• KSBB Journal
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• v.7 no.1
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• pp.51-58
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• 1992

The use of watersoluble enzymes for chemical synthesis suffers from several limitations. The solubilization of biocatalyst (Enzymes and Cells) with reverse micelles or microemulsion could be a method for bioconveision of low water soluble substrates. In this review, We will discuss the properties and the potentials of reverse micelle for catalytic bioconversion and biotechnology.

• Journal of the Korean Society of Marine Environment & Safety
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• v.13 no.4
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• pp.51-54
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• 2007

Surfactants can be used as a cosmetics and chemical dispersants. The variation of critical micelle concentration(CMC) with temperature for hexadecyl pyridinium bromide over the range $40^{\circ}C$ to $60^{\circ}C$ has been measured by drop methods. Thermodynamic quantities for micellization of hexadecyl pyridinium bromide in water have been calculated by polynominal equation.

• Journal of the Korean Society of Marine Environment & Safety
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• v.14 no.2
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• pp.145-148
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• 2008

Cationic surfactant can be used as cosmetics and chemical dispersants. The variation of critical micelle concentration (CMC) with temperature over the range $40^{\circ}C$ to $60^{\circ}C$ for N-octadecyl pyridinium bromide was measured by drop methods. Thermodynamic quantities such as free energy, enthalpy, entropy and heat capacity for micellization of N-octadecyl pyridinium bromide in water were calculated by fourth-degree polynominal equation In the result, free energy change was decreased generally by the increment of temperature.

• Proceedings of the Membrane Society of Korea Conference
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• 1995.10a
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• pp.29-30
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• 1995

산업폐수는 종종 희석용액 내에 많은 유독성 물질을 함유하고 있다. 산업폐수를 처리하는 분리공정으로 역삼투막과 한외여과와 같은 막분리 기술은 분리 공정이 간단하고 상변화없이 폐수용량을 크게 감소시킬 수 있고 에너지 소모가 작은 장점을 가지고 있어 그 적용이 확산되고 있다. 계면활성제의 흡착성을 이용한 한외여과 막분리는 높은 막투과속도와 계면활성제의 높은 선택성이 결합된 것인데, Sodium Dodecyl Sulfate(SDS)와 같은 계면활성제를 이용하여 폐수로부터 불용성 중금속 이온과 독성의 유기물질을 분리하는 데에 적용할 수 있다. 임계미셀농도(CMC) 이상에서의 농도에서, 60~200 계면활성제 분자들이 거대분자나 미셀을 형성하면서 서로 응집된다. 그러므로 음으로 하전된 미셀과 결합된 금속 음이온은 2,000에서 10,000 범위의 분자량을 가지는데 역삼투막(RO)보다 작은 압력에서 상당히 큰 막투과속도를 가진 한외여과막에 의해 선택적으로 제거될 수 있다 본 연구의 목적은 중공사 한외여과막의 막투과속도에 미치는 인자들의 영향과, 계면활성제의 흡착성을 이용한 중공사 한외여과 막분리계 성능에 미치는 금속의 형태, S/M 몰비등의 효과를 결정하는데 있다.

• Journal of the Korean Chemical Society
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• v.50 no.5
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• pp.355-361
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• 2006

The critical micelle concentration (CMC) and the counterion binding constant (B) in a mixed micellar state of the sodium dodecylbenzenesulfonate (DBS) with the polyoxyethylene(23) lauryl ether (Brij 35) at 25oC in water and aqueous solutions of n-butanol (0.1M, 0.2M, and 0.3M) were determined as a function of a1 (the overall mole fraction of DBS) by the use of electric conductivity method and surface tensiometer method. Various thermodynamic parameters (Xi, i, Ci, aiM, , and Hmix) were calculated by means of the equations derived from the nonideal mixed micellar model. The effect of n-butanol on the micellization of the DBS/Brij 35 mixtures has been also studied by analyzing the measured and calculated thermodynamic parameters.

• Microbiology and Biotechnology Letters
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• v.7 no.1
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• pp.9-14
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• 1979

The hemicellulose fraction of ryegrass straw was extracted with NaOH and used for production of glucose isomerase by Streptomyces flavogriseus. Up to 25％ crude hemicellulose (20％ as pentosan) could he obtained by treating straw with 1 to 24％ NaOH. The yield of hemicellulose was increased proportionately with increasing NaOH concentration up to 4％, but the rate of increase was slowed thereafter. The optimum condition for hemicellulose extraction from ryegrass straw was to treat straw with 4％ NaOH for 3hrs at 9$0^{\circ}C$ or 24hrs at 3$0^{\circ}C$. Highest level of glucose isomerase activity (3.04 units/ml culture) was obtained when the organism was grown for 2 days at 3$0^{\circ}C$ on 2％ straw hemicellulose. The organism also produced a good quantity of glucose isomerase on xylan, xylose or H$_2$SO$_4$-hydrolysate of straw. The hemicellulose-extracted straw residue could be used as animal feed, because the residue had 75％ higher digestibility and 20％ better feed efficiency for weanling meadow voles than the untreated straw.

• Journal of the Korean Chemical Society
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• v.58 no.6
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• pp.517-523
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• 2014

The micellization of TTAB(tetradecyltrimethylammonium bromide) and the solubilization of 4-halogenated phenol isomers in aqueous solution of that surfactant in water have been studied by the UV-Vis spectrophotometric method. Those properties in aqueous solutions of NaCl and n-butanol have been also measured to determine the interactions between the micelle and 4-halogenated phenols and the solubilized sites of those molecules in the micelle. The results show that the values of ${\Delta}G^o_m$ and ${\Delta}G^o_s$ are all negative and the trends of those values depend on both the kinds and the concentrations of additives. Namely, by adding NaCl both ${\Delta}G^o_m$ and ${\Delta}G^o_s$ values are all decreasing, but by adding n-butanol the ${\Delta}G^o_m$ value decreases and the ${\Delta}G^o_s$ value increases.

• Journal of the Korean Chemical Society
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• v.55 no.2
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• pp.163-168
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• 2011

The variations of molar conductivity of various surfactants such as sodium caprylate, sodium laurate, sodium palmitate, sodium stearate, sodium oleate, sodium dodecyl sulphate, and lithium dodecyl sulphate with concentrations of the surfactants for each of the solutions consisting of mixtures of varying concentrations of N-methyl acetamide in water at constant temperature of $30{\pm}0.2^{\circ}C$ were studied. The critical micelle concentration (CMC) for each surfactant is measured. It is found that the CMC values in mixtures of N-methyl acetamide and water solutions of various surfactants are lower than the CMC values in water, and the driving force for micelle formation correlates with solvophobicity. The surfactant-solvent interactions that drive amphiphilic self-organization in N-methyl acetamide in water are discussed. Thermodynamic parameters were evaluated for micellar system to explain the results.

• Polymer(Korea)
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• v.30 no.6
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• pp.512-518
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• 2006

A biodegradable polymer poly((R) -3-hydroxybutyric acid) (PHB) was conjugated with a hydrophilic polymer poly(ethylene glycol) (PEG) by the ttansesterification reaction to form the amphiphilic block copolymer. PHB with low molecular weight ($3000{\sim}30000$) was appropriated for the drug delivery materials. High molecular weight PHB was hydrolyzed by an acid-catalyst to produce the low molecular weight one. Amphiphilic block copolymer was formed the self-assembled polymeric micelle system in the aqueous solution that the hydrophillic PEG was wraped the hydrophobic PHB. Generally, polymeric micelle forms the small particle between $10{\sim}200nm$. These polymeric micelle systems have been widely used for the drug delivery systems because they were biodegradable, biocompatible, non-toxic and patient compliant. The hydroxyl group of PEG was substituted with carboxyl group which has the reactivity to the ester group of PHB. Amphiphilic block copolymer was conjugated between PHB, and modified PEG at $176^{\circ}C$ which was higher than the melting point of PHB. Transesterification reaction was verified with DSC, FTIR, $^1H-NMR$. In the aqueous solution, critical micelle concentration (CMC) of the mPEG-co-PHB copolymer measured by the fluororescence scanning spectrometer was $5{\times}10^{-5}g/L$. The shape and size of the nanoparticle was taken by dynamic light scattering and atomic force microscopy. The size of the nanoparticle was about 130 nm and the shape was spherical. Our polymeric micelle system can be used as the passive targeting drug delivery system.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.39 no.4
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• pp.271-279
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• 2013

Water-soluble collagen (30 wt%) was entrapped within oil phase of lipstick using reversed micelle method to improve the moisture capacity of the lipstick. Reversed micelles containing collagen were prepared using caprylic/capric triglyceride as external phase and polyoxyethylene (10) octylphenyl ether (Triton X-100) and 1-dodecanol as surfactant and co-surfactant, respectively. The formation of reversed micelle encapsulating collagen was confirmed by measuring electric conductivity and UV-vis spectrum using methylene blue (MB). The stability and moisture capacity of the lipstick containing 20 wt% collagen encapsulated reversed micelles were observed by measuring rheology property, moisture content and amino acid content. The molecular ratio (W, water-pool) of water to surfactant (Triton X-100) in the most stable reversed micelle was ${\leq}$ 10. The hardness of the lipstick had no difference with that of the lipstick without reversed micelle, and the moisture content was increased to 59% and the amino acid content was 92.7%.