• Journal of Life Science
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• v.20 no.11
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• pp.1611-1616
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• 2010

The purpose of this research was to determine the effect of surfactant micelles on lipid oxidation in W/O/W multiple emulsions. The content of ferric irons and hydroperoxide in the continuous phase in W/O/W multiple emulsions was measured as a function of Brij micelle. The concentration of ferric iron and hydroperoxide in the continuous phase increased with increased storage time (1~6 days). Lipid oxidation rates, as determined by the formation of lipid hydroperoxides, TBARs and headspace hexanal, in the W/O/W multiple emulsions containing ferric iron decreased when 3% surfactant micelles were exceeded. These results indicate that excess surfactant micelles could alter the physical location and prooxidant activity of iron in W/O/W multiple emulsions.

• Archives of Pharmacal Research
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• v.15 no.2
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• pp.126-129
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• 1992

The critical micelle concentrations (CMCs) of aqueous solutions of a nonionic surfactant, polyoxyl 23 lauryl ether in the presence of various concentration of urea and its derivatives were measured. The CMC of the surfactant increase in proportion to the concentration of the additives, and the CMC-raising activities increased with more and longer alkyl grups substituted in urea. The CMC shift values were successfully correlated with the cloud point shift values and the protein-denaturing activities of the additives, respectively. These results suggest that the micelle formation, clouding of the surfactant and the protein denaturation are a closely related phenomenon, and a common mechanism is operating which might be the hydrophobic interaction.

• Korean Journal of Food Science and Technology
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• v.34 no.5
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• pp.770-774
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• 2002

Effect of surfactant micelles on lipid oxidation was determined in soybean oil-in-water (O/W) emulsions. The concentration of ferric irons to continuous phase in the O/W emulsions was measured as a function of various Brij type and concentrations. The concentration of ferric iron in the continuous phase increased with increasing surfactant micelles concentration $(0.5{\sim}2.0%)$ and storage time $(1{\sim}7\;days)$. At pH 3.0, the concentration of continuous phase iron was higher than at pH 7.0. Lipid oxidation rates, as determined by the formation of lipid hydroperoxides and headspace hexanal, in the O/W emulsions containing ferric iron decreased with increasing surfactant micelle concentration $(0.5{\sim}2.0%)$. These results indicate that surfactant micelles concentration could alter the physical location and prooxidant activity of iron in soybean O/W emulsions.

• Journal of the Korean Applied Science and Technology
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• v.18 no.4
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• pp.249-253
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• 2001

A proposed method of determining the composition of mixed micelles in equilibrium with monomer of known composition is described. The systems were sodium ${\alpha}-sulfonated$ dodecanoyl ethyl esther (${\alpha}-SR_{12}Et$) or sodium dodecyl sulfate(SDS)-polyoxyethylene 23 lauryl ether (Brij 35) un water and in 0.1M sodium chloride solution at $25^{\circ}C$. This technique applies the Gibbs-Duhem equation to the mixed micelles, which is treated as a pseudophase. This proposed methodology, which needs only critical micelle concentration data as a function of monomer composition, is applied to an anionic/nonionic surfactant pair. The calculated monomer-micelle equilibrium is found to be very similar to the much-used regular solution for nonideal systems.

• Bulletin of the Korean Chemical Society
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• v.10 no.5
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• pp.437-442
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• 1989

The cmc's of sodium dodecyl sulfate (SDS)/Triton X-100 surfactant mixtures were determined by surface tension measurement at various surfactant compositions. The cmc values were lower than those predicted from ideal mixture. The regular solution theory was applied to calculate the interaction parameter, micellar composition, and the activity coefficients of surfactants in the mixed micelle. The interaction parameter (${\beta}$) was - 2.1. The nonideality arised largely from decreased activity of SDS in the mixed micelle. The mean aggregation numbers (${\bar{n}}$) and micropolarity of hydrocarbon region of the mixed micelles were determined by luminescence probe techniques. The total aggregation number (${\bar{n}}_{SDS}+{\bar{n}}_{TX}$) in mixed micelles showed little dependency on the composition of the micelle. The apparent dielectric constant of the hydrocarbon region of the micelle vs micellar composition plot showed positive deviation from linearity. Emission and emission quenching of excited tris(2,2'-bipyridine)ruthenium(Ⅱ) cation, $(Ru(bpy)_3^{2+})$, by methylviologen ($MV^{2+}$) were also investigated in the mixed micellar solutions. The quenching rate was lowest when the mole fraction of SDS in the surfactant mixtures (${\alpha}_{SDS}$) is about 0.25 and highest at ${\alpha}_{SDS}$ = 0.85. This was explained in terms of combined effects of binding of the cations with the micelle and mobility of the bound cations on the surface of the micelles.

• Journal of the Korean Chemical Society
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• v.33 no.5
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• pp.459-467
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• 1989

When the sufactants are dissolved in water, they associate to form micelles and solubilize oil inside the micelle to form swollen micelles. Although spherical aggregates like micelles and swollen micelles occupy the same regions in the phase diagram of water-oil-surfactant systems, they are treated in different viewpoint for the formation of such aggregates. Hence a unified thermodynamic formalism for the formation of such structure is presented in this study. In all cases, the to ideal solution theory is applied for dilute system and the energy of formation is expressed as the sum of hydrophobic interaction energy and surface energy due to surfactant film. From the model, critical micelle concentration (CMC), average aggregation number, and solubilization ratio are predicted and compared with the known experimental observation.

• Journal of Environmental Science International
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• v.9 no.5
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• pp.403-408
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• 2000

On the basis of theory of Bratsch's electronegativity equalization the electronegativity equalization the group electronegativities and the group partial charges for cationic and amphoteric surface and amphoteric surfactants could be calculated using Pauling's electronegativity parameters. From calculated output we have investigated relationships between CMC(critical micelle concentration) and partial charge and group electronegativity of hydrophilic and hydrophobic groups structural stability of micelle for cationic and amphoteric surfactants. As a result CMC depends upon partial charge and electronegativity of hydrophilic group is decreased. With increasing the carbon number of hydrophilic group for cationic surfactant its partial charge is increased but CMC and its electronegativity are decreased. With increasing the carbon number of hydrophobic group for cationic and amphoteric surfactant its partial charge is increased but CMC andits electronegativity are decreased.

• Applied Biological Chemistry
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• v.47 no.1
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• pp.72-77
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• 2004

The purpose of this research was to determine the effect of phenol compounds from green tea leaves and surfactant micelles on lipid oxidation in com oil-in-water emulsion (O/W). The concentration of phenol and surfactant in continuous phase of the O/W with exceed Brij 700 and phenol compounds was measured. The particle size of O/W with phenol (100 ppm) increased with increasing added exceed surfactant $(0{\sim}2.0%)$ and the concentration of surfactant and phenols in the continuous phase higher than these of control. Lipid oxidation rates, as determined by the formation of lipid hydroperoxides and headspace hexanal, in the O/W emulsions containing phenol compounds (100 ppm) and exceed surfactant $(0{\sim}2.0%)$ decreased with increasing concentration of exceed surfactant. The ability of the phenol compounds and exceed surfactant to inhibit hydroperoxide and headspace hexanal producing as lipid oxidation in O/W was BHT>procyanidin B3-3-O-gallate> (+)-gallocatechin > (+)-catechin and 2% > 1 % > 0% of exceed surfactant. These results indicate that phenol compounds and exceed surfactant could alter the physical location of hydroperoxide in O/W.

• Applied Chemistry for Engineering
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• v.10 no.6
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• pp.876-880
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• 1999

The surfactant self-diffusion coefficients of mixed micellar solutions of ionic and nonionic surfactants have been measured by the NMR pulsed field gradient spin echo(FT-PGSE) method. In addition, the line widths of $^1H$ NMR signal have been monitored. The system investgated are $C_{12}EO_5/SDS/D_2O$, $C_{12}EO_5/DTAC/D_2O$, and $C_{12}EO_8/SDS/D_2O$. In the sample series, the molar ratios of $D_2O$ to surfactant(ionic+nonionic) were kept constant while the surfactant mixing ratio was varied. For the $C_{12}EO_5$ system, the surfactant self-diffusion coefficient indicates minimum when the surfactant mixing ratio is about 20% ionic surfactant. The observed decrease in self-diffusion coefficients as nonionic surfactant was replaced by ionic surfactant is interpreted to mainly be due to an increased micelle-micelle repulsion. The increase in self-diffusion coefficients occurring at higher fraction of ionic surfactant is shown to be due to a decrease in micelle size. For the $C_{12}EO_8$ system, the effect of the surfactant mixing ratio is much weaker which can be understood by considering the molecular geometry and large headgroup area. The proton NMR line widths correlate well with the self-diffusion coefficients and broadening of the alkyl chain methylene signals is found when the self-diffusion coefficients is low.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.09a
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• pp.283-286
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• 2002

Solubilization and partitioning of naphthalene was investigated in an aqueous system containing soils and surfactants. The environmental behavior of polycyclic aromatic hydrocarbons(PAHs) was mainly governed by their solubility and partitioning properties on soil media in a subsurface system. In surfactant-enhanced remediation systems, surfactants might be an additional variable. a natural soil ,silica and kaolinite were tested as soil media. two nonionic surfactants, Triton X-100 and Hydropropy1-$\beta$-cyclodextrin (HPCD) were employed for naphthalene solubilization. Naphthalene showed linear on natural soil while non-linear sorption on silica and kaolinite. Soils have higher sorption capacity for Triton X-100 than HPCD indicating Triton X-100 formed ad-micelle on the soil surface. Desorption study showed a hysterysis and reversible desorption. The partitioning coefficient(K$_{D}$) of naphthalene was increased as the concentration of surfactant was increased. (below CMC), however, the coefficient was decreased above CMC. This indicates that naphthalene is partitioned into the micelles and the partition occurs competitively on both ad-micelle and free micelles as surfactant concentration increases. Therefore, the target compounds to be dissolved into aqueous phase in a surfactant enhanced remediation system might be highly partitioned on to the ad-micelle resulting in an adverse effect rather increased solubilization would be achieved.d.