• Journal of the Korean Chemical Society
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• v.52 no.2
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• pp.111-117
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• 2008

critical micelle concentration (CMC) and the counter ion binding constant (B) in a mixed micellar state of the trimethyltetradecylammonium bromide (TTAB) with the polyoxyethylene (23) lauryl ether (Brij 35) at 25oC in water and in aqueous solutions of butanol isomers were determined as a function of 1 (the overall mole fraction of TTAB) 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 results say that the effects of butanol isomers on the micellization of TTAB/Brij 35 mixtures have been in the order of n-butanol>iso-butanol>t-butanol> water.

• Journal of Adhesion and Interface
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• v.9 no.2
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• pp.24-31
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• 2008

In this work, calcium hydroxide and magnesium carbonate as metal ionic crosslinking agents were used to introduce ionic crosslinking points to the ethylene vinylacetate (EVA) emulsions for the enhancement of water resistance and mechanical properties of emulsion films. The properties of EVA emulsion film were investigated in crosslinking density, thermal features, surface energy, and mechanical properties, such as tensile strength, elongation at break and tear strength. With the increasing content of metal ionic crosslinking agent, the crosslinking density of the EVA emulsion film increases, resulting into the improvement of water resistance. The surface energy and mechanical properties of the EVA emulsion film, however, showed somewhat different behaviors. The highest surface energy, tensile strength, and tear strength were observed when 0.4% for calcium hydroxide and 0.5% for magnesium carbonate was added respectively, because the EVA emulsion containing carboxylic acid forms strong carboxylate-metal bond of ionically-crosslinked system. Therefore, it can be concluded that metal ionic crosslinking agents, such as magnesium carbonate and calcium hydroxide are considered to improve water resistance and mechanical properties of the EVA emulsion.

• Polymer(Korea)
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• v.26 no.6
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• pp.759-766
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• 2002

Regular, spherical and isotropic open-microcellular foams having low density were prepared by the high internal phase emulsion (HIPE) polymerization mainly composed of styrene monomer and water The effects of Polymerization conditions. such as the content of water, divinylbenzene as a crosslinking agent and dodecane as a chain transfer agent, were investigated based on the tell size and foam properties. The microstructural morphology was observed using scanning electron microscopy (SEM) and the compression modulus of the foam was evaluated using compression test. The dropwise feeding of the aqueous phase into the oil phase was more effective than the batch feeding in producing the uniform and stable foam. Agitation speed and surfactant strongly influenced on the cell size and the window size between water droplets. Introduction of chain transfer agent increased the cell size, whereas it decreased the window size. Compression modulus increased with the crosslinking agent, but decreased with the chain transfer agent.

• Journal of the Korean Society of Urban Environment
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• v.18 no.4
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• pp.429-437
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• 2018

In this study, the mixed toxicity of heavy metals (Cu, Pb, Hg) and surfactants (SLS, ALS) was evaluated by using Vibrio fischeri and Daphnia magna. The sensitivity of ecotoxicity to heavy metals was sensitive to daphnia but the case of surfactants were more sensitive to Vibrio fischeri. Experimental results of Vibrio fischeri show that the toxicity value P(O) was lower than the predicted value P(E), and the antagonistic effect was observed when the heavy metal and the surfactant were mixed. It seems that SLS and ALS, which are anionic surfactants, have anionic form on the hydrophilic head, so that they have an antagonistic effect that they are bonded with heavy metal ion which is a cation type and the actual toxicity is lowered. In Daphnia magna, the results showed that antagonistic, additive and synergistic effects were in order as concentrations increased. As the concentration increases, Daphnia magna, which is highly sensitive to heavy metals, seems to have a synergistic effect with a rapid increase in mortality.

• Journal of Adhesion and Interface
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• v.20 no.2
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• pp.71-75
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• 2019

Tannic acid is one of the most commonly found polyphenols in the vegetable field. Initially, research on tannins concentrated on physiological functions such as antioxidants. Recently, however, tannic acid has attracted much interest as a molecular glue as it has been found to interact virtually all bio-macromolecules such as proteins and DNA. The various properties of tannic acid are expected to control the wettability of the surface, contribute to energy storage and generation, and show potential as a medical agent. Here, tannic acid will be discussed about the interaction of with bio-macromolecules as a molecular glue, surface modification, and utilization of itself as biomaterials.

• Journal of the Korean Chemical Society
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• v.43 no.6
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• pp.614-620
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• 1999

The critical micelle concentration (CMC) and the counterion binding constant (${\beta}$) at the CMC of the mixtures of Dodecylpyridinium chloride (DPC) and Tetradecyltrimethylammonium bromide (TTAB) have been determined from the concentration dependence of electrical conductance at various temperatures from $4^{\circ}C$ to $36^{\circ}C$. Thermodynamic parameters (${\Delta}C_p$, ${\Delta}G^o_m$, ${\Delta}H^o_m$ and ${\Delta}S^o_m$), associated with the micelle formation of DPC/TTAB mixtures, have been estimated from the temperature dependence of CMC and ${\beta}$values. The measured values of ${\Delta}C_p$ and ${\Delta}G^o_m$ are negative but the values of ${\Delta}S^o_m$ are positive in the whole measured temperature region. The values of ${\Delta}H^o_m$ are positive at low temperature region and negative at high temperature region. The results show that all of the thermodynamic parameters are dependent on temperature and mole fraction of DPC(${\alpha}_DPC$).

• Journal of the Korean GEO-environmental Society
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• v.13 no.6
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• pp.27-31
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• 2012

This study was designed to examine the feasibility of functionalized mesoporous silica as the adsorbent for benzene, toluene, ethylbenzene, and xylene isomers (BTEX) in groundwater. p-Xylene was used as the model compound of BTEX. A series of functionalized mesoporous silica with MCM-41 type of structure was synthesized using a co-condensation method. Monoamine, triamine, nitrile, phenyl, and octyl groups were functionalized to the mesoporous silica structure. Adsorption sites for p-Xylene in a functionalized mesoporous silica were Si-O-Si covalent bond, the surfactant, and the functional group. Octyl-functionalized mesoporous silica with stearyltrimethylammonium chloride as a surfactant showed the highest adsorption ability. The maximum xylene adsorption capacity of the octyl-functionalized mesoporous silica with stearyltrimethylammonium chloride based on Langmuir model was 4.17 mmol/g on $20^{\circ}C$, which was 2.9 times higher than that of MCM-41.

• Membrane Journal
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• v.19 no.2
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• pp.136-144
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• 2009

In this study, sodium dedocyl sulfate (SDS), which was anionic surfactant, was added for forming micelles to remove ferrous ions that could be contained with a small amount in industrial water. Then aggregates were formed by adsorption or binding of ferrous ions on the surface of micelles, and then rejected by ceramic membranes to remove ferrous ions. Ferrous concentration was fixed at 1mM and SDS was changed as $0{\sim}10mM$ to investigate the effect of the anionic surfactant. As a result, rejection rate of ferrous was the highest to 88.97% at 6mM. And we used ELS (Electrophoretic Light Scattering Spectrometer) to investigate particle size distribution of micellar aggregates depending on SDS concentration. Then distribution of large aggregates was the highest at 6mM. And we investigated effects of $N_2$-back-flushing time (BT) during periodic $N_2$-back-flushing on ceramic membranes. Finally optimal $N_2$-BT for NCMT-723l (pore size $0.10{\mu}m$) membrane was 20 sec.

• Polymer Science and Technology
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• v.15 no.3
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• pp.286-295
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• 2004

자기조립 단분자막 (self-assembled monolayers, SAMs)은 주어진 기질의 표면에 자발적으로 입혀진 규칙적으로 잘 정렬된 유기 분자막이다 (그림 1). SAMs의 제조에 이용되는 계면 활성제 분자는 그림 2에서 보여주듯이 세 개의 부분으로 이루어져 있다. 먼저 기질과 결합하는 머리 부분의 반응기, 규칙적인 분자 막 형성을 가능하게 하는 몸통 부분의 긴 알칸사슬, 그리고 분자 막의 기능을 좌우하는 꼬리 부분의 작용기로 나누어진다. 가장 간단한 작용기로는 알킬 그룹이 있으나 분자 막에 특수한 기능을 부여하기 위해서는 여러 가지 다른 그룹들 (예:NH$_2$, OH, COOH 등)이 이용되고 있다. (중략)

• Proceedings of the Korean Nuclear Society Conference
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• 1997.05b
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• pp.335-340
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• 1997

원전에서 발생하는 방사성 세탁폐액을 환경방사능 Zero Release 개념하에 완전히 처리하는 공정으로서 역삼투막을 이용한 방법이 연구되고 있는데 이에 앞서 역삼투막 공정의 주요 장애요소인 계면활성제 및 현탁물에 의한 탁도 제거를 위한 전처리 공정으로 활성탄과 한외여과막 결합장치를 제작하여 운전하였으며 실험 결과 90% 이상의 높은 세제 제거율과 60% 이상의 탁도 제거율을 얻을 수 있었다.