• 한국막학회:학술대회논문집
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• 한국막학회 1999년도 추계 총회 및 학술발표회
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• pp.114-116
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• 1999

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1998년도 가을 학술발표회 논문집
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• pp.325-332
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• 1998

The use of air-supported membrane has considerable attention in recent years. There are, however, a number of problems in the behavior of these structures that have not been fully investigated. For example, the problem of local loafing on such membranes has not been analyzed yet. The paper presents an analysis of internal and external potential energy of a spherical air-supported membrane with vertical longitudinal axis, subjected to local loadings. An internal pressure value of the applied load is established at which tile potential of these structures change positive. During such change the loading portion of the membrane comes into work beyond stable state. The mathematical method is used throughout the paper in obtaining solution. For the mathematical modeling, two assumption are used. One is the theta's elimination and the other is the infinite condition. The paper is illustrating the examples of spherical air membrane dome subjected to local load.

• 멤브레인
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• 제2권1호
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• pp.49-58
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• 1992

Functionalized organic polymers have been used as supports for heterogenized homogeneous catalytic process[1]. Sprcific advantages of using these resins as support reagents have been reviewed[2-4]. These include: -ease of by-product separation from the main reaction product usuallyby simple filtration. -prevention of intermolecular reaction of reactive species or functional groups by simulating high dilution conditions[5]. -utility of the "fish-hook" principle in which a minor component in fished out of a large excess substrate by the insoluble polymer[6]. -the possibility of reusing recovered reagents as well as eliminating the use of volatile or noxious substances[7]. Catalysis by ion-exchange membranes is perhaps one of the latest examples of the use of a polymer-supported species. Conceptually, catalysts on membrane supports offer several possible advantages over traditional powder type systems. They are: (1) Membranes immobilize the catalyst, preventing agglomeration. (2) Filtration is unnecessary for the catalyst separation and so complete catalyst recovery is facilitated. (3) Catalytyic and separation processes can be combined, allowing membrane supported catalysts for the continous flow reactors. reactors.

• 분석과학
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• 제12권3호
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• pp.224-229
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• 1999

최근 캐리어를 이용한 액체막의 연구가 대단히 활발하다. 항생물질의 모넨신을 사용하여 옥타놀의 유기용매에 용해시켜 양이온교환막을 제조하였다. 이막의 평가를 Nernst-Planck식과 Fick식으로 막전위와 물질의 투과선택도를 분석하였다. 사용한 알카리이온의 농도에 대한 높은 투과선택성을 확인하였고, 시간에 따른 이온농도값은 선형관계를 알았다. 그러나 이온의 높은농도에서 변화량은 선형이 아니였다. 이를 위한 해석은 정지층(Stagnent Layer)을 하나 더 도입하여 업 - 힐 수송에서 직선관계를 얻었다.

• Bulletin of the Korean Chemical Society
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• 제22권10호
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• pp.1076-1080
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• 2001

• Membrane and Water Treatment
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• 제9권6호
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• pp.463-471
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• 2018

The present paper deals with the liquid-liquid extraction and flat sheet supported liquid membrane studies of Pd(II) separation from nitric acid medium using a novel synthesized ligand, namely, N,N,N',N'-tetraethyl-2,2-thiodiethanthiodiglycolamide (TETEDGA). The effect of various diluents and stripping reagents on the extraction of Pd(II) was studied. The liquid-liquid extraction studies showed complete extraction of Pd(II) in ~ 5 min. The influence of nitric acid and TETEDGA concentration on the distribution of Pd(II) has been investigated. The increase in nitric acid concentration resulted in increase in extraction of Pd(II). Stoichiometry of the extracted species was found to be $Pd(NO_3)_2{\cdot}TETEDGA$ by slope analysis method. Extraction studies with SSCD solution showed negligible uptake of Pt, Cr, Ni, and Fe, thus showing very high selectivity and extractability of TETEDGA for Pd(II). The flat sheet supported liquid membrane studies showed quantitative transport of Pd(II), ~99%, from the feed ($3M\;HNO_3$) to the strippant (0.02 M thiourea diluted in $0.4M\;HNO_3$) using 0.01 M TETEDGA as a carrier diluted in n-dodecane. Extraction time was ~160 min. Parameters such as feed acidity, TETEDGA concentration in membrane phase, membrane porosity etc. were optimized to achieve maximum transport rate. Permeability coefficient value of $2.66{\times}10^{-3}cm/s$ was observed using TETEDGA (0.01 M) as carrier, at 3 M, $HNO_3$ feed acidity across $0.2{\mu}m$ PTFE as membrane. The membrane was found to be stable over five runs of the operation.

• 한국재료학회지
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• 제10권9호
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• pp.619-623
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• 2000

알루미나 여과막은 boehmite 분말 (${\Upsilon}-AlOOH$)을 이용하여 졸-겔법으로 준비되어졌다. 제조된 여과막은 상전이 온도와 미세구조 변화를 관찰하기 위해 지지체 없이 형성된 여과막을 제조하였다. 여과 공정의 응용에서 균일한 기공크기와 분포를 제어하는 것이 중용하다. 다공성 담체 위에 형성된 여과막과 다공성 담체 없이 형성된 여과막의 ${\theta}-to\;{\alpha}-AL_2O_3$로의 상전이는 박막 XRD를 이용하여 분석하였고, 미세구조의 변화의 관찰은 주사전자현미경(SEM)을 사용하여 관찰하였다. XRD에서 분석된 결과는 다공성 담체 위에 형성된 여과막이 다공성 담체 없이 형성된 여과막과 비교하여 $100^{\circ}C$ 더 높은 상전이 온도를 가지는 것을 보여주었다. 이런 유사한 효과는 여과막의 미세구조 변화에서도 관찰되었다.

• Membrane and Water Treatment
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• 제6권3호
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• pp.251-262
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• 2015

In this work the preparation and characterization of a membrane containing a uniform mesoporous Titanium oxide top layer on a porous stainless steel substrate has been studied. The 316 L stainless steel substrate was prepared by powder metallurgy technique and modified by soaking-rolling and fast drying method. The mesoporous titania membrane was fabricated via the sol-gel method. Morphological studies were performed on both supported and unsupported membranes using scanning electron microscope (SEM) and field emission scanning microscope (FESEM). The membranes were also characterized using X-ray diffraction (XRD) and $N_2$-adsorption / desorption measurement (BET analyses). It was revealed that a defect-free anatase membrane with a thickness of $1.6{\mu}m$ and 4.3 nm average pore size can be produced. In order to evaluate the performance of the supported membrane, single-gas permeation experiments were carried out at room temperature with nitrogen gas. The permeability coefficient of the fabricated membrane was $4{\times}10^{-8}\;lit\;s^{-1}\;Pa^{-1}\;cm^{-1}$.

• Journal of Electrochemical Science and Technology
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• 제10권1호
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• pp.14-21
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• 2019

Supported liquid membrane process usually is used for recovering or enrichment of valuable metals in the industrial wastewater. But, even if the metals in the wastewater was separated with high chemical selectivity, it cannot be enough concentrated since separation performance of supported liquid membrane (SLM) process is limited by concentration gradient between feed solution and stripping solution. If metal concentration in the stripping solution to be enough low, transport of metal through membrane can be accomplishment constantly. Therefore, Electrodialysis (ED) has been placed after SLM process and the stripping solution of SLM was used as the feed solution for the ED process. Transport of ions in the solutions is successfully performed by ED process. Thus, the metal concentration in the stripping solution does not rise as to stop ion transport. Besides, valuable metals easily are concentrated by ED process for re-use. In this study, effects of operation parameters like initial Cd(II) concentration, HCl concentration in the feed solution of SLM and applied voltage are investigated on separation efficiency, flux and permeability of the both processes. As the feed solution concentration increased, all performance values has increased. When initial concentration of 100 mg/L is used, separation performances (SP) are 55% and 70%, for SLM and consecutive process, respectively. The best HCl concentration in the feed solution of SLM has determined as 2 M, in this conditions SP are 64% and 72%, for SLM and consecutive process, respectively. With increased of applied voltage on ED process, SP of the consecutive process has been raised from 72% to 83%. According to the obtained experimental data, consecutive process has better separation performance than SLM. When the separation performances of both processes were compared for the same operating conditions, it was determined higher the separation efficiency, permeability and flux values of the consecutive process, 8%, 9% and %10.6, respectively. Consequently, the use of the consecutive process increases the performance efficiency of both processes. The consecutive process studied has quite a good chemical separation efficiency, and enrichment capability. Moreover, this process requires few water and energy.

• Biotechnology and Bioprocess Engineering:BBE
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• 제3권1호
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• pp.24-31
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• 1998

The separation and concentration of L-phenylalanine (L-Phe) using a supported liquid membrane (SLM) is investigated. A cation complex agent, di-2-ethylhexyl phosphoric acid (D2EHPA), is used as a carrier in the SLM with n-Heptane as a solvent. The reaction order and equilibrium constant in the formation reaction of L-phe-carrier complex are obtained from the extraction experiment. A mathematical model for a carrier mediated counter transport process is proposed to estimate the diffusion coefficient of L-phe-carrier complexly in the liquid membrant. Permeation experiments of L-phe using a SLM are performed under various operating conditions and optimum conditions for the transport of L-phe are obtained. Concentration of L-phe in the strip phase against its concentration is observed. Transport rate of glucose through liquid membrane is less than that of L-phe in the competitive transport of L-phe and glucose. And the existence of glucose reduced the transport rate of L-phe. The performance of separation with continuous strip phase is increased due to the dilution effect in the strip phase.