• 멤브레인
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• 제13권1호
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• pp.29-36
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• 2003

A characterization of the permeation and separation using single salt solution was carried out with charged composite membranes. Various charged composite membranes were fabricated by blending an ionic polymer with a nonionic polymer in different ratios. In this study, sodium alginate, chitosan and poly(vinyl alcohol) were employed as anionic, cationic and nonionic polymers, respectively. The permeation and separation behaviors of the aqueous salt solutions have been investigated through the charged composite membranes with various charge densities. As the content of the ionic polymer increased in the membrane, the hydrophilicity of the membrane increased, and pure water flux and the solution flux increased correspondingly, indicating that the permeation performance through the membrane is determined mainly by its hydrophilicity. Electrostatic interaction between the charged membrane and ionic solute molecules, that is, Donnan exclusion, was observed to be attributed to salt rejection to a greater extent, and molecular sieve mechanism was effective for the separation of salts under a similar electrostatic circumstance of solutes.

• 한국막학회:학술대회논문집
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• 한국막학회 2004년도 추계 총회 및 학술발표회
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• pp.9-11
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• 2004

• Bulletin of the Korean Chemical Society
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• 제25권5호
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• pp.665-667
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• 2004

In previous studies, charged mosaic membranes having two different fixed charges in the membrane matrix indicated unique transport behavior such as preferential material transport. In this study, the composite charged mosaic membrane endurable to mechanical pressure in practical application was investigated from the same aspect of solute and solvent transport as before. Lp and ${\omega}$ estimated by taking account of active layer thickness were satisfactorily consistent with those in mosaic membrane without reinforcement. On the other hand, the reflection coefficient s indicated the negative value that suggests preferential material transport.

• 멤브레인
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• 제17권1호
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• pp.37-43
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• 2007

크로노포텐시오미터(CP)와 전류-전압곡선(I-V)을 사용하여 음/양 이온 교환 층의 영향을 하전 모자이크 막에서 조사하였다. 역시 전해질과 음/양이온의 계면에서 이온수송을 실험하였다. 결과 음/양이온 교환 막은 전류범위에서 점점 전압강하가 나타났고, 특히 저 농도의 KCl 전위는 일정하였다. 한편 복합 하전 모자이크 막은 여러 전해질 수용액의 종류와 농도에 관계없이 전위의 변화는 없었다. CP와 I-V의 측정은 이온교환 막 계면에서 일어나는 이온수송에 대한 기초해석으로 대단히 유효하였다.

• 한국막학회:학술대회논문집
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• 한국막학회 2004년도 Proceedings of the second conference of aseanian membrane society
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• pp.109-112
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• 2004

The charged mosaic membranes having cation and anion exchange mixed groups within membrane were researched. The composite charged mosaic membrane was investigated from simultaneous transport such as solute and solvent flux. On the other hand, the reflection coefficient and salt flux coefficient were estimated by taking account of the cross constants of the phenomenological equation.(omitted)

• Membrane and Water Treatment
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• 제13권2호
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• pp.105-110
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• 2022

Al₂O₃ positively charged nanofiltration composite membrane was successfully prepared with aluminate coupling agent (ACA) as modifier, sodium bisulfite (NaHSO₃) and potassium persulfate (K₂S₂O₈) as initiator and methacryloyloxyethyl trimethylammonium chloride (DMC) as crosslinking monomer. The surface of the membrane before grafting and after polymerization were characterized by SEM and FT-IR. Three factor and three-level orthogonal experiments were designed to explore the optimal conditions for membrane preparation, and the optimal group was successfully prepared. The filtration experiments of different salt solutions were carried out, and the retention molecular weight was determined by polyethylene glycol (PEG). The results showed that the polymerization temperature had the greatest effect on the rejection rate, followed by the reaction time, and the concentration of DMC had the least effect on the rejection rate. The rejection rates of CaCl₂, MgSO₄, NaCl and Na₂SO₄ in the optimal group were 83.8%, 81.3%, 28.1% and 23.6% (average value), respectively. The molecule weight cut-off of 90% (MWCO) of the optimal group was about 460, which belongs to nanofiltration membrane.

• Membrane and Water Treatment
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• 제6권3호
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• pp.173-187
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• 2015

The goal of present work is the preparation of a novel positively charged nanofiltration (NF) membrane and its development for the cation removal of aqueous solutions. This NF membrane was fabricated by the surface modification of polysulfone (PSf) ultrafiltration support. The active top-layer was formed by interfacial cross-linking polymerization of poly(ethyleneimine) (PEI) with p-xylylene dichloride (XDC) and then quaternized with methyl iodide to form a perpetually positively charged layer. In order to improve the efficiency of nanofiltration membrane, the concentration of PEI, XDC and methyl iodide solutions, PEI coating and cross-linking time have been optimized. As a result, a high water flux and high $CaCl_2$ rejection (1,000 ppm) was obtained for the composite membrane with values of $18.29L/m^2.h$ and 93.62% at 4 bar and $25^{\circ}C$, respectively. The rejections of NF membrane for different salt solutions followed the order of $Na_2SO_4$ < $MgSO_4$ < NaCl < $CaCl_2$. Molecular weight of cut off (MWCO) was calculated via retaining of PEG solutions with different molecular weights that finally, it revealed the Stokes and hydrodynamic radius of 1.457 and 2.507 nm on the membrane selective layer, respectively. The most efficient positively charged nanofiltration membrane exhibited a $Ni^{2+}$ rejection of 96.26% for industrial wastewater from Shamse Hadaf Co. (Kashan, Iran).

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 추계학술대회
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• pp.421-424
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• 2006

Nafion/Pt/Polypyrrole composite membranes were fabricated by chemical in-situ polymerization of pyrrole monomers with Pt precursors in Nafion matrix for DMFC. We demonstrated that positively charged pyrrolinum groups of polypyrrole particles were co-interacted with sulfonic groups of Nafion as verified by FT-IR results. Mutual interaction between $Nafion-SO_3^-$ (or negatively charged Pt precursors) and Polypyrrole$-NH_2^+$ influenced the physical properties of pristine Nafion. Thermal property proton conductivity, methanol permeability, and cell performance of pristine and modified Nafion were analyzed for an application of DMFC membrane. Thermal stabilities of sulfonic groups and side chains in Nafion/Pt/polypyrrole composite membranes were higher than those of Nafion due to mutual interaction between sulfonic groups of Nafion and pyrrolinum groups of polypyrrole. Methanol permeabilities of Nafion/Pt/Polypyrrole composite were reduced more proton conductivities with the increase in the content of Pt particles. As a result of that, the enhancement of cell performance by Nafion/Pt/Polypyrole O2 relative to Nafion was more pronounced under the specific experimental condition such as high temperature and more concentrated methanol solution.

• 멤브레인
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• 제15권1호
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• pp.34-43
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• 2005

Poly(vinyl alcohol) (PVA)이 폴리술폰 한외여과 막, 술폰화된 폴리에테르술폰, 폴리아미드 나노 막 위에 코팅된 나노 복합막을 가압법에 의해서 제조되었다. PVA는 글루터알데하이드 수용액으로 가교되었다. 모든 지지층위에 PVA 희박용액이 성공적으로 코팅되어 나노복합막이 제조되었다. 지지막 위의 친수화도가 높아짐에 따라 수투과 유량이 증가하였다. 특히 음하전을 띠는 폴리아미드 나노 복합막의 제타전위는 PVA로 코팅함으로서 감소되었다. 막 오염 실험은 양이온을 띠는 계면활성제, 휴민산, 휴민산과 칼슘이온 복합체 및 bovine serum albumin을 사용하여 실행하였다. PVA로 코팅되지 않은 폴리아미드 나노복합막은 각각의 오염물질에 의해서 심하게 오염되었다. 휴민산과 단백질에 의한 오염은 오염물질의 등전점에서 가장 심하게 발생하였다. 휴민산에 이가 양이온을 첨가함으로서 오염이 심각하게 일어났다. PVA 수용액으로 폴리아미드 나노 복합막을 코팅함으로서 막 오염이 감소되었다. PVA로 코팅된 폴리아미드 나노 복합막은 산, 염기용액에 대해 저항성을 보였다.

• 한국막학회:학술대회논문집
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• 한국막학회 2004년도 추계 총회 및 학술발표회
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• pp.139-141
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• 2004