• Macromolecular Research
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• v.17 no.9
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• pp.631-637
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• 2009

This study examined the unique self-doping behavior of carboxylated polyaniline (PCA). The self-doped PCA was synthesized using an environmentally benign enzymatic polymerization method with cationic surfactants. XPS showed that HCl-doped PCA contained approximately 34% of protonated amines but self-doped PCA contained 9.6% of the doped form of nitrogen at pH 4. FTIR and elemental analysis showed that although the PCA was doped with the proton of strong acids at low pH via the protonation of amines, the self-doping mechanism of PCA at pH > 4 was mainly due to hydrogen bonding between the carboxylic acid group and amine group.

• YAKHAK HOEJI
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• v.18 no.3
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• pp.183-189
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• 1974

Distribution coefficients between nitrobanzene solution and deionized water, show a straight line when the number of alkyl radicals against the logarithm of distribution coefficient of the salts was plotted. After extracting salts of the indicator and the cationic surfactants with organic solvents, and employing the colorimetric method was used. A calculation method of distribution coefficients of the salts in the organic solvent has been suggested and it could be used for the extraction equilibrium of the primary amine, $CH_{3}(CH_2)_{n}NH_3^+$ secondary amine, $CH_{3}(CH_2)_{n}NH_{2}(CH_3)^+$, tertiary amine $CH_{3}(CH_2)_{n}NH(CH_3)_2^+$ and quaternary ammonium, $CH_{3}(CH_2)_{n}N(CH_3)_3^+$MO$^-$salts, (n=3,5,7,11).

• The Research Journal of the Costume Culture
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• v.10 no.5
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• pp.555-564
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• 2002

The purpose of this research was to analysis compounds of unpleasant odor from the cotton fabrics in dehydration and drying process during washing. The cotton fabrics were treated with various commercial detergents and fabric softener or cationic surfactants such as Cetyltrimethylammonium bromide(CTAB) and Benzalkonium chloride(BC), then dehydrated and dried. The compounds of odor impregnated in fabric were detected by using CC-MS. The results are as follows: The fabrics treated with a powder-type detergent, CTAB and BC gave out compounds unpleasant odor. n-Butyraldehyde and isobutyaldehyde produced during microorganism growth were revealed as source of the compounds of the unpleasant odor. However, no aldehydes were detected from the fabrics treated with commercial fabric softener which seems to act as a deodorizer.

• Bulletin of the Korean Chemical Society
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• v.16 no.10
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• pp.938-945
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• 1995

Hydrolysis of p-nitrophenyl acetate (PNPA) and p-nitrophenyldiphenyl phosphate (PNPDPP) by N-chloro compounds in micellar solution were studied. N,N'-dichloroisocyanuric acid sodium salt (DCI) in cetyltrimethylammonium chloride (CTACl) micellar solution gave pseudo first-order kinetics. But, DCI in cetyltrimethylammonium bromide (CTABr) micellar solution showed typical series first-order kinetics - fast hydrolysis of the esters and concomitant slow decay of the hydrolyzed product, p-nitrophenolate. The hydrolysis rate was decreased as the hydrophobicity of N-chloro compounds was increased, which is the opposite trend to the usual bimolecular micellar reaction. This curious behavior of the N-chloro compounds in the catalytic hydrolysis of PNPA and PNPDPP in a cationic micellar system can be best explained by participation of counter ions of the surfactants during hydrolysis.

• Bulletin of the Korean Chemical Society
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• v.18 no.4
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• pp.379-384
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• 1997

High quality MCM-41 is prepared from a gel of molar composition SiO2:0.20 CTACl:0.18 TMAOH:25 H2O aged at 20 ℃ for 24 hours before crystallization lasting for 48 hours. The (110) and (200) peaks of XRD pattern of high quality MCM-41 are unusually well resolved and the FWHM (full-width-at-half-maximum) of the (100) peak is 0.13° for as-prepared MCM-41 and 0.21° for calcined one, which indicate well-developed crystals. The properties of the crystal depend on the source and concentration of the reactants and the gel aging time. There is no induction period in the course of the synthesis, which is conveniently monitored by pH measurement. Gel aging, during which a spatial distribution of silicate polyanions and micellar cations is established, is essential for preparing high quality MCM-41. Surfactants with the same cationic organic group but different counteranions change the crystallization behavior. Highly basic gel (pH=12.6) favours the lamellar product; the quality of MCM-41 is lower as insufficient TMAOH is available to dissolve the silica.

• Bulletin of the Korean Chemical Society
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• v.8 no.4
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• pp.261-264
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• 1987

Benoxaprofen (2-(4-chlorophenyl)-${\alpha}$ -methyl-5-benzoxazole acetic acid) is a nonsteroidal anti-inflammatory drug that causes acute cutaneous phototoxicity. The ability of benoxaprofen (BXP) and its photoproduct, decarboxybenoxaprofen (DBXP) to photosensitize the decomposition of tryptophan was evaluated in various media such as water, ethanol and aqueous micellar dispersions of surfactants. The weak photosensitization of BXP in water was found to be enhanced in cationic CTAB micelle system, but yielded little difference in anionic SDS micelles. In ethanol solution, BXP was determined to photosensitize the decomposition of tryptophan, but no photosensitization was observed with DBXP. All of these results implicate that the anion radical of BXP may play a major role in the photosensitization in hydrophobic micellar phase, forming superoxide through interaction with oxygen as demonstrated by observation that the photosensitization was inhibited by superoxide dismutase.

• Korean Chemical Engineering Research
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• v.50 no.6
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• pp.960-968
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• 2012

In this study, the measurement of physical properties of 3 different ethylene oxide adducted zwitterionic surfactants were measured such as critical micelle concentration, surface tension, interfacial tension, contact angle, viscosity and foam stability. Also, the dual function characteristics of the zwitterionic surfactants were investigated by determining an isoelectric point, which were obtained using zeta potential measurement and QCM (quartz crystal microbalance) experiments. The isoelectric point of the synthesized zwitterionic surfactant determined by zeta potential measurement was close to that obtained by QCM experiment and both results have shown almost the same trend as that determined by the frictional property measured using an automated mildness tester. In particular, it has been observed that all three surfactants used during this study provide better softening effect at a pH of neutral condition than at an acidic or an alkaline condition. This result indicates that the synthesized surfactants act as a cationic surfactant at a pH of neutral condition and thus provide good softening effect during a rinsing cycle in the detergency process.

• Applied Chemistry for Engineering
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• v.27 no.3
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• pp.291-298
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• 2016

In this study, zwitterionic surfactants were added to liposome systems at different pH conditions to understand the effect of surfactants on liposome characteristics. For this purpose, amine oxide surfactants having different hydrocarbon chain lengths were synthesized and the structure of the resulting product was elucidated by using $^1H$ NMR, $^{13}C$ NMR, and FT-IR. In addition, the physical properties of newly synthesized surfactants such as critical micelle concentration (CMC), surface tension and isoelectric point were measured. The stability characteristics of liposome systems including average particle sizes and zeta potentials were measured by varying pH and hydrocarbon chain lengths of an amine oxide surfactant. Effects of the pH and hydrocarbon chain length of an amine oxide surfactant on fluidity of a liposome membrane were also examined by measuring the deformability and the binding degree between the surfactant and liposome.

• Analytical Science and Technology
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• v.14 no.2
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• pp.167-172
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• 2001

The technique that could collect efficiently the hanji fibrous sludge from wastewater using surfactants was developed. When fibrous sludge of which concentration was about 80mg/L, was floated and collected, the optimum concentration of sodium oleate, the pore size of glass filter and the air flow rate were 10mg/L, $5-10{\mu}m$ and 200mL/min., respectively. The behavior of sodium oleate might be interfered by polyvalent cations such as $Ca^{2+}$. But when the concentration of $Ca^{2+}$ was less than 100mg/L, the interference effect did not appear. And when a typical cationic surfactant, cetyltrimethylammonium bromide(CTAB), was used, the collecting yield was less than that of sodium oleate, and the amount of foam was higher than sodium oleate. When 1mg/L of CTAB was added to the hanji sludge sample contained 1mg/L of $PAMID^{(R)}$, a dispersant, fibrous sludge was effectively coagulated, the flotation time was very short and the collecting yield was above 95%. But in the case, sodium oleate was inefficient.

• Applied Chemistry for Engineering
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• v.9 no.1
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• pp.149-154
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• 1998

The characteristics of drag reduction and rheological behaviors were investigated using cationic surfactants, whose microstructures are known to change when concentration of the surfactant exceeds CMC. The firstly formed spherical micelles change to rodlike or disklike micelles because of packing between surfactants micells, and of thermodynamic perference. The drag reduction becomes significant when the concentration increases over this micellar transient point. Drag reductions were measured as a function of concentration, and rheological characteristics of the surfactant were further investigated to understand the correlation between their rheological properties and drag reduction. Micelles show the non-Newtonian behavior, and shear thickening behaviors were observed due to the structural development. In addition, structural developments were determined by adding the counter-ion in case of DOBON-G.