• Proceedings of the Membrane Society of Korea Conference
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• 2008.05a
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• pp.61-61
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• 2008

• Clean Technology
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• v.9 no.4
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• pp.169-177
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• 2003

In order to develope a clean technology by liquid-supported membrane of ionic liquid/PVDF, the solubility of R22 and HFP gases using BMIBF4 as ionic liquid were measured at temperatures from 0 to $30^{\circ}C$, at total pressures up to 4 bars. The solubility of R22 in this ionic liquid was shown a rapid increasing tendency with increases of pressure and decreases of temperature, respectively, whereas the solubility of HFP was showed only a little in the same conditions. Based on these results, liquid-supported membranes of ionic liquid/PVDF were prepared by variables of the deposition amount of ionic liquid in polymer matrix, PVDF and were applied to the separation of fluoro-gases(R22, HFP) including $N_2$ gas. The permeability of R22 was rapidly increased by depending on the deposition amounts of ionic liquid, whereas both of HFP and $N_2$ were just showed so little. Especially, the diffusivity coefficient and solubility parameter of R22 were increased by lower operating temperatures and increased deposition amount of ionic liquid in 1iquid membrane. In conclusion, the selectivity of R22 against HFP was changed to 10-45 times depending on both of operating temperatures and the deposition amount of ionic liquid in BMIBF4/PVDF liquid membrane.

• Applied Chemistry for Engineering
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• v.8 no.4
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• pp.551-559
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• 1997

The stability of liquid membrane in the extraction process was investigated through the extraction of the Zn component by using W/O/W emulsion type liquid surfactant membrane which was $D_2EHPA-Kerosene-Span$ $80-H_2SO_4$ system. The highest stability for liquid membrane through the Zn extraction process was obtained under the following conditions. That conditions were that span 80 concentration, as surfactant, of 2~3 vol.%;$D_2EHPA$ concentration, as extractant, of 5~7 vol.%;paraffin oil concentration, as membrane strengthening agent, of 10 vol.%;emulsion volume ratio to the external aqueous phase volume of 0.1, and internal aqueous phase volume ratio to the organic phase volume of 1.0.

• Membrane Journal
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• v.15 no.3
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• pp.187-197
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• 2005

A membrane contactor is a device that achieves liquid/liquid or gas/liquid mass transfer without dispersion of one phase within another. This is accomplished by passing the fluids on opposite sides of a microporous membrane. This approach offers a number of important advantages over conventional dispersed phase contactors, including absence of emulsions, no flooding at high flow rates, no unloading at low flow rates, and high interfacial area. This article provides a general review of membrane contactors, including operating principles and applications.

• Proceedings of the Membrane Society of Korea Conference
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• 1994.10a
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• pp.36-37
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• 1994

Sirkar등[1]이 많이 연구한 hollow-fiber contained liquid membrane방식보다 막내부에서의 물질전달 저항을 크게 낮출 수 있는 이른바 flowing liquid membrane방법을 Teramoto등[2]은 제안하였다. 좀더 발전된 membrane absorber방식으로서 평판형(flat-sheet type)막으로 흡수(absorption) 및 탈착(desorption)모듈을 구성하고, monoethanolamine 흡수제(absorbent)로 $Co_2/CH_4$ 분리에 적용하여 선택도를 크게 향상시킨 기존의 실험결과도 볼 수 있다. 막에서의 기-후 접촉과 반응이 수반된 물질전달에 의한 기체흡수 현상에 관해 많은 이론해석과 실험결과가 연구된 바 있다. 본 연구에서는 이산화탄소와 같은 산성기체(acid gas)의 분리에 주로 적용될 새로운 방식의 순환식 중공사막 흡수기 (circulatory hollow-fiber membrane absorber: HFMA)를 제안하고 이의 실제적용에 대한 기초로서 모델해석에 의한 분리성능을 예측하였다.

• Proceedings of the Membrane Society of Korea Conference
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• 1999.07a
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• pp.3-7
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• 1999

Government efforts on membrane technology started in early 1980 with Membrane Development Program supported by the Ministry of Science and Technology. Several independent research projects on liquid separation, gas separation, hollow fiber producing program etc. were carried out during the 1980s. The RaCER was commissioned by MOCI for the general management of the project which had its aims in establishing the base for developing membranes, modules and systems for liquid separation in August 1993. More recently, in June 1995, a program for developing membranes for oxygen separation, nitrogen separation and hydrogen separation was initiated. This paper outlines the brief history of membrane technology development in Korea from the introduction of membrane filtration technology during the late 1960s to present.

• Proceedings of the Membrane Society of Korea Conference
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• 1993.04a
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• pp.25-27
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• 1993

Multiphase equilibrium-based processes for separation and purification generally utilize dispersed systems in which one phase is dispersed in the other as bubbles or drops or thin films. Using microporous membranes, novel techniques have been developed such that multiphase processes can now be carried out in a nondispersive fashion for gas-liquid (Sirkar, 1992) and liquid-liquid (Prasad and Sirkar, 1992) contacting processes. Among such processes, only nondispersive solvent extraction of pollutants using microporous membranes will be of concern here. These processes employ immobilized immiscible phase interfaces at the pore mouths in a microporous membrane. Through such interfaces, solutes are extracted into the solvent as two immiscible phases flow on two sides of a microporous membrane. Many advantages of such a technique over conventional dispersion-based extractors have been summarized (Prasad and Sirkar, 1992).

• Bulletin of the Korean Chemical Society
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• v.26 no.6
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• pp.930-934
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• 2005

A chloroform membrane system containing a given mixture of benzylaza-12-crown-4 and oleic acid is introduced for the selective and efficient transport of $Pb^{2+}$ ion. The transport was capable of moving metal ions ‘up-hill’. In the presence of ${S_2O_3}^{2-}$ion as a suitable metal ion acceptor in the receiving phase, the amount of lead ion transport across the liquid membrane after 150 minutes is (95.0 ${\pm}$ 1.7)%. The selectivity and efficiency of lead transport from aqueous solution containing $Tl^+,\;Ag^+,\;Mg^{2+},\;Ca^{2+},\;Co^{2+},$ $Ni^{2+},\;Cu^{2+},\;Zn^{2+},\;Hg^{2+}$ and $Cd^{2+}$were investigated. In the presence of thiosulfate as a suitable masking agent in the source phase, the interfering effects of $Ag^+\;and\;Cu^{2+}$ were diminished drastically.

• Korean Membrane Journal
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• v.4 no.1
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• pp.36-40
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• 2002

The diffusion coefficients of ions in the reverse transport system using the carrier mediated membrane were estimated from the diffusional membrane permeabilities and the ion activity in membrane system. In the aqueous alkali metal ions-membrane system diffusional flux of alkali metal ions driven by coupled proton was analyzed. The aqueous phase I contained NaOH solution and the aqueous phase II also contained NaCl and HCl mixed solution. The concentration of Na ions of both phases were $10^{0},\;10^{-1},\;10^{-2},\;5{\times}10^{-1}\;and\;5{\times}10^{-2}\;mol{\cdot}dm^{-3}$ and the concentration of HCI in aqueous phase II was always kept at $1{\times}10^{-1}\;mol{\cdot}dm^{-3}$. Moreover, the carrier concentration in liquid membrane was $10^{-2}\;mol{\cdot}dm^{-3}$. The results indicated that the diffusion coefficients depend strongly on the concentration of both phases electrolyte solution equilibriated with the membrane. The points were interpreted in terms of the energy barrier theory. Furthermore, eliminating the potential terms from the membrane equation was derived.

• Membrane and Water Treatment
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• v.4 no.2
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• pp.95-108
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• 2013

Metal ions exist in seawater, groundwater and industrial wastewaters. These source waters can be recycled if their concentrations are reduced. A number of processes can be applied for this purpose. Liquid-liquid extraction is one of the promising methods. In this paper, experimental results are presented on the removal of Cr(VI) using Aliquat-336, a reactive carrier, in sunflower oil (a non-toxic solvent). The performance of this new system is compared with those of kerosene (a toxic solvent). The extent of removal of Cr(VI) from samples with high and low concentrations are presented. The process was upgraded to a bench-scale module that can selectively remove about 50-90% Cr(VI) from samples of groundwater. Thus this process can produce water within the acceptable range for recycling and for use in secondary purposes such as irrigation.