• 공업화학
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• 제35권3호
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• pp.230-238
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• 2024

본 연구에서는 인지질계 양쪽성 계면활성제 CDP-W 첨가가 지질 소포체 막과의 상호 작용에 미치는 영향에 관하여 살펴보았다. 이를 위하여 CDP-W 양쪽성 계면활성제와 레시틴 S100-3의 임계 마이셀 농도 및 표면장력 등의 계면 물성을 측정하였다. 또한 pH 변화에 따른 1 wt% 계면활성제 수용액의 제타 전위 측정을 통하여 양쪽성 계면활성제 CDP-W가 양이온 계면활성제에서 음이온 계면활성제로 작용이 전환되는 등전점을 결정하였으며, 이 결과를 바탕으로 pH 변화 및 CDP-W 첨가가 리포좀의 평균 입자 크기, 다분산 지수 및 제타 전위 등과 같은 안정성에 미치는 영향에 살펴보았다. 또한 가장 안정한 상태의 리포좀이 형성되는 pH 6의 조건에서 CDP-W 첨가에 따른 리포좀 막의 형광 이방성, 변형성, 녹는 점 측정 등을 통하여 리포좀 막의 유동성 특성을 측정하고 리포좀 막의 유동성이 포집효율 및 안정성에 미치는 영향에 관하여 살펴보았다.

• 공업화학
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• 제10권7호
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• pp.1096-1098
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• 1999

MCM-41형의 메조포러스 구형 실리카 재료를 염기성 조건에서 양이온 계면활성제를 templating species로 사용하여 합성하였다. 본 실험에서 사용한 계면활성제로는 octyltrimetylammonium bromide, dodecyltrimetylammonium bromide, cetyltrimethylammonium bromide, octadecyltrimethyammonium bromide 및 cetylpyridium bromide이었다. 구형 MCM-41의 비표면적은 $1500m^2/g$나 되었으며 계면활성제의 알킬 사슬의 길이가 길어질수록 기공 크기는 증가하였다.

• 한국분말재료학회지
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• 제24권2호
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• pp.141-146
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• 2017

$Bi_2Te_3$ powders are recovered by wet chemical reduction for waste n-type thermoelectric chips, and the recovered particles with different morphologies are prepared using various surfactants such as cetyltrimethylammonium bromide (CTAB), sodium dodecylbenzenesulfonate (SDBS), and ethylenediaminetetraacetic acid (EDTA). When citric acid is added as the surfactant, the shape of the aggregated particles shows no distinctive features. On the other hand, rod-shaped particles are formed in the sample with CTAB, and sheet-like particles are synthesized with the addition of SDBS. Further, particles with a tripod shape are observed when EDTA is added as the surfactant. The growth mechanism of the particle shapes depending on the surfactant is investigated, with a focus on the nucleation and growth phenomena. These results help to elucidate the intrinsic formation mechanism of the rod, plate, and tripod structures of the $Bi_2Te_3$ recovered by the wet reduction process.

• 펄프종이기술
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• 제41권5호
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• pp.44-49
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• 2009

Old newspaper was deinked using commercial cellulolytic enzymes and a surfactant complex at low alkalinity. The properties of the deinked pulp(DIP) were evaluated and the suspended solids content, cationic demand, turbidity, and chemical oxygen demand(COD) of the process water were measured. The results can summarized as follows, 1. The brightness and yield of the DIP were improved using enzymatic surfactant complex deinking. 2. The amount of foaming during deinking with the enzyme surfactant complex was higher than that with synthetic surfactant deinking. However, it was not sufficient to cause process problem. 3. The pH and turbidity of the white water from deinking with the enzyme surfactant complex were similar to those of the white water from surfactant deinking. 4. The suspended solids content, cationic demand, and COD of the white water from deinking with the enzyme surfactant complex were improved compared to those of the white water from surfactant deinking.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 총회 및 춘계학술발표회
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• pp.418-421
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• 2003

Surfactant enhanced in-situ soil flushing was peformed to remediate the soil and groundwater at an oil contaminated site, and the effluent solution was treated by the chemical treatment process including DAF(Dissolved Air Flotation). A section from the contaminated site(4.5m$\times$4.5m$\times$6.0m) was selected for the research, which was composed of heterogeneous sandy and silt-sandy soils with average Hydraulic conductivity of 2.0$\times$10$^{-4}$ cm/sec. Two percent of sorbitan monooleate(POE 20) and 0.07% of iso-prophyl alcohol were mixed for the surfactant solution and 3 pore volumes of surfactant solution were injected to remove oil from the contaminant section. Four injection wells and two extraction wells were built in the section to flush surfactant solution. Water samples taken from extraction wells and the storage tank were analyzed by GC(gas-chromatography) for TPH concentration with different time. Five pore volumes of solution were extracted while TPH concentration in soil and groundwater at the section were below the Waste Water Discharge Limit(WWDL). Total 18.5kg of oil (TPH) was removed from the section. The concentration of heavy metals in the effluent solution also increased with the increase of TPH concentration, suggesting that the surfactant enhanced in-situ flushing be available to remove not only oil but heavy metals from contaminated sites. Results suggest that in-situ soil flushing and chemical treatment process including DAF could be a successful process to remediate contaminated sites distributed in Korea.

• Bulletin of the Korean Chemical Society
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• 제10권4호
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• pp.339-343
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• 1989

The interaction of cationic surfactants, n-alkyltrimethylammonium bromide ($C_nTAB$; n = 12, 14, 16) with anionic polyelectrolyte, poly(styrenesulfonate) (PSS) has been studied by surface tension measurement. In the absence of added salt, the cationic surfactants bind to PSS quantitatively up to ca. 60% coverage of anionic sites of the polyanion and the complexes were surface inactive. Further binding of the surfactant cations on PSS caused a sharp conformational transition of the surfactant/ PSS complexes to surface active complexes and accompanied precipitation. The binding showed a biphasic behavior in the presence of NaCl and cooperativity of the binding became less as the concentration of NaCl increased. Binding of the cationic surfactants on poly(vinylsulfonate) also showed the biphasic behavior and the cooperativity of the binding was much less even in the absence of NaCl. The binding of surfactant to PSS provided hydrophobic environment to solubilized pyrene and reduced the viscosity of the solution greatly even at surfactant concentrations well below cmc. This study indicated that the surfactant bound to PSS up to $60{\%}$ coverage of PSS sites are present as surfactant aggregates which are wrapped up with PSS chains, and hydrophobic interaction is an important factor in the binding of the surfactants to PSS.

• Journal of Industrial and Engineering Chemistry
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• 제67권
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• pp.72-79
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• 2018

Hybrid F2HX surfactants bearing a sulfate moiety and both hydrocarbon and fluorocarbon chains were prepared by the reaction of alkyl glycidyl ethers with fluoro-alcohol, and subsequent sulfation. The fluorocarbon number in F2HX was fixed at the shortest number possible (i.e., 2), while the hydrocarbon number (X) in the second chain was varied between 2, 4, 6, and 8. Their surface-active properties and emulsion stabilities were systematically estimated as a function of the X. Among them, F2H8 exhibited the optimal surfactant performance, which was comparable to previously reported surfactants and it was successfully applied in the emulsion polymerization of vinylidene fluoride.

• 한국재료학회지
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• 제15권5호
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• pp.340-347
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• 2005

Silver nanoparticles were synthesized by chemical reduction method from aqueous silver nitrate solution ana hydrazine as a reduction agent. The morphology, particle size and shape were dependent on the mixing method, reaction temperature and time, molar ratio of hydrazine and silver nitrate, the kind of surfactant, and the addition of surfactant. The stability of the colloidal silver was achieved by the adsorption of surfactant molecules onto the particle. Silver nanoparticles have a characteristic absorption maximum at 430 nm under UV irradiation. It was found that the colloid was nanometer m size and formed very stable dispersion of silver. The Ag nanoparticles obtained showed the spherical shape with the size range of 10-30 nm.

• Bulletin of the Korean Chemical Society
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• 제35권7호
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• pp.2009-2012
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• 2014

An anionic surfactant, sodium dodecylbenzene sulfonate (SDBS), was introduced during the ultrasonication process for exfoliation of graphene. The surfactant plays the roles of exfoliator and stabilizer by binding to the graphene surface. The obtained modified graphene was characterized by Fourier-transform infrared spectroscopy (FT-IR) and solid state $^{13}C$ CP/MAS NMR to analyze the binding between molecules, and by X-ray diffraction (XRD) to characterize the bulk structure. The resulting graphene exhibited good dispersion stability in both water and organic solvents.

• Korean Membrane Journal
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• 제1권1호
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• pp.43-49
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• 1999

Separation of soluble oil was investigated during filtration of cutting oil emulsion using various commercial ultrafiltration membranes. The surface properties of membranes used were hydrophilic hydrophobic and modified surfaces by various surfactant pretreatments. Conditions varied include stirring speed transmeembrane pressure membrane type and surfactant type for pretreatment. The results give some indication of mechanisms occurring at the membrane surface. Surfactant pretreatments significantly improved water flux and UF flux of hydrophilic regenerated cellulose(up to 2.4x for YM100) and hydrophobic polysulfone (up to 2.2x for PTHK) membranes depending on surfactant type and operating conditions. The UF flux enhancement was attributed to membrane swelling and reduction of interfacial surface tension between oil droplets and membrane surface. unexpectedly the hydrophilic membranes revealed greater flux enhancement than the hydrophobic membranes. The results also showed a greater improvement in UF flux at lower operating pressure.