• Title/Summary/Keyword: Ionic surfactant

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Surface Conductance Modulation of Single-Walled Carbon Nanotubes and Effects on Dielectrophoresis (단일벽 탄소나노튜브의 표면 전도도 조절 및 유전영동에 대한 영향)

  • Hong Seung-hyun;Jung Se-hun;Kim Young-jin;Choi Jae-bong;Baik Seunghyun
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.30 no.2 s.245
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    • pp.179-186
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    • 2006
  • Dielectrophoresis has received considerable attention for separating nanotubes according to electronic types. Here we examine the effects of surface conductivity of semiconducting single-walled carbon nanotubes (SWNT), induced by ionic surfactants, on the sign of dielectrophoretic force. The crossover frequency of semiconducting SWNT increases rapidly as the conductivity ratio between the particle and medium increases, leading to an incomplete separation of ionic surfactant suspended SWNT at an electric field frequency of 10 MHz. The surface charge of SWNT is neutralized by an equimolar mixture of anionic surfactant sodium dodecyl sulfate (SDS) and cationic surfactant cetyltrimenthylammonium bromide (CTAB), resulting in negative dielectrophoresis of semiconducting species at 10 MHz. A comparative Raman spectroscopy study shows a nearly complete separation of metallic SWNT.

A Comparison Study on Drag Reduction Characteristics of Polymer and Surfactant as Drag Reduction Additive (고분자불질 및 계면활성제의 유동마찰 저감 특성 비교 연구)

  • Cho, Sung-Hwan;Ryu, Jae-Sung;Kim, Seong-Su;Jung, Sang-Hoon;Yoon, Seok-Mann
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.22 no.6
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    • pp.398-403
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    • 2010
  • The drag reduction(DR) of non-ionic surfactant and polymer according to the variation of fluid velocity, temperature and surfactant concentration was investigated experimentally. For this experiment, the kind of surfactant was non ionic amine-oxide and the kinds of polymer were polyacrylamide and xantan gum. An experimental apparatus equipped with one water storage tanks was built and two flow meters, two pressure gauges for data logging system was installed. Results showed that the kinds of polymer, polyacrylamide and xantan gum, had DR of below 20% for below 500 ppm in fluid temperature of $50{\sim}80^{\circ}C$. But the kind of surfactant, amine oxide, had DR of above 40% for 500~1000 ppm in fluid temperature of $50{\sim}80^{\circ}C$. As a result, amin oxide showed better materials to use to the district heating system.

Effect of Electrolyte on the Adhesion of Particulate Soil to Fabric in the Surfactant Solution-Adhesion of -$\alpha$-$Fe_2O_3$Particles to PET Fabric- (계면활성제 용액네에서 고형오구의 직물에서의 부착에 영향을 주는 전해질 효과-$\alpha$-$Fe_2O_3$입자의 PET 섬유직물에의 부착-)

  • 강인숙;김병주
    • Journal of the Korean Society of Clothing and Textiles
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    • v.25 no.8
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    • pp.1465-1474
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    • 2001
  • The dispersion stability of particles and the adsorption of surfactant were examined as a fundamental environment to adhesion of particulate soil to fabric. The adsorption of surfactant on the PEF fabrics decreased with the addition of electrolytes and decreased with increasing the ionic strengths showed similar tendency to PET fabric. And the dispersion force of $\alpha$-Fe$_2$O$_3$particles decreased with the addition of electrolyte. The adhesion of particulate soil to fabric, increased with decreasing the adsorption of surfactant the correlation between the two was high at low ionic strength. The correlation between the adsorption of surfactants on $\alpha$-Fe$_2$O$_3$ particles and the adhesion of particles to fabric was smaller as shown in the correlation between the adsorption of surfactants on fiber substrate and the adhesion of particles on fabric. However, the correlation between the adhesion of particles to fabric and the stability of particle dispersion was relatively more significant.

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Rheology of hydrophobic-alkali-soluble-emulsions (HASE) and the effects of surfactants

  • Lau, A.K.M.;Tiu, C.;Kealy, T.;Tam, K.C.
    • Korea-Australia Rheology Journal
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    • v.14 no.1
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    • pp.1-9
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    • 2002
  • Steady and dynamic shear properties of two hydrophobically modified alkali soluble emulsions (HASE), NPJI and NPJ2, were experimentally investigated. At the same polymer concentration, NPJ1 is appreciably more viscous and elastic than NPJ2. The high hydrophobicity of NPJ1 allows hydrophobic associations and more junction sites to be created, leading to the formation of a network structure. Under shear deformation, NPJ1 exhibits shear-thinning behaviour as compared with Newtonian characteristics of NPJ2. NPJ1 and NPJ2 exhibit a very high and a low level of elasticity respectively over the frequency range tested. For NPJ1, a crossover frequency appears, which is shifted to lower frequencies and hence, longer relaxation times, as concentration increases. Three different surfactants anionic SDS, cationic CTAB, and non-ionic TX-100 were employed to examine the effects of surfactants on the rheology of HASE. Due to the different ionic behaviour of the surfactant, each type of surfactant imposed different electrostatic interactions on the two HASE polymers. In general, at low surfactant concentration, a gradual increase in viscosity is observed until a maximum is reached, beyond which a continuous reduction of viscosity ensues. Viscosity development is a combined result of HASE-surfactant interactions, accompanied by constant rearrangement of the hydrophobic associative junctions, and electrostatic interactions.

AEROBIC DEGRADATION OF A NON-IONIC SURFACTANT IN A MEMBRANE BIOREACTOR(MBR)

  • Choi, In-Su;Wiesmann, Udo
    • Environmental Engineering Research
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    • v.12 no.2
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    • pp.81-91
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    • 2007
  • A membrane bioreactor (MBR) was used to investigate the aerobic degradation of foam active substance - non-ionic surfactant, APG 2000 UP. The surface aeration using the propeller loop reactor (PLR) guaranteed sufficient $O_2$ for substrate removal and bacteria growth and avoided foam development. Moreover, the cross-flow membrane filtration enabled the separation of the bacteria still loaded with surfactant in the collecting container. The biological degradation of the surfactant with varying hydraulic retention time (HRT) and influent concentration $c_{S0}$ showed high substrate removal of nearly 95% at high volumetric loading rates up to $7.4\;kgCOD\;m^{-3}d^{-1}$ and at sludge loading rates up to 1.8 kgCOD $(kgVSS\;d)^{-1}$ for biomass concentration $c_B\;{\approx}\;constant $. The increasing $c_B$ from 3.4 to $14.5\;gL^{-1}$ TSS respectively sludge retention time (SRT) from 5.1 to 442 d under complete biomass retention by the membrane filtration resulted in high removal of substrate ${\alpha}\;>\;90%$ with reducing excess sludge production.

Experimental Study on Drag Reduction Effects of New Non-Ionic Surfactants

  • Tae, Choon-Sub;Cho, Sung-Hwan
    • International Journal of Air-Conditioning and Refrigeration
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    • v.14 no.4
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    • pp.147-155
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    • 2006
  • The drag reduction (DR) and heat transfer efficiency reduction (ER) of non-ionic surfactant were investigated as a function of fluid velocity, temperature, and surfactant concentration. An experimental apparatus consisting of two temperature controlled water storage tanks, pumps, test specimen pipe and the piping network, two flow meters, two pressure gauges, a heat exchanger, and data logging system was built. From the experimental results, it was concluded that existing alkyl ammonium surfactant (CTAC Cethyl Trimethyl Ammonium Chloride) had DR of $0.6{\sim}0.8$ at $1,000{\sim}2,000ppm$ concentration with fluid temperature ranging between $50{\sim}60^{\circ}C$. However, the DR was very low when the fluid temperature was $70{\sim}80^{\circ}C$. The new amine oxide and betaine surfactant(SAOB Stearyl Amine Oxide + Betaine) had lower DR at fluid temperatures ranging between $50{\sim}60^{\circ}C$ compared with CTAC. However, with fluid temperature ranging between $70{\sim}80^{\circ}C$ the DR was $0.6{\sim}0.8$ when the concentration level was $1,000{\sim}2,000ppm$.

Solubilization Isotherms of Chlorobenzene in ionic Surfactant Solutions

  • Baek, Ki-Tae;Yang, Ji-Won
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2003.04a
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    • pp.201-204
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    • 2003
  • Solubilization isotherms of 1-chlorobenzene (MCB) and 1, 2-dichlorobenzene (DCB) were investigated in ionic surfactant solutions such as sodium dodecyl sulfate (SDS), cetylpyridinium chloride (CPC), and dedecyltrimethylammonium chloride (DMAC). The solubilization extent of DCB was much higher than that of MCB because of the main driving force of solubilization Is hydrophobic interactions between chlorobenzenes and hydrophobic interior of ionic micelles and DCB is more hydrophobic than MCB. CPC showed highest solubilization capacity because of longest hydrophobic tails. Simultaneous solubilization of MCB and DCB decreased slightly the extent solubilization of both MCB and DCB because the solubilization locus in the micelles is same.

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Effect of Fatty Acid and Non-ionic Surfactant on the Deinkability of Mixed Recovered Paper (혼합폐지의 탈묵효율에 미치는 지방산과 비이온성 계면활성제의 영향)

  • Seo, Jin Ho;Choi, Do Chim;Ryu, Jeong Yong;Chung, Sung Hyun
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.47 no.2
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    • pp.34-41
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    • 2015
  • Recovered paper has been widely used as a main raw material of papermaking in Korea. Recycling of recovered paper helps to reduce production cost and preserve an environment. To recycle recovered paper efficiently, de-inking is a key process in recycling mills. De-inking process would be affected by various influencing factors such as the type of de-inking agent, mixed ratio of recovered paper, season, and process conditions. In this study, fatty acid and nonionic surfactant were used as the de-inking agent in froth-flotation process of mixed recovered paper. De-inking properties of mixed recovered paper were investigated according to the addition level of each chemical. Nonionic surfactant had a small effect on de-inking efficiency of mixed recovered paper due to decreased reject. As the additional level of fatty acid increases, fragmented ink particles increased and then optical properties of recycled paper decreased because fragmented ink particles adsorbed onto the fiber surface.

A Study on the Adsorption of Anionic Surfactant by Various Textile Fibers and Rinsing Efficiency in Washing Process (세척시 섬유의 음이온계 계면활성제 흡착과 헹구기 효과에 관한 연구)

  • Park, Son Kyeong;Kim, Sung Reon
    • Journal of the Korean Society of Clothing and Textiles
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    • v.17 no.1
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    • pp.129-136
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    • 1993
  • Authors have studied the adsorption of anionic surfactant from detergent solutions on cotton fabric during washing process and have measured the concentration of the residual surfactant in rinsing solution. The relations with temperature and pre-soaking time to rinsing process have been studied. The adsorption of sodium dodecylbenzene sulfonate by various textile fibers has also been investigated. The results of this study are; 1. Three times rinsing is sufficient as, without pre-soaking, the concentration of the surfactant on fabric is stable from that time on. 2. The rinsing efficiency increases with temperature; at $25^{\circ}C$, $40^{\circ}C$, and $55^{\circ}C$, the concentrations of surfactant on the fabric after-rinsing are 68, 59, 51 mg/100 g of fiber respectively. 3. The longer the pre-soaking time, the lower the rinsing efficiency is; the 4hrs presoaked fabric shows increased surfactant concentration than the one without-soaking. And the increment is 35.8%. 4. The adsorption of sodium dodecylbenzene sulfonate on fabrics differs greatly with the chemical nature of the fiber; wool, silk and nylon which are thought to be ionic-adsorbants shows greater adsorption. 5. The adsorption of surfactant is more affected by the ionic character than the physical one, and the one with higher crystallinity such as cotton and polyester shows lower value than rayon or acetate.

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Synthesis of Magnesium Hydroxide and Surface Modification by Sorbitol Surfactants (수산화마그네슘의 합성과 솔비톨계 계면활성제를 이용한 표면개질)

  • Kang, Kuk-Hyoun;Hyun, Mi-Ho;Ryu, Kun-Sung;Lee, Dong-Kyu
    • Journal of the Korean Applied Science and Technology
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    • v.31 no.1
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    • pp.92-100
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    • 2014
  • Hydrophobic magnesium hydroxide [$Mg(OH)_2$] was modified by hydrothermal method using non-ionic sorbitol surfactant with Span series. Mganesium chloride [$MgCl_2$] and sodium hydroxide [NaOH] were used for synthesis of $Mg(OH)_2$. Also non-ionic surfactant were added as a stabilizer, dispersant and surface modifier. Addition of non-ionic surfactant was favourable to obtain small sized $Mg(OH)_2$ particles with better dispersibility and hydrophobic property of $Mg(OH)_2$ particles. The obtained product were characterized by particle size analysis(PSA), scanning electron microscope(SEM), energy dispersive spectroscopy(EDS), x-ray diffraction(XRD) and fourier transform infrared spectroscopy(FT-IR). The results show that the product are prepared with this method has a well hydrophobic properties and dispersity compared with unmodified $Mg(OH)_2$ particles. The improve properties of surface modified $Mg(OH)_2$ particles were also verified by similarity synthesizing under slightly different conditions.