• Prospectives of Industrial Chemistry
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• v.14 no.6
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• pp.21-28
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• 2011

이온교환막을 이용한 전기적 탈염기술은 막모듈 내에 양이온교환막과 음이온교환막을 교대로 장착시키고 모듈의 양단 전극에 전압을 적용함으로써 물속에 용존되어 있는 양이온과 음이온들을 전기의 힘을 이용하여 선택적으로 투과시키는 원리를 기반으로 하는 청정공정 기술이다. 이온교환막 공정은 전통적으로 산/알칼리의 생산, 산업폐수의 중금속의 제거, 해수의 담수화, 반도체 산업의 초순수의 제조, 해수에서 식염의 제조, 발효산업의 유기산 및 아미노산의 회수 등 다양한 산업분야에서 응용되어 왔다. 최근에는 이러한 기존의 응용분야에서 벗어나 새롭게 응용분야가 넓어지고 있다. 이온교환막과 다공성 탄소전극을 결합한 막축전식 해수담수화기술, 해수와 담수의 염도차를 이용한 역전기투석식 해수발전 등의 새로운 선택분리기능 및 응용분야를 가진 이온교환막의 개발 및 공정에 관한 연구가 활발히 이루어지고 있다. 그러나 국내에서는 이온교환막이 아직 상용화되지 않고 있어 이온교환막을 이용한 응용연구가 활발하게 진행되지 못하고 있어 그 개발이 시급하다. 본 논문에서는 먼저 이온교환막을 이용한 전기투석식 탈염기술, 물분해 전기투석, 전기탈이온 공정에 관한 동향을 조사하였다. 아울러 미래의 이온교환막의 응용기술인 해수담수화기술로서 역삼투법과 경쟁하여 에너지를 낮게 소모할 것으로 예상되는 분리막을 이용한 막축전식 탈염기술과 무한한 신재생에너지원인 해수와 담수를 이용한 역전기투석 해수발전기술에 대해 기술의 원리들과 최근의 연구동향 등을 정리하였다.

• Applied Chemistry for Engineering
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• v.7 no.6
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• pp.1132-1141
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• 1996

Heterogeneous cation exchange membrane(HCEM) was prepared with LLDPE(Linear Low Density Poly-ethylene) as binder, powdered cation exchange resins($diameter{\leq}149{\mu}m$) as ion-exchange material and glycerol as additive for electrodialysis and electrodeionization system. The weight ratio of (binder/ion exchange)/glycerol was (60%/40%)/5%, (55%/45%)/5%, (50%/50%)/5% and (40%/60%)/5%. The characterization of prepared HCEM was evaluated on mechanical, electrochemical, morphology and ion permeable properties. It was compared with commercial membrane. Electrochemical properties of HCEM of (50%/50% )/5% were very similar to value of IONPURE(commercial membrane), in which ion exchange capacity, ion transfer number and membrane resistance were to be 1.733meq/g, 0.96 and $16.08{\Omega}/cm^2$, respectively. Ion permeability of the membrane was better than that of IONPURE membrane. Compared with IONPURE membrane, the HCEM had a higher tensile strength and lower elongation and modulus, in which HCEM had tensile strength of $62.33kg/cm^2$, elongation of 87.42% and modulus of $658.53kg/cm^2$. The HCEM of (50%/50% )15% was optimum combination.

• Journal of Adhesion and Interface
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• v.15 no.1
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• pp.1-8
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• 2014

Ion exchange membrane is widely used in various fields such as electro dialysis, diffusion dialysis, redox flow battery, fuel cell. PVC cation exchange membrane using ultrasonic modification was prepared by sulfonation reaction in various sulfonation times. Sulfuric acid was used as a sulfonating agent with ultrasonic condition. We've characterized basic structure of sulfonated PVC cation exchange membrane by FT-IR, EDX, water uptake, ion exchange capacity (IEC), electrical resistance (ER), conductivity, ion transport number and surface morphology (SEM). The presence of sulfonic groups in the sulfonated PVC cation exchange membrane was confirmed by FT-IR. The maximum values of water uptake, IEC, electrical resistance and ion transport number were 40.2%, 0.87 meq/g, $35.2{\Omega}{\cdot}cm^2$ and 0.88, respectively.

• Applied Chemistry for Engineering
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• v.8 no.1
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• pp.67-75
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• 1997

Heterogeneous cation exchange membrane consisting of cation exchange resin particles (diameter of less than $149{\mu}$) which are finely dispersed in a polyethylene matrix, were produced as forms of sheet. The characteristics were measured after treating hot water or saturated sodium chloride. When membranes were treated with hot water or saturated sodium chloride, cation exchange resin particles swell and expand pushing away the polyethylene matrix of membranes. The above treatment results the formation of narrow cavities between a cation exchange resin particles and polyethylene matrix, and the formation of fine micro-cracks on the polyethylene matrix. Thus, we were obtained good physical and electrochemical properties. On the treatment with hot water or saturated sodium chloride, the optimum conditions for good heterogeneous cation exchange membrane were treatment time of 30min and treatment temperature of $90^{\circ}C$.

• Journal of the Korean Electrochemical Society
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• v.3 no.1
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• pp.57-62
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• 2000

Sulfonated Polysulfone (SPSF) cation-exchange membranes were synthesized by introducing various ratio of chlorosulfuric acid (CSA) onto the main chain of polysulfone (PSF). Properties such as ion exchange capacity, water content, liked ion concentration, and partition coefficient were measured, respectively. Through the analysis of DSC and TGA, it has been shown that glass transition temperature increased and weight loss decreased as sulfuric acid group concentration increased. Structure of membrane measured by AFM and SEM was seen to be asymmetric. Apparent diffusion coefficient of sodium ions through SPSF membrane by AC impedance was increased as sulfuric acid group concentration increased.

• Membrane Journal
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• v.15 no.2
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• pp.175-186
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• 2005

An electrodialysis process was operated for a long period to investigate the scale formation on the membrane surface. During the desalination process, concentration of $Ca^{2+}$ and $SO_4^{2-}$ ions increased continuously in the concentrate compartment and eventually caused precipitation on the cation exchange membrane (Neosepta CMX) surface. During the initial scale formation, the performance of the process and membrane characteristics did not show significant changes, except the decrease in limiting current density of the CMX membrane occurring due to increase in the salt concentration in the concentrate compartment. Eventually, the limiting current density of the fouled CMX membrane dropped significantly to $300\;A/m^2$ as water dissociation occurred in the CMX membrane. It was concluded that the fouling was caused mainly by the scale formation on the cation exchange membrane surface in the concentrate and consequent water dissociation. Also the scale formation was reasonably predicted by the solubility of $CaSO_4$.

• Membrane Journal
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• v.1 no.1
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• pp.44-54
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• 1991

Sulfonated polystyrene-divinylbenzene(PS-DVB) copolymer membranes were prepared using different diluents (toluene, cyclohexane, cyclohexanol), various diluent ratio and DVB contents. And initial fluxes of organic acids were investigated by varying pH and initial concentration. As a results, water content and ion-exchange capacity decreased with increasing DVB concetration. Among used diluents, cyclohexanol was the most efficient for building up the highest water content and ion-exchange capacity. In the experiment of permeation, carboxylic acid such as formic acid and acetic acid showed higher fluxes when pH was lower than pKa and amino add such as L-alanine showed minimum flux when pH was isoelectric value. The relationaship between initial fluxes and initial concentrations has been expressed by saturation kinetics.

• Membrane Journal
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• v.17 no.1
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• pp.37-43
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• 2007

The effect of anionic and cationic exchange polymer layer on the chronopotentiometry (CP) and current voltage curves (I-V) of charged composite membrane are investigated. Also, the ion transport near the interface between electrolyte and ionic exchange polymer membranes (anionic and cationic ones) and charged mosaic polymer composite membrane is studied. The results show that both anionic and cationic polymer exchange membranes exhibit lower voltage drop over range of applied current density and possess favorable industrial application potentials, especially at low KCl concentration. While the charged mosaic polymer composite membrane didn't show any current-voltage change, irrespective to the type and the concentration of used electrolyte. CP and I-V measurements are effectively used to give some fundamental understanding for ion transport behavior of ion exchange polymer membrane near the interlace.

• Membrane Journal
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• v.17 no.1
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• pp.54-60
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• 2007

In this research, the cation-exchange membrane (SS membrane) containing sulfonic acid group was prepared by radiation induced grafted polymerization onto a porous hollow fiber membrane to effectively remove ammonia which was produced by urea decomposition for peritoneum dialysis system. And the metal ionic cross-linking cation-exchange membrane (SS-M membrane) was prepared by the adsorption of metallic ions (Cu, Ni, Zn) to the SS membranes. The pure water flux and adsorption capacities of ammonia to SS and SS-M membranes were examined. The pure water flux of SS membrane decreased rapidly with the density of $SO_3H$ group increasing. As the metallic ions were adsorbed to the SS membrane, the pure water flux was increased. The adsorption capacities of ammonia at the SS membrane increased with increasing of density of $SO_3H$ group. The ion-exchange capacity of ammonia of the SS membrane was approximately proportional 1 : 1 to the density of $SO_3H$ group. The SS membrane had higher adsorption capacities than the SS-M membrane. The highest adsorption capacities of SS and SS-M membrane appeared the highest pH 9.

• Membrane Journal
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• v.32 no.2
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• pp.91-99
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• 2022

It is a global challenge to fulfill the demand for clean water at an affordable cost to all the strata of the population. Desalination of seawater as well as brackish water by the membrane separation process is a well-established and cost-efficient method. However, there is still inherent problem of membrane fouling, disposal of the reject as well as a capital-intensive process. While electrodialysis (ED) is a membrane-based separation process in which a driving force is the potential difference. The advantages of ED process are excellent efficiency and low operation cost. Ion exchange membrane (IEM) used in the ED process needs to have higher chemical and thermal stability along with excellent mechanical strength for long-term use without losing its efficiency. The ion exchange capacity of the ED membrane is largely dependent on the conductivity of IEMs. In this review, the modification strategy of the pristine membrane to enhance the stability and ion conductivity of cation exchange membrane (CEM) and anion exchange membrane (AEM) is discussed.