistical data. Using the optimized conditions, it is possible to produce a desired modified PVA, (or PVA-Ma), because DS raises linearly to the ratio [-OH(PVA)/GMA] up to 25 mol-% and the respective yield ranged from 83 to 92 %. It is difficult to obtain more than 50 mol-% substitution of PVA hydroxyl by methacryloyl groups even in these optimized conditions due to increased steric hindrance by the large number of the methacryloyl groups inserted into PVA.

Structure-property relationship in sol-gel derived polymer/silica hybrid nanocomposites prepared at various pH

This paper reports a comparative study on structure-property relationship of acrylic rubber (ACM)/silica, epoxidised natural rubber (ENR)/silica and poly (vinyl alcohol) (PVA)/silica hybrid nanocomposites prepared by sol-gel technique under different pH levels (pH = 1.0–13.0), probably for the first time. The initial concentration of tetraethoxysilane (TEOS) (used as the precursor for silica) was kept at 45 wt%, and tetrahydrofuran (THF) for ACM/silica and ENR/silica while water for PVA/silica were taken as solvents. TEOS to water mole ratio was maintained at 1:2 for the rubber/silica systems to accomplish the sol-gel reaction. The structure of the resultant hybrid composites was determined by using electron microscopy, Fourier Transform infrared spectroscopy and solubility. Dynamic mechanical and mechanical properties were also investigated. The silica particles were found to exist as nanoparticles (average diameter <100 nm) at low pH (≤ 2.0) beyond which these aggregate, although the amount of silica generation was not strictly influenced by the various pH conditions in all the systems. These nanocomposites were optically clear and showed superior mechanical reinforcement over the micro-composites containing aggregated silica structures with lower optical clarity. The nanocomposites exhibited higher storage modulus both at the glassy and the rubbery regions as compared to those micro-composites. The loss tangent peak heights were also minimum and the Tg shifted to higher temperature for those nanocomposites. The maximum improvement of mechanical properties was observed with the PVA/silica nanocomposites due to higher level of interaction between the hydroxyl groups of PVA and the silanol groups of the silica phase.

Nafion ®/poly(vinyl alcohol) blends: Effect of composition and annealing temperature on transport properties

In this study, the transport properties (proton conductivity and methanol permeability) of Nafion ® 117, solution-cast Nafion ®, poly(vinyl alcohol) (PVA) and Nafion ®/PVA blend membranes were measured as a function of annealing temperature (60–250 °C) and blend composition for application to the direct methanol fuel cell (DMFC). A Nafion ®/PVA blend membrane at 5 wt% PVA (annealed at 230 °C) resulted in similar proton conductivity, but three times lower methanol permeability compared to Nafion ® 117. In addition, an unusual trend was observed in Nafion ®/PVA (50 wt% PVA) blend membranes, where proton conductivity remained relatively constant, but methanol permeability decreased by approximately one order of magnitude with increasing annealing temperature. Infrared spectroscopy reveals a band shift in the hydroxyl peak to higher wavenumbers in Nafion ®/PVA blends (25–90 wt% PVA) with increasing annealing temperature suggesting an increase in the interaction between the hydroxyl groups in PVA and the sulfonic acid groups in Nafion ®. For Nafion ® alone, proton and methanol transport rates increased and then decreased with increasing annealing temperature with a maximum at 210 °C for both solution-cast and as-received (extruded) Nafion ®. This trend coincides with two transition temperatures observed by other investigators using differential scanning calorimetry, suggesting that transport properties are affected by morphological changes in Nafion ®.

Addition of methacryloil groups to poly(vinyl alcohol) in DMSO catalyzed by TEMED: Optimization through response surface methodology

The addition of methacryloil groups from glycidyl methacrylate (GMA) to poly(vinyl alcohol), PVA, was investigated in the former paper of this series. In this report, this reaction was optimized by response surface methodology (RSM). In the first step, the main and the interaction effects of reaction time, temperature, and environment (either room atmosphere or N 2 bubbling) on the degree of substitution (DS) were investigated through a 2 3 factorial design and by keeping the feed solution molar ratio [–OH(PVA)/GMA] equal to 1/0.05. DS was calculated from the respective 1H NMR spectrum. The results showed that the reaction time and temperature inputs are significant ( P<0.05) for the incorporation of methacryloil groups into PVA chains. In the second step, maximum DS was achieved by the use of RSM at 62 °C and reaction time of 6 h. In these optimized conditions, molar ratios [–OH(PVA)/GMA] equal to 1/0.10, 1/0.25, 1/0.50, 1/0.75, and 1/1 were investigated and the respective yield ranged from 91 to 93% when DS was up to 25 mol%. It is difficult to obtain more than 50 mol% substitution of PVA hydroxyl by methacryloil groups even in these optimized conditions due to increased steric hindrance by the large number of the methacryloil groups inserted into PVA. The response surface was based on the model DS = − 19.70 + 6.09 × 10 − 1 T + 1.93 t − 3.89 × 10 − 3 T 2 − 5.21 × 10 − 2 t 2 − 2.14 × 10 − 2 T ∗ t , where T is the temperature (°C) and t the reaction time (hours). This model explained 99.2 of the 99.6% explainable statistical data.

Miscibility and interactions in poly(n-propyl methacrylate)/poly(vinyl alcohol) blends

Poly(n-propyl methacrylate) (PPMA) is miscible with poly(vinyl alcohol) (PVA) over the whole composition range as shown by the existence of a single glass transition temperature in each blend. The interaction between PPMA and PVA was examined by Fourier transform infrared spectroscopy and solid-state nuclear magnetic resonance spectroscopy. The interactions mainly involve the hydroxyl groups of PVA and the carbonyl groups of PPMA. The measurements of proton spin–lattice relaxation time reveal that PPMA and PVA do not mix intimately on a scale of 1–3nm, but are miscible on a scale of 20–30nm. A small negative interaction parameter value has been obtained by melting point depression measurement.

Morphology–rheology relationship in hyaluronate/poly(vinyl alcohol)/borax polymer blends

In this work, we have prepared bioartificial polymer blends using hyaluronate (HA) as a biological component and poly(vinyl alcohol)–borax association (PVAs) as a synthetic component, and investigated the rheological properties as well as morphology of the blends. When plotted against the blend composition, the rheological properties showed both positive and negative deviation from the linear additive mixing rule depending on thermal history. The blend showed enhanced viscosity at the composition of 20 wt% of HA and 80 wt% of PVAs, when PVA was dissolved at high temperature. The viscosity enhancement was caused by the network formation of HA aggregates in the micrometer scale. In addition, the network structure of HA aggregates was found to be fractal with the fractal dimension of 1.7. As PVA system also forms a network structure in the nanometer scale between hydroxyl groups of PVA and borate anions, the blend system is unique in that it has network structures in both micrometer and nanometer scales in one material. On the contrary, HA formed aggregates but not any network structure in the blend of the same composition but of the negative deviation. In conclusion, we showed that HA/PVAs blend system may have diverse morphology as well as very broad spectrum of rheological properties, and could suggest that the rheology and morphology of HA/PVAs blends can be designed not only by controlling composition but also by controlling thermal and deformation history of the components.

Controlled release of heparin from polypyrrole‐poly(vinyl alcohol) assembly by electrical stimulation

A surface modification technique was developed for the covalent immobilization of poly(vinyl alcohol) (PVA)-heparin hydrogel onto electrically conductive polypyrrole (PPY) film with the objective of achieving controlled release of heparin. First, aldehyde groups were introduced onto PPY film through poly(ethylene glycol) monomethacrylate graft copolymerization and subsequent oxidation in acetic anhydride and dimethyl sulfoxide mixture. Then, the prepared PVA-heparin hydrogel was cast onto the PPY film and covalently immobilized to the film through the reaction between the aldehyde groups on the PPY film and the hydroxyl groups of PVA. X-ray photoelectron spectroscopy was used to characterize the surface-modified film after each stage. The strong attachment of the PVA-heparin layer on the PPY film was confirmed by peel test and scanning electron microscopy. The release behavior of heparin from the substrate with and without electrical stimulation was studied and the experimental results showed that the heparin release rate from the prepared substrate using an electric current of 3.5 mA is twofold higher than that without current.

Proton-conducting membranes with high selectivity from phosphotungstic acid-doped poly(vinyl alcohol) for DMFC applications

Proton-conducting hybrid membranes composed of poly(vinyl alcohol) (PVA) and phosphotungstic acid (PWA) were prepared by solution-blending. The effect of PWA doping on the membrane properties such as water uptake, ion-exchange capacity (IEC), proton conductivity and methanol permeability was investigated. Up to 20 wt.% PWA content, both water uptake and methanol permeability slightly increased then decreased continuously until 90 wt.%. Fourier transform infrared spectra indicate that significant amount of PWA was maintained in the polymer matrix even after several hours of immersion in water. Combining FTIR results and the similarity in water uptake and methanol permeability of PVA/PWA hybrid membranes suggests that the variations in associated properties are ascribed to intermolecular hydrogen bonding interaction between hydroxyl groups of PVA and PWA. Methanol permeabilities of hybrid membranes were significantly lower than that of Nafion115. The proton conductivity of hybrid membranes was in the order of 10 −4 S cm −1 and generally increases with PWA content. Finally, the possibility of PVA/PWA hybrid membranes for use in PEMFC was explored. In H 2/O 2 mode, the performance increases with PWA content and a maximum current density of 46 mA cm −2 was obtained with PVA 20 wt.% and PWA 80 wt.% (PVA20PWA80) sample. Performance of DMFC with PVA20PWA80 increases with temperature and reached to 80 mA cm −2 at 80 °C.

Characterization of strong polyelectrolyte hydrogels based on poly(vinyl alcohol)

AbstractMaleic anhydride (MA) was grafted onto both partially and fully hydrolyzed poly(vinyl alcohol) (PVA) in the presence of an initiator. Strong polyelectrolyte polymers were prepared by sulfonation of PVA–MA grafts. The sulfonation was completed by reaction of hydroxyl groups of PVA–MA grafts with two different sulfonating reagents (chlorosulfonic acid and pyridine sulfonic acid). The sulfonation degree was evaluated by acid–base titration and 1H NMR analysis. The solution behaviour of the prepared grafts was evaluated from viscosity measurements. Four kinds of water‐insoluble PVA–MA and PVA–MA‐SO3H hydrogels were prepared by heat treatment, physical gelation and chemical crosslinking with different weight ratios of N,N‐methylene bisacrylamide (MBA) crosslinker. The swelling parameters were measured for all prepared gels in deionized water and aqueous solutions at different pH values from 2 to 12 having constant ionic strength (I = 0.1). All gels exhibit a different swelling behaviour upon environmental pH changes. Copyright © 2004 Society of Chemical Industry

Poly(vinyl alcohol) hydrogel fixation on poly(ethylene terephthalate) surface for biomedical application

A surface modification technique was developed for the covalent immobilization of poly(vinyl alcohol) (PVA) hydrogel onto poly(ethylene terephthalate) (PET) to improve the biocompatibility of the film. The PET film was first graft copolymerized with poly(ethylene glycol) monomethacrylate (PEGMA) in the presence of ethylene glycol dimethacrylate (EGDMA) as crosslinker, and then oxidized with a mixture of acetic anhydride (Ac 2O) and dimethyl sulfoxide (DMSO) to produce aldehyde groups on the PET surface. Finally, the prepared PVA solution was cast onto the film and covalently immobilized on the film through the reaction between the aldehyde groups on the PET film and the hydroxyl groups of PVA. The good attachment of the PVA layer to the PET film was confirmed by observing the cross-section of the PET-PVA film using scanning electron microscopy (SEM). Heparin was immobilized on the PVA layered PET using two different methods, physical entrapment and covalent bonding, to further improve the biocompatibility of the film. Attenuated total reflectance (ATR) FT-IR spectroscopy and X-ray photoelectron spectroscopy (XPS) were used to characterize the chemical composition of the surface modified films. The biocompatibility of the various surface modified PET films was evaluated using plasma recalcification time (PRT) and platelet adhesion.

Evaluation of chitosan/PVA blended hydrogel membranes

Blended membranes of chitosan and poly(vinyl alcohol) (PVA) in various ratios were prepared and treated with formaldehyde. Electron spectroscopy for chemical analysis of the membrane showed that the NH 2 group in chitosan changed into NC group after membrane treatment with formaldehyde. From the spectral change of FTIR, the hydroxyl groups disappeared and an acetal ring and ether linkage were formed for the reaction between the hydroxyl groups of PVA and formaldehyde. The results of differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA) showed that (1) the crystalline area in PVA decreased after treatment with formaldehyde, (2) chitosan and PVA are not very compatible in the chitosan/PVA blended hydrogel membrane and (3) the thermostability of the membranes is enhanced by formaldehyde as crosslink agent. The effect of chitosan content on the water content and water vapor transmission rates on the blended hydrogel membrane were determined. It was found that the water content and water vapor transmission rates on the blended hydrogel membrane increased with increasing chitosan content. In antibacterial assessment, it appears that the antibacterial activity of all chitosan/PVA blended hydrogel membranes is similar. The viable cell number of aurococcus on the various chitosan/PVA blended hydrogel membranes was about (2.5±0.5)×10 7 cells/ml. The permeation of creatinine, 5-FU, uric acid and vitamin B 12 through the chitosan/PVA blended hydrogel membranes were conducted. The linear relationship between permeability of creatinine, 5-FU and vitamin B 12 molecules and chitosan content in the chitosan/PVA blended hydrogel membranes were found. As the electrostatic attraction between the uric acid and chitosan in the membrane, the permeation of uric acid through the chitosan/PVA blended hydrogel membranes is higher for the membranes with chitosan content higher than 80% in the blended hydrogel membranes.