• Polymer(Korea)
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• v.35 no.5
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• pp.438-443
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• 2011

In order to enhance water permeability through the improvement of fouling phenomena and wettability of hydrophobic porous membranes, various adsorption materials, i.e., poly(vinyl amine), poly (styrene sulfonic acid), poly(vinyl sulfonic acid), and poly(acrylamide-co-acrylic acid) were adsorbed onto the surface of polyethylene (PE) porous membrane. The concentration of adsorption solutions, adsorption time, the sort of salts and their ionic strength were varied, and the pure water permeability of their resulting adsorbed membranes was measured. In general, water permeability increased with an initial increase in the concentration of adsorption solution, adsorption time, and ionic strength and then decreased with a further increase. The pure water permeability of 375 $L/m^2h$(LMH), 35% enhancement, was obtained at a condition of poly(vinyl sulfonic acid) 1000 ppm, $Mg(NO_3)_2$ ionic strength(IS) 0.1, and adsorption time 150 sec, while the 50% (411 LMH) and 35% (374 LMH) enhancements were obtained at conditions of poly(styrene sulfonic acid) 1000 ppm, adsorption time 60 sec, and NaCl IS 0.1 and 0.2, respectively.

• Membrane Journal
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• v.21 no.1
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• pp.39-45
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• 2011

An amphiphilic graft copolymer consisting of a poly(vinyl chloride) (PVC) backbone and poly(styrene sulfonic acid) (PSSA) side chains (PVC-g-PSSA) was synthesized via atom transfer radical polymerization (ATRP). This polymer electrolyte membrane was ion-exchanged to Ag ions by immersing in 10 wt% $AgNO_3$ aqueous solution and templated the growth of Ag nanoparticles by a reducing agent. The formation of Ag nanoparticles was confirmed using UV-visible spectroscopy and X-ray diffraction (XRD). Transmission electron microscopy (TEM) revealed that utilization of $NaBH_4$ was the most effective in the formation of Ag nanoparticles with 10~15 nm in size. The formation of Ag nanoparticles was also strongly affected by the concentration of reducing agent and reduction time.

• 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.20 no.1
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• pp.1-7
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• 2010

A graft copolymer, i.e. poly(vinylidene fluoride-co-chlorotrifluoroethylene )-g-poly(styrene sulfonic acid) (P(VDF-co-CTFE)-g-PSSA) with 47 wt% of PSSA was synthesized via atom transfer radical polymerization (ATRP). This copolymer was combined with titanium isopropoxide (TTIP) to produce graft copolymer/$TiO_2$ nanocomposite membranes via sol-gel process. $TiO_2$ precursor (TTIP) was selectively incorporated into the hydrophilic PSSA domains of the graft copolymer and grown to form $TiO_2$ nanoparticles, as confirmed by FT-IR and UV-visible spectroscopy. Water uptake and ion exchange capacity (IEC) decreased with TTIP contents due to the decrease in number of sulfonic acid in the membranes. At 5 wt% of TTIP, the mechanical properties of membranes increased while maintaining the proton conductivity.

• 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.

• Proceedings of the Korean Fiber Society Conference
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• 2003.10b
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• pp.34-37
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• 2003

The development and improvement of advanced fuel cell systems is a major topic of current research, since fuel cells are considerably more efficient than other energy converters$^1$. In proton exchange membrane fuel cell and direct methanol fuel cell the polymer membrane represents a key component. The membrane materials fulfill complex requirements. It has to combine electrochemical stability, workability, high ionic conductivity, low permeation of the reactants (methanol etc.) (omitted)

• 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.