• Bulletin of the Korean Chemical Society
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• v.30 no.11
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• pp.2701-2706
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• 2009

The polymer blends containing polypyrrole (PPy) and the sulphonic acids such as β-naphthalene sulfonic acid (NSA), camphor sulfonic acid (CSA), and dodecylbenzenesulfonic acid (DBSA) were synthesized by in situ deposition technique in an aqueous media using ammonium per sulfate (APS) as an initiator. The obtained films were characterized by scanning electron microscopy (SEM), and the thermal behavior of these polymer blends was analyzed by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The temperature-dependent (DC) conductivity of the obtained films shows a semiconducting behavior with a negative temperature coefficient of resistivity (TCR). The conductivity data were also analyzed through Mott’s equation, which provides the variable range hopping model in three dimensions. The parameters such as density of states at the Fermi energy, hopping energy, and hopping distance were calculated for PPy, PPy-NSA, PPy-CSA, and PPy-DBSA films, and the data were compared.

• Macromolecular Research
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• v.12 no.3
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• pp.303-310
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• 2004

We have prepared an aqueous dispersion of poly(aniline-dodecyl benzene sulfonic acid complex) (PANI-DC) that has an intrinsic viscosity (〔η〕) near 1.3 dL/g using aniline as a monomer, dodecyl benzene sulfonic acid(DBSA) as a dopant/emulsifier, and ammonium peroxodisulfate(APS) as an oxidant. We found that the electrical conductivity of a PANI-DC pellet was 0.7 S/cm. A waterborne-polyurethane (WBPU) dispersion, obtained from isophorone diisocyanate/polytetramethylene oxide glycol/dimethylol propionic acid/ethylene diamine/triethylene amine, was used as a matrix polymer. We prepared blend films of WBPU/PANI-DC with variable weight ratios (from 99/1 to 66/34) by solution blending/casting and investigated the effects that the PANI-DC content has on the mechanical and dynamic mechanical properties, hardness, electrical conductivity, and antistaticity of these films. The tensile strength, percentage of elongation, and hardness of WBPU/PANI-DC blend films all decreased markedly upon increasing the PANI-DC content. The antistatic half-life time ($\tau$$\sub$$\frac{1}{2}$/) of pure WBPU film was about 110 s, but we found that those of WBPU/ultrasound-treated PANI-DC blend films decreased exponentially from 1.2 s to 0.1 s to almost 0 s upon increasing the PANI-DC content from 1 wt% to 15 wt% to > 15 wt%, respectively.

• Archives of Pharmacal Research
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• v.6 no.2
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• pp.109-114
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• 1983

A mechanism of taurine transfer across the rat small intestine was elucidated by using the in situ recirculation perfusion or loop method. Taurine uptake was saturable, Km= 39.9 mM, and energy dependent, and required sodium. The close structural analogues, aminomethane sulfonic acid, .gamma.-amino-butyric acid, hypotaurine, and .betha.-alanine, reduced significantly taurine uptake when present in 10-fold excess. The .alpha.-amino acid, glycine, did not inhibit uptake. Hence, all of these findings lead to a conclusion that a carrier-mediated transport system for taurine exists in the small intestine.

• 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.28 no.3
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• pp.180-186
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• 2018

The nano-composite membranes were prepared onto the polyvinylidene fluoride (PVDF) hollow fiber membranes through twice dip-coating known layer-by-layer method. For the first coating, poly(vinylsulfonic acid, sodium salt)(PVSA) and Poly(styrene sulfonic acid)(PSSA) were used with varying the concentration and ionic strength (IS) and the poly(ethyleneimine)(PEI) as the second coating material was fixed at 10,000 ppm and IS = 0.3. To characterize the prepared nano-composite membranes, the permeabilities and rejection ratio were measured for each 100 ppm NaCl, $CaSO_4$, $MgCl_2$, and 25 ppm MO aqueous solution. The rejections were increased as the concentrations of coating materials increased. And it was confirmed that the salt rejections for PSSA as the coating material were higher than for PVSA. Typically, the permeability, 1.848 LMH and the rejection for MO 76.3% were obtained at the coating conditions of PSSA 30,000 ppm and I.S = 1.0.

• Membrane Journal
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• v.28 no.5
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• pp.332-339
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• 2018

In order to investigate the effect of ion exchange capacity of ion exchange membranes on the salt removal efficiency in the membrane capacitive deionization process, sulfosuccinic acid (SSA) as the cross linking agent was added to poly(vinyl alcohol)(PVA) and sulfonic acid-co-maleic acid (PSSA_MA) was put into PVA at different concentrations of 10, 50 and 90 wt% relative to PVA. As the content of PSSA_MA increased, the water content and ion exchange capacity increased and the salt removal efficiency was also increased in the membrane capacitive deionization process. The highest salt removal efficiency was 65.5% at 100 mg/L NaCl feed at a flow rate, 15 mL/min and adsorption, 1.4 V/5 min for PSSA_MA 90 wt%.

• Journal of Applied Biological Chemistry
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• v.61 no.2
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• pp.191-194
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• 2018

Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) are emerging pollutants in agricultural product, and the residual patterns and the uptake potentials were only studied on several crops, not on rice. The residue level and bioconcentration factor (BCF) of PFOA and PFOS were investigated on the low ($1mg\;kg^{-1}$) and the high contaminated soil ($5mg\;kg^{-1}$) groups. The residue levels in brown rice in the low group and in the high group were 0.002-0.004 and $0.008-0.030mg\;kg^{-1}$ of the each perfluorinated compounds (PFCs), and in the rice husk were $0.035-0.074mg\;kg^{-1}$ and $0.125-0.376mg\;kg^{-1}$ of the each PFCs, respectively. Furthermore, the residues in rice straw were the highest level in the all rice parts both in the groups. The PFOA and PFOS were reached to $3.723mg\;kg^{-1}$ and $7.641mg\;kg^{-1}$, respectively, and the BCF (1.474 and 4.700) as well.

• Proceedings of the Korean Nuclear Society Conference
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• 1998.10a
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• pp.279-279
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• 1998

• Bulletin of the Korean Chemical Society
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• v.24 no.7
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• pp.1041-1044
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• 2003

• Proceedings of the Membrane Society of Korea Conference
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• 2004.11a
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• pp.156-159
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• 2004