• Applied Chemistry for Engineering
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• v.7 no.6
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• pp.1142-1146
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• 1996

Cholesterol-containing surfactant was synthesized, and it was sonicated with monomer in water to form a vesicle solution. This vesicle solution was dried to construct a membrane which had a molecular multilayer structure. Using UV irradiation the monomer in this membrane were polymerized, and then surfactant was extracted by organic solvent. Using a X-ray diffractometer, the thickness of one layer and the regularity of the multilayer were measured. And scanning electron microscopy was conducted for fractured polymer film.

• Applied Chemistry for Engineering
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• v.9 no.5
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• pp.763-767
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• 1998

Cholesterol-containing surfactant was synthesized, and it was sonicated with monomer [tetradeca(ethylene glycol) diacrylate] in water to from a vesicle solution. This vesicle solution was dried to construct a membrane which had a molecular multilayer structure. The monomer which stay in this membrane was polymerized with photoinitiation, and then surfactant was extracted by organic solvent. The physical properties of the two dimensional polymer network were measured, and these physical properties are tensile strength, elongation, and swelling.

• Applied Chemistry for Engineering
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• v.19 no.1
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• pp.59-65
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• 2008

The equilibrium solubilization capacity of the mixture of hydrocarbon oils by $C_{12}E_8$ nonionic surfactant micellar solution was measured at $23^{\circ}C$ by gas chromatography (GC) analysis. Experimental results indicated that the solubilization capacity for pure alkanes was found to decrease almost linearly with the alkane carbon number (ACN) of the hydrocarbon oil. For the binary mixture systems of the hydrocarbon oils both selective and nonselective solubilization behaviors were observed depending on the difference in ACN of the two hydrocarbon oils. Equilibrium solubilization tests for the hydrocarbon oil mixtures in $C_{12}E_8$ surfactant solutions such as the three n-octane/n-nonane, n-nonane/n-decane and n-decane/n-undecane mixture systems suggest almost non-selective solubilization. On the other hand, the n-octane/n-decane and n-octane/n-undecane systems, where difference in ACN of the two hydrocarbon oils is greater than 1, selective solubilization in favor of n-octane was conclusively demonstrated.

• Journal of Soil and Groundwater Environment
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• v.13 no.5
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• pp.74-80
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• 2008

Heavy metals, Cd and Pb, in soil were extracted by using anionic surfactants such as AOS (alpha olefin sulfonate), SDS (sodium dodecyl sulfate), and LAS (linear alkyl benzene sulfonic acid). Metal extractability from soil was affected by the carbon number and solution pH of surfactants. LAS showed higher metal extractability due to the acidic solution condition. Although SDS has a fewer carbon number than AOS, it would produce smaller micelles and resulted in more efficient extraction of metals by increased soil contact. Cd extractability of surfactant was twice enhanced by adding NaI as a ligand. However, Pb extractability of surfactant was sometimes reduced by adding NaI. Those ligand effects were dependent on solubility of metal-ligand. The column experiment also showed that SDS having smaller micelles resulted in higher metal extractability than AOS.

• Journal of the Korean Chemical Society
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• v.37 no.6
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• pp.562-569
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• 1993

The pseudophase separation model is used to describe the effects of pH and n-propanol on the mixed micellar formation of protonated and unprotonated dimethyldodecylamine oxides. Dimethyl-dodecylamine oxide surfactant molecules may exist in aqueous solution in either nonionic (unprotonated) or cationic (protonated) form, and they can be modeled thermodynamically as a binary mixture of cationic and nonionic surfactants. The composition of the binary mixture is varied by adjusting the solution pH. And activities, micellar compositions, and monomeric compositions of two surfactant species can be calculated directly from the experimental titration data by applying pseudophase separation model to the micellar system of DDAO in water/n-propanol. The critical micellar concentrations and the p$K_a$ values of the binary mixture systems are dependent on the micellar composition of the protonated cationic surfactant (X); especially they show the minimum phenomena when they are plotted against the micellar composition of the protonated cationic surfactant (X). The critical micellar concentration of the binary mixed DDAO system is generally decreased when n-propanol is added to the binary mixture system, and the degree of decrease is dependent on the concentration of n-propanol.

• Korean Chemical Engineering Research
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• v.45 no.3
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• pp.219-225
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• 2007

The equilibrium solubilization capacity of pure hydrocarbon oils by 2.5 wt% $C_{12}E_8$ nonionic surfactant solution was measured at $30^{\circ}C$ by gas chromatography (GC) analysis. Experimental results indicated that the molar solubilization ratio (MSR) for pure alkanes was found to decrease almost linearly with the alkane carbon number (ACN) of the hydrocarbon oil. For the binary mixture systems of the hydrocarbon oils both selective and nonselective solubilization behaviors were observed depending on the difference in carbon number of the two hydrocarbon oils. Equilibrium solubilization tests for the two n-octane/n-nonane and n-nonane/n-decane mixture systems in $C_{12}E_8$ surfactant solutions suggest slightly selective solubilization in favor of n-octane, but the small difference in solubilization rates between two hydrocarbon oils does not allow ruling out non-selective solubilization for these particular systems. This is certainly not the case for the n-octane/n-decane mixture, for which selective solubilization was conclusively demonstrated by GC analysis data.

• KSBB Journal
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• v.16 no.3
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• pp.241-245
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• 2001

Mass transfer rates have been measured for the extraction of enzyme from aqueous solution into a reverse-micelle phase at $25^{\circ}C$. The 420 mL vessel was carefully designed to maintain a planar interface between the aqueous and solvent phases, so allowing precise measurement of interfacial area, has been investigated. Sodium di-2-ethylhexyl sulfosuccinate(AOT) was the surfactant used. Factors varied included: agitator speed, pH, ionic strength and surfactant concentration. Samples were taken from the solvent phase at 15min intervals, and the amount of enzyme extracted was measured by UV absorption at 280 nm. The observed Sherwood numbers for the aqueous phase $Sh_1$were correlated interms of the aqueous phase Reynolds number $Re_1$, and modified Schmidt number $Sc_1$. $Sh_1=0.664Re_1^{0.5}Sc_1^{0.33}$

• Journal of the Korean Society of Safety
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• v.6 no.3
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• pp.40-49
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• 1991

To better understand the phenomena inside an absorber, where heat and mass transfer coexist, this study selected the most baslc absorption model from in whifh water vapor is absorbed on the surface of a stationary lithium bromide absurbent solution. The purpose of this study is to obtain basic knowledge of heat and mass transfer processes as affected by Marangoni convection induced by addition of surfactant. We apply a non-flowing bulk absorption model and assume that dropwise surfactant is fixed on the absorbent surface. Four governing equation-continuity, laminar monentum, energy and diffusion are solved numerically to obtain temperature and concentraion distributions during steam absorption with Marangonl convection.. In conclusion, Sh and Nu genrally increase at the initial absorption stage.

• Journal of the Korean Applied Science and Technology
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• v.17 no.2
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• pp.99-104
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• 2000

Physical properties and performance characteristics of sodium salt of several pure N-acyl amino acids made from glycine, dl-alanine, sarcosine, dl-valine, l-leucine, l-aspartic acid and l-lysine seven long chain fatty acids are reported. The effect of acyl chain length and the differences in the structure of constituent amino acid of seven homologous series of amide intermediate linked carboxylate surfactant of this class on the properties are discussed.

• Journal of the Korea Institute of Building Construction
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• v.11 no.6
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• pp.557-566
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• 2011

The surfactants facilitate the formation of foam bubbles under a proper condition and provide stability of foam bubbles by decreasing the surface tension of solutions and increasing the viscosity of foam surface. However, there have been almost no practical data of foam concrete in this regard so far. This study aims to understand the effects of foaming agents such as anionic synthetic surfactant and anionic natural material surfactant on the low density foamed concrete. From the experiment, the vegetable soap of anionic natural material surfactants showed a higher foaming rate, more open pores, slightly lower compressive strength, and a higher permeability coefficient compared to the vegetable soap of anionic synthetic surfactants. It is believed that the natural material surfactants make not only the surface tension of the solution low but also the viscosity of slurry high.