• Applied Chemistry for Engineering
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• v.10 no.4
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• pp.628-634
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• 1999

The orientational binding of ${\omega}$-phenylakylammonium ions to the sodium dodecyl (SDS) micellar interface has been studied from $^{1}H\;NMR$ chemical shift data. The NMR resonaces of the methylene protons of SDS and aromatic protons embedded into the micellar interior have shown the upfield shift. The aromatic induced chemical shifts of the alkyl chain methylene protons of SDS demonstrate the deep penetration into the palisade layer by these organic salts. Alkylammonium groups have been considered to be oriented toward outside of the micellar interface. Aromatic rings have been thought to be oriented toward the micellar core. The depth of penetration by organic salts has been observed to increase with the length of alkyl chain.

• Resources Recycling
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• v.14 no.6 s.68
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• pp.21-27
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• 2005

As one of the hydrometallurgical processes available in the recycling of silver-bearing wastes, the preparation of Ag nano-powder was investigated by a reductive precipitation reaction in silver solution using sodium formaldehydesulfoxylate and ascorbic acid as a reducing agent. Silver solution was prepared by dissolving silver nitrate with distilled water, and Tamol NN8906, PVP, SDS and caprylic acid were also used respectively as the dispersant to avoid the agglomeration of particles during the reductive reaction. Ag particles obtained from the reduction reaction from silver solution were characterized using the particle size analyzer and TEM to determine the particle size distribution and morphology. It was found that about $40\%$ excess of sodium formaldehydesulfoxylate was required to reduce completely silver ions in the solution. It alto appeared that the particle size generated with sodium formaldehydesulfoxylate was much greater than that with ascorbic acid. As far as the effect of dispersant on the Ag particles was concerned, the particle size distribution showed typically bimodal distribution in case of Tamol/FVP while very broad distribution ranged from 0.01 to $100{\mu}m$ appeared in case of SDS/caprylic acid.

• Polymer(Korea)
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• v.28 no.2
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• pp.111-120
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• 2004

The interaction between poly(diallyldimethylammonium chloride) (PDADMAC) of positive charge per repeating unit and anionic surfactant, sodium dodecyl sulfate (SDS) has been investigated by light scattering, turbidimetry and fluorescence. Chain behavior of PDADMAC in 0.3 M NaCl aqueous solution seems like neutral polymer chain In good solvent. By adding SDS into PDADMAC solution, strong attractive interaction develops between them, and can be described with two kinds of critical aggregation concentration(CAC). First, at [SDS]/]DADMAC] 0.06, intramolecular critical micellization of SDS occurs inside a single polymer chain. The maximum size of SDS-polymer complex is observed just before intramolecular CAC. Above intramolecular CAC, the size of this complex starts to shrink slowly due to involvement of polymer subchain in micelle. Second, intermolecular CAC is also observed at [SDS]/[DADMAC] 0.5 by means of turbidimetry. Strong aggregation of polymer chains decorated with many micelles occurs after the second CAC, and huge aggregates have formed.

• Journal of the Korean Chemical Society
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• v.41 no.1
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• pp.12-17
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• 1997

The critical micelle concentrations(CMC*) and the counterion binding constants(B) in a micellar state of the mixed surfactant systems of sodium dodecylsulfate(SDS) with sodium dodecylbenzenesulfonate(DBS) at 25℃ in pure water and in aqueous solutions of n-butanol were determined as a function of α1 (the overall mole fraction of SDS) by the use of electric conductivity method. Various thermodynamic parameters(Xi, γi, Ci, aiM, β, ΔHmix and ΔGm0 for the micellization of SDS/DBS mixtures were calculated and analyzed by means of the equations derived from the nonideal mixed micelle model. The effect of n-butanol on the mixed micellization of SDS/DBS mixtures have been measured and analyzed by comparing the values of the thermodynamic parameters in pure water with those in aqueous solutions of n-butanol(0.1 M, 0.2 M, and 0.3 M).

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.10
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• pp.1271-1277
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• 2008

Competitive displacement of methylcellulose (MC) absorbed at the oil-water interface was investigated by interfacial composition, surface shear viscosity, or surface tension measurements. It was found that all emulsifiers could competitively displace the interfacial MC from the oil-water interface but their behaviors were different from each other. With Tween 20 added to MC emulsion (1 wt% MC, 10 wt% n-tetradecane, 20 mM bis-tris, pH 7), MC load was steadily decreased with increasing concentrations of the emulsifier, as confirmed by surface shear viscosity measurements; moreover, there was complete MC displacement from the emulsion droplet surface at high concentration (0.1 wt%). The oil-soluble Span 80 was found to show a synergism with MC at the interface, which resulted in higher MC load at relatively low emulsifier concentrations ($\leq$0.05 wt%). At a higher emulsifier concentration (0.1 wt%) limited MC displacement was observed. These results were well supported by surface shear viscosity measurements. With water-soluble SDS, MC load was decreased with increasing concentrations of the emulsifier. Unlike Tween 20, however, it was found that at high concentrations (> 0.1 wt%), there was still some MC remaining at the droplet surface. Surface tension measurements are suggestive of an interfacial complex between MC and SDS.

• Analytical Science and Technology
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• v.22 no.4
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• pp.307-312
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• 2009

A spectrofluorimetric methods has been developed for the determination of carbaryl in an aqueous solution. The effects of excitation wavelength, concentration of surfactant, concentration of ethanol as cosurfactant and emission wavelength on the fluorescence intensity were investigated to find the optimum experimental conditions to determine carbaryl. The emission intensity of the carbayl was increased with addition of sodium dodecyl sulfate (SDS) as a surfactant. The emission intensity of the carbaryl was further increased with addition of ethanol as a co-surfactant. The optimum conditions were 281 nm for excitation wavelength, $1.0{\times}10^{-2}mol/L$ SDS, 20% (v/v) ethanol and 349 nm for emission wavelength. Under the optimum conditions, the emission intensity increased with the carbaryl concentration in the range of $5{\times}10^{-7}$ to $1.0{\times}10^{-4}mol/L$ with a detection limit ($3{\sigma}$) of $1.1{\times}10^{-8}mol/L$. The resulting correlation coefficient of the working curve was 0.9996.

• Journal of the Korean Applied Science and Technology
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• v.15 no.3
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• pp.55-60
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• 1998

The sodium ${\alpha}-sulfo$ fatty acid vinyl ester oligomers, which are oligomer type surfactants were prepared by polymerization with fatty acid vinyl acetate. The ${\alpha}-sulfonation$ of fatty acid vinyl ester oligomers were carried by direct addition of sulfur trioxide. The dispersing performance of oligomer type anionic surfactants and sodium dodecyl sulfate(SDS) in the aqueous suspension of iron oxide and titanium dioxide particles was evaluated by particle size distribution and zeta-potential measurement. As results, the particles of iron oxide and titanium dioxide were flocculated by addition of small amount of oligomer type anionic surfactants and sodium dodecyl sulfate(SDS), then the flocks redispersed by more addition of oligomer type anionic surfactants and SDS. The flocculation, redispersion process was observed in lower concentration range of oligomer type anionic surfactants than SDS. Especially, the dispersing action of sodium ${\alpha}-sulfo$ palmitic acid vinyl ester oligomer was better than sodium ${\alpha}-sulfo$ lauric acid vinyl ester oligomer.

• Journal of the Korean Chemical Society
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• v.35 no.6
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• pp.612-616
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• 1991

Metachromatic behavior of methylene blue (MB) in solutions of aqueous sodium dodecyl sulfate (SDS), chondroitin sulfate and L-${\alpha}$-lecithin vesicle at $18~52^{\circ}$C has been studied by absorption spectroscopy. MB was clustered in the matrix of the vesicle with high concentration of L-${\alpha}$-lecithin. The metachromasy of MB was found to be independent of phase transition temperature of vesicles. These results suggest that the dyes were aggregated on the hydrophilic surfaces of vesicle. In the vesicular system, the metachromatic effect of MB was dramatically decreased in the presence of hexadecyltrimethylammonium bromide (CTAB) than SDS. It is estimated that the intercalation site of these surfactants on vesicle surfaces was different, that is, the intercalation of CTAB was more effective than that of SDS.

• Journal of the Korean Chemical Society
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• v.38 no.3
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• pp.194-199
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• 1994

The solubilization sites of some phenyl alkanols such as phenol, benzyl alcohol, phenethyl alcohol, 3-phenyl-1-propanol solubilized in 0.2 M aqueous sodium dodecylsulfate micelle solution was studied by two dimensional heteronuclear correlation spectroscopy (2D C-H COSY). The results show more quantitative and clear solubilization sites in the SDS micelle than previous results using $^1H$-NMR spectrum integration. We found that most of the phenyl alkanols penetrate into the core of SDS micelle, and the insertion depth was 6.5∼7.0 methylene units from ${\alpha}$-methylene.

• Analytical Science and Technology
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• v.34 no.6
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• pp.275-283
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• 2021

This study presents the development of cell-based microfluidic chips for the performance of acute eye irritation tests due to chemicals and examined some of their applications. Microfluidic chips were fabricated by photolithography and soft lithography, and they had three compartments with different areas for cell culture. Rabbit corneal epithelial cells were used for the eye irritation test. The death of cells cultured inside the chip was monitored at regular time intervals after treatment with an aqueous solution of chemicals, and the cell death rate constants were calculated based on the viability curve. The performance of the microfluidic chip was verified by examining the effects of cell-cell junctions, cell-substrate adhesion, and initial cell numbers compared to cell death rates. Eye irritation tests were performed at various concentrations of an aqueous solution of sodium dodecyl sulfate (SDS), a standard substance for the eye irritant test. The cells were exposed to the SDS aqueous solution for 300 s, and the resulting eye irritation was assessed by cell viability. Finally, the equation for calculating the toxicity score (TS) was derived based on the weighting factor for each compartment in the chip. The cell-based microfluidic chip developed in this study may be used for eye irritation tests from chemicals used in cosmetics and pharmaceuticals.