• Membrane Journal
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• v.17 no.2
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• pp.140-145
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• 2007

In this study, 3-(trihydroxysilyl)-1-propanesulfonic acid (THS-PSA) was added to poly(vinyl alcohol) (PVA) membranes crosslinked with poly(styrene sulfonic acid-co-maleic acid) (PSSA_MA) to improve the separation characteristics toward water vapors in the air. The prepared membranes varying both PSSA_MA and THS-PSA amounts were also synthesized at different cross linking temperatures. Then, in order to investigate the separation characteristics of the resulting membranes, the dynamic vapor sorption (DVS) and vapor permeation experiments were carried out. The increase of cross-linking temperature showed longer time to reach the equilibrium sorption state from the dynamic vapor sorption experiments. PVA/PSSA_MA (3%)/THA-PSA(7%) prepared at $120^{\circ}C$ gave the highest permeability of 480 barrer at $35^{\circ}C$.

• Membrane Journal
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• v.25 no.4
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• pp.327-331
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• 2015

Poly(vinyl alcohol) (PVA) membranes cross-linked with sulfosuccinic acid (SSA) in which poly(4-styrene sulfonic acid-co-maleic acid) (PSSA_MA) was blended to endow more ion exchange capacity were prepared to measure the permselectivities of water-alcohol mixtures by pervaporation separation technique. The feed mixtures of binary aqueous methanol, ethanol and iso-propyl alcohol solution by 90 wt% alcohol portion were used. Typically, for PVA10/SSA9/PSSA_MA90 membrane, the flux of 202.6, 47.8, $20.2g/m^2hr$ for aqueous methanol, ethanol and iso-propyl alcohol solutions was shown while the best separation factors of 34.2, 291 and 991 were given by PVA10/SSA11/PSSA_MA80 membrane. More details are discussed in main text of this article.

• Membrane Journal
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• v.25 no.2
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• pp.144-151
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• 2015

The water-soluble poly(vinyl alcohol) membranes with the addition of sulfosuccinic acid (SSA) were prepared and to assign the ion exchange capacity, poly(4-styrene sulfonic acid-co-maleic acid) (PSSA_MA) was added to PVA according to PSSA_MA contents of 70, 80 and 90 wt%. To characterize the resulting membranes, FT-IR, water contents, ion exchange capacity, proton conductivity and methanol permeability were measured. As PSSA_MA contents increased, water contents, ion exchange capacity, proton conductivity increased, but methanol permeability decreased. From these results, the best preparation component was known as PVA10/SSA9/PSSA_MA80.

• Membrane Journal
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• v.18 no.1
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• pp.44-52
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• 2008

Pervaporation separation for water-ethanol mixtures has been carried out using crosslinked poly(vinyl alcohol) (PVA) membranes with poly(styrene sulfonic acid-co-maleic acid) (PSSA_MA) and at which tetraethylorthosilicate (TEOS) was introduced. The concentration of PSSA_MA was fixed 7 wt% over PVA and the TEOS contents, 3, 5, and 7 wt%, were varied against PVA. The composition of the feed mixtures were 10, 20, 30 and 50 wt% of water in it. PVA/PSSA_MA/5 wt% TEOS membrane showed the separation factor, 1730 and the permeability, $16.3g/m^2{\cdot}hr$ for water : ethanol = 10 : 90 at $50^{\circ}C$.

• Polymer(Korea)
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• v.35 no.4
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• pp.296-301
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• 2011

This study focuses on the investigation of the impregnation of poly (vinyl alcohol) (PVA) crosslinked with poly(styrene sulfonic acid-co-maleic acid) (PSSA-MA) to porous polyethylene membrane for the fuel cell application. The membranes were characterized by the measurements of the water content, contact angle, FTIR spectra, thermal gravimetric analysis, ion exchange capacity, proton conductivity, methanol permeability and elastic modulus. The existence of hydrophilic moieties in the impregnated membranes was confirmed by contact angle and FTIR measurements. The impregnated PVA/PSSAMA(90:10) membrane exhibited a higher ion exchange capacity (1.2 meq./g dry membrane) than Nafion membrane (0.91 meq./g dry membrane). Through the elastic modulus measurement, the dimensional stability of the resulting membranes was expected to increase higher than the polyethylene membranes. The methanol crossover and water content decreased even if the PSSA-MA content increased due to the reduction of the free volume.

• Membrane Journal
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• v.16 no.3
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• pp.235-239
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• 2006

This study illustrated the results of pervaporation separation using crosslinked poly(vinyl alcohol) (PVA) with poly(styrene sulfonic acid-co-maleic acid) (PSSA-MA) for water-ethanol system at 25, 35, and $45^{\circ}C$. The contents of the crosslinking agents were 7, 9, and ll wt% against PVA and the feed compositions of 50, 20, 10 and 4.4% in water were investigated. Typical trends of permeability and separation factor in pervaporation were observed for both the crosslinking agents and operating temperatures. For water : ethanol = 10 : 90, and at $45^{\circ}C$, PSSA-MA 11 wt% membrane showed the permeability $58.92g/m^2{\cdot}hr$ and the separation factor 12003 respectively.

• Membrane and Water Treatment
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• v.7 no.2
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• pp.101-113
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• 2016

In this study, to improve the water flux of porous hydrophobic membranes, various water-soluble polymers including neutral, cationic and anionic polymers were adsorbed using 'salting-out' method. The adsorbed hydrophobic membrane surfaces were characterized mainly via the measurements of contact angles and scanning electron microscopy (SEM) images. To enhance the durability of the modified membranes, the water-soluble polymers such poly(vinyl alcohol) (PVA) were crosslinked with glutaraldehyde (GA) and found to be resistant for more than 2 months in vigorously stirred water. The water flux was much more increased when the ionic polymers used as the coating materials rather than the neutral polymer and in this case, about 70% of $0.31L/m^2{\cdot}h$ (LMH) to 0.50 LMH was increased when 300 mg/L of polyacrylamide (PAAm) was used as the coating agents. Among the cationic coating polymers such as poly(styrene sulfonic acid-co-maleic acid) (PSSA_MA), poly(acrylic acid-comaleic acid) (PAM) and poly(acrylic acid) (PAA), PSSA_MA was found to be the best in terms of contact angle and water flux. In the case of PSSA_MA, the water flux was enhanced about 80%. The low concentration of the coating solution was better to hydrophilize while the high concentration inclined to block the pores on the membrane surfaces. The best coating condition was found: (1) coating concentration 150 to 300 mg/L, (2) ionic strength 0.15, (3) coating time 20 min.

• Membrane Journal
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• v.21 no.3
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• pp.299-305
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• 2011

This study deals with the preparation of polymeric electrolyte membranes having high durability for the application of fuel cells. The membranes under investigation were prepared the impregnation to porous polyethylene membranes with poly(vinyl alcohol)(PVA), poly(styrene sulfonic acid-co-maleic acid), and (PSSA-MA)3-(trihydroxysilyl)-1-propanesulfonic acid (THS-PSA). To characterize the resulting membranes, the water contents, the contact angles, FT-IR, the proton conductivity and the the modulus were measured. The proton conductivity of 30% content of THS-PSA at $55^{\circ}C$ gave excellent $1.27{\times}10^{-1}S/cm$ and the mechanical strength was improved 7 times higher up to the THS-PSA content 15%, as a result, the durability was elevated extensively.

• Membrane Journal
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• v.18 no.4
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• pp.336-344
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• 2008

This manuscript deals with the investigation of the possibility of the crosslinked poly(vinyl alcohol) membranes with both poly(styrene sulfonic acid-co-maleic acid) and 3-(trihydroxysilyl)-1-propanesulfonic acid (THS-PSA) for the fuel cell application. The studies were focused on the characterization of the resulting membranes through water content, thermal gravimetric analysis, ion exchange capacity, ion conductivity and methanol permeability measurements and then compared with the existing Nafion membrane. Typically, the ion conductivity lied in the range of $10^{-3}$ to $10^{-2}\;S/cm$ while the methanol permeability showed the range of $10^{-6}$ to $10^{-8}\;cm^2/s$.

• Membrane Journal
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• v.16 no.2
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• pp.153-158
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• 2006

The crosslinked poly(vinyl alcohol) (PVA) mwmbranes with poly(styrene sulfonic acid-co-maleic acid) (PSSA-MA) were used to measure the water vapor and air permeabilities at 25 and $35^{\circ}C$. In addition, the contact angles of crosslinked PVA membranes were observed and increased with PSSA-MA contents. The water vapor permeability of 15300 Baller (1 Baller=$10^{-10}cm^3(STP){\cdot}cm/cm^2{\cdot}s{\cdot}cmHg$) was shown the maximum value at $35^{\circ}C$ when PSSA-MA=7 wt% membrane was used. The gas permeability of 146 Barrer was indicated the maximum at PSSA-MA=7 wt% at $35^{\circ}C$ and $P(H_2O)/P(Air)$ was the highest value 109.2 at $25^{\circ}C$.