• Archives of Pharmacal Research
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• v.28 no.4
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• pp.502-508
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• 2005

Titrated extract of Centella asiatica (TECA) contains three principal ingredients, asiaticoside (AS), asiatic acid (AA), and madecassic acid (MA). These components are known to be clinically effective on systemic scleroderma, abnormal scar formation, and keloids. However, one problem associated with administration of TECA is its low solubility in aqueous as well as oil medium. In this study, various nonionic surfactants and bile salts as anionic surfactant were tested and screened for solubilizing TECA with a view to developing topical hydrogel type of ointment which is stable physicochemically, and has better pharmacological effects. When TECA was incorporated into various nonionic surfactant systems, labrasol had the most potent capacity for solubilizing TECA. In cases of bile salt systems, Na-deoxycholate (Na-DOC) had foremost solubilizing capacity, even more than labrasol. In differential scanning calorimetric study, the peaks of AA, MA, AS and Na-DOC disappeared at the coprecipitate of $1\%$ TECA and $1\%$ Na-DOC, suggesting the optimum condition of Na-DOC for solubilizing TECA. When the physicochemical stability of hydrogel containing this mixture was assessed, it was stable at room temperature for at least one month. Pharmacologically it significantly decreased the size of wound area at the $9^{th}$ day when applied to the wound area of rat dorsal skin. Taken together, solubility of TECA was dramatically improved by using non ionic and anionic surfactant systems, and Na-DOC was found to be the most effective solubilizer of TECA in formulating a TECA-containing hydrogel typed ointment. Moreover this gel was considered to be applicable to clinical use for wound healing effect.

• Journal of the Korean Society of Clothing and Textiles
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• v.23 no.7
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• pp.1030-1039
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• 1999

The effect of surfactant mixture 9on detergency and soil redeposition in a dry-cleaning system was investigated employing Aerosol OT as an anionic surfactant and Span 80 as a nonionic surfactant. The effect of charge system on soil deposition was also investigated in order to determine the optimum condition at which soil redeposition is minimum,. Soil deposition instead of soil redeposition on cotton, polyester and wool fabrics was measured employing petroleum solvent and perchloroethylene as organic solvents. The results were as follows. 1. Surface tension or interfacial tension was not changed by the addition of any surfactant or surfactant mixtures. In petroleum solvent however interfacial tension between solrent and water decreased when surfactants were added and increased when surfactants were mixed,. 2. The maximum amount of water solubilization increased as the mole fraction of Aerosol OT increased and more water was solubilized in petroleum solvent than in perchloroethylene. 3. The detergency of cotton was greater and the soil deposition rate was lower in Span 80 solution than in Aerosol OT solution. The soil deposition on cotton fabric decreased when water was solubilized in Aersol OT solution 4. The detergency and soil deposition rate of polyester fabric did not change by the surfactant type of the addition of surfactant mixture and soil deposition rate increased bywater solubilization. 5. Soil deposition on wool fabric was very high when Arosol OT was employed in perchloroethylene and the soil deposition did not change greatly by water solubilization.

• Journal of Environmental Science International
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• v.5 no.3
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• pp.369-376
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• 1996

The adsorption of the anionic surfactants, sodium lauryl sulfate (SLS) and sodium dodecylbenzene sulfonate (SDBS) anion surfactants form aqueous solutions with nonionic resins, Amberlite XAD-2, XAD-4 and XAD-7 at temperatures in 15~45$^{\circ}C$ range was studied. Several adsorption isotherm models were used to fit the experimental data, The best results were obtained with the Redlich-Peterson equation and the Freundlich model provided remarkably good fits. For a particular resin at a particular temperature, SDBS was more extensively adsorbed than SLS. The highest adsorption were obtained with XAD-4 resin and the specific surface area of the resins plays a major role in adsorption of the surfactants. Estimations of the isosteric heat of adsorption were indicative of an exothermic process, and their magnitudes manifested a physisorption process.

• Macromolecular Research
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• v.17 no.12
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• pp.943-949
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• 2009

A highly dispersed W/O emulsion of silicone oil (cyclomethicone)/water system was prepared with a nonionic surfactant. The surface and interfacial tension between the oil and water were characterized in terms of the droplet size distribution and viscosity change of the emulsion. When the dispersed phase concentration was relatively high, the viscosity of the emulsion was rapidly increased and the droplet size of the emulsion was decreased. The rheological behavior of the emulsion system showed non-Newtonian and shear thinning phenomena depending upon the content of the dispersed phase. The droplet size of the emulsion was decreased with increasing surfactant content and water concentration. The relative viscosity of the emulsion was better predicted with the Choi-Schowalter model than with the Taylor model. The value of the complex modulus increased with increasing surfactant concentration. The linear viscoelastic region was expanded with a dispersed phase concentration. According to the change in the viscosity, the behavior was classified into three distinct regions: [I] linear viscoelastic, [II] partially viscoelastic, and [III] viscous. The creep/recovery behaviors in each region were characterized.

• Clean Technology
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• v.10 no.4
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• pp.221-228
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• 2004

Ethoxylated Nonyl Phenol Series (NP-series), nonionic surfactants, were applied for forming microemulsions in supercritical $CO_2$. Measurement results of the solubility in supercritical $CO_2$ are in the following; NP-series were high soluble in carbon dioxide in spite of the fact that those were not $CO_2$-philic surfactants traditionally well known. Water in $CO_2$ microemulsions were also formed stably. A complexation of hydrophilic lengths for $CO_2$-philic parts of NP-Series surfactants was optimized by NP-4 surfactant(N=4) for forming the microemulsions through the experiments. Formation of microemulsions was confirmed by measuring the UV-Visible spectrum through a spectroscopic method and existence of water in the microemulsions was confirmed as well. In order to apply it for a metal surface treatment or electroplating, an experiment for forming acid(organic, inorganic) solution in $CO_2$ microemulsions was carried out. Ionic surfactant in the reaction to an acid solution became unstable to form microemulsions, however, nonionic surfactant was formed stably in the reaction. Results of the study will be utilized for expanding the application scope of supercritical $CO_2$ which is an environmental-friendly solvent.

• Journal of the Korean Chemical Society
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• v.47 no.6
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• pp.601-607
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• 2003

We studied on preparation of nanoparticles modified surface using biodegradable polymer, poly(DL-lactide-co-glycolide) (PLGA). Two kinds of PLGA nanoparticles were prepared by a spontaneous emulsification solvent diffusion (SESD) method using cetyltrimethylammonium chloride (CTAC) and tetradecyltrimethylammonium bromide (TTAB) as a cationic surfactant and polyethylene glycol-block-polypropylene glycol copolymer (Lutrol F68) as a nonionic surfactant. Model protein was coated on the surface of nanoparticles by the ionic complexation. The model protein was that influenza vaccine ($H_3N_2,\;H_1N_1$, B strain) labeled with NHS-fluorescein. The sizes of cationic nanoparticles were 140-160 nm and the surface charges were 50-60 mV. The sizes of nonionic nanoprticles were 80-90 nm and the surface charge was -10 mV. After coating vaccine on the surface of nanoparticles, the sizes of cationic nanoparticles were increased to 380-400 nm and the size of nonionic nanoparticles was not increased. The amount of coated vaccine on the cationic nanoparticles was 22.73 ${\mu}g$/mg.

• Journal of the Korean Applied Science and Technology
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• v.30 no.4
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• pp.679-687
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• 2013

The critical micelle concentration (CMC) and counter-ion binding constant (B) of the pure cationic surfactants (DTAB, TTAB, CTAB), nonionic surfactants (Tween-20, Tween-40, Tween-80), and their mixed surfactants (TTAB/Tween-20, TTAB/Tween-40, TTAB/Tween-80) in aqueous solutions of 4-chlorobenzoic acid were determined by using the UV/Vis absorbance method and the conductivity method from 284 K to 312 K. Thermodynamic parameters (${\Delta}G^o{_m}$, ${\Delta}H^o{_m}$, and ${\Delta}S^o{_m}$), associated with the micelle formation of those surfactant systems, have been estimated from the dependence of CMC and B values on the temperature and carbon length of surfactant molecules. The calculated values of ${\Delta}G^o{_m}$ are all negative within the measured range but the values of ${\Delta}H^o{_m}$ and ${\Delta}S^o{_m}$ are positive or negative, depending on the length of the carbon chain and surfactant.

• Journal of the Korean Applied Science and Technology
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• v.31 no.2
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• pp.244-254
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• 2014

The interactions of 4-chlorobenzoic acid with the micellar system of various cationic, nonionic, and mixed surfactant systems were studied by the UV/Vis spectrophotometric method. The solubilization constants ($K_s$) of 4-chlorobenzoic acid into those micellar systems have been measured at various temperatures and various thermodynamic parameters for the solubilization of 4-chlorobenzoic acid have been calculated and analyzed from those changes. The results show that the values of ${\Delta}G^o_s$ are all negative within the measured temperature range and that the values of ${\Delta}H^o_s$ and ${\Delta}S^o_s$ are all positive. The effects of alkyl-group's length of surfactant molecules on the solubilization of 4-chlorobenzoic acid have been also measured. The values of $K_s$ were dependent simultaneously on the alkyl-group's length and the kind of head-group in surfactant molecules. From these changes we can postulate the solubilization site and the degree of interaction of 4-chlorobenzoic acid with the micellar systems.

• Journal of the Korean Society of Clothing and Textiles
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• v.29 no.12 s.148
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• pp.1546-1553
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• 2005

The wetting behavior and liquid transport of nonionic surfactant solutions; Span 20 and Tween 20, 40, 60, 80, 21, 61, 81, 65 & 85: in polyethylene terephthalate(PET) fabrics are reported. Five different PET fabrics are used in this study. PET 1, 2 & 3 have different compactness in structure. PET 4 & 5 have similar physical properties to PET 2, however, PET 4 has heat set finish and PET 5 with rewetting agent. The wetting and water retention properties of PET fabrics are greatly improved by addition of nonionic surfactants. The aqueous liquid retention(W) vs. cosq and W vs. adhesion tension has positive linear relationship. Hydrophilic surfactants which have short hydrophobes and surfactants with unsaturated hydrophobe structures are more efffctive in improving the wetting properties of PET fabrics. PET fabric which has larger thread spacing shows greater value of water retention ratio(W/H) than PET fabric with smaller thread spacing if there are no surfactants present in the system, however, W/H values become very similar among these PET fabrics when the surfactants are added. If there are no surfactants present in the system, PET with heat set finish has smaller value and PET with rewetting agent has greater value of W/H than PET without finish even though the fabrics have the similar physical properties.

• Applied Chemistry for Engineering
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• v.16 no.5
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• pp.705-711
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• 2005

The reaction of lauric acid vinyl ester with n-butanol was established to give lauric acid butyl ester by subtilisin A-catalyzed transesterification in organic media containing nonionic surfactants. Pyridine has been used as an organic solvent since it provides higher yields than other organic solvents. However, because of stench of pyridine, compounds enzymatically synthesized in pyridine may be unsuitable as ingredients for foods and drugs. Hence, in order to select an organic solvent to replace pyridine, sugar esters were synthesized with the protease in various organic media. However, no solvent paralleled pyridine in yields. On the basis of this result, pyridine-based W/O microemulsions containing nonionic surfactants and water were used in enzymatic synthesis of the sugar ester, and when Tween 60, Brij 56, or 1-O-octyl-${\beta}$-D-glucopyranose was used for the W/O microemulsions, the yield was higher.