• 한국산학기술학회논문지
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• 제17권1호
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• pp.433-440
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• 2016

설폰화시킨 poly(etheretherketone)(sPEEK)막의 전해질 특성을 향상시키기 위하여 sPEEK에 imidazole과 무기물인 phosphotungstic acid(PWA)를 첨가하고 용액주조법을 이용하여 복합막을 제조하였다. TGA분석을 통하여 산-염기 상호작용에 의한 물리적 가교결합이 복합막의 설폰산그룹 분해에 대한 열저항성을 향상시키고 PWA의 첨가는 복합막의 열분해에 대한 저항성을 향상시키는 것을 확인할 수 있었다. 산-염기 상호작용은 sPEEK/imidazole 복합막의 함수율과 양이온전도도 및 메탄올 투과도를 감소시켰는데 이것은 물리적 가교결합이 복합막을 견고하게 만들기 때문이다. PWA는 sPEEK/imidazole/PWA 복합막의 함수율과 메탄올 투과도는 감소시켰지만 양이온전도를 향상시켰다. 따라서 PWA는 복합막의 선택도를 향상시키는 효과를 나타내었다.

• 한국막학회:학술대회논문집
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• 한국막학회 1996년도 춘계 총회 및 학술발표회
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• pp.62-64
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• 1996

Chitin, which is obtained mainly from the cuticle of a marine crustacean, has recently aroused great interest in its industrial and biomedical applications. Chitosan, deacetylated form of chitin, appears to be more useful for biomedical application and dehydration of aqueous solutions than chitin, since it has both hydroxyl and amino groups that can be modified easily. Amino groups on chitosan reacts with dialdehyde to form a Schiff base and then crosslinked, and can be easily neutralized with sulfuric acid and metal ions. Polyfunctional metal ions can form a metal-polyelectrolyte complexes with chitosan. Membranes used in modules so far working in industrial pervaporation plants are generally of composite type. This composite membrane was prepared by coating a porous polysulfone ultrafiltration membrane support of definite structure with a thin, dense layer of permselective chitosan. To apply industrial scale pervaporation process for dehydration of aqueous ethanol and isopropanol, chitosan composite membranes were prepared and tested at various conditions.

• 한국수소및신에너지학회논문집
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• 제28권2호
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• pp.144-149
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• 2017

A proton-conducting bisphenylpropaned sulfonated fluorinated blockcopolymer (BPSFBC) was synthesized. Five kinds of polymer electrolyted composite membranes were preparated by incorporating silica ($SiO_2$) with various weight ratio. And their characteristics were investigated by FT-IR (fourier transform infrared), $^1H-NMR$ ($^1H$ nuclear magnetic resonance), TGA (thermogravimetric analysis), water uptake, FE-SEM (field emission scanning electron microscopes), and ion conductivity properties. The water uptake and ion conductivity were increased until 9 wt% $SiO_2$, and then decreased. The maximum proton conductivity equal to $52mScm^{-1}$ was measured for the BPSFBC/$SiO_2$-9 composite membrane at $90^{\circ}C$ and 100% relative humidity. From the measured results, it is distinct that the manufactured composite membrane BPSFBC/$SiO_2$-9 can be considered as a polymer membrane suitable for a fuel cell electrolyte.

• 한국수소및신에너지학회논문집
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• 제28권4호
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• pp.338-344
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• 2017

Polyoxometal molybdophosphoric acid (MoPA) bonded polyether ether ketone (PEEK) composite membrane for water electrolysis has been investigated. The composited membrane, covalently cross linked (CL) sulfonated polyether ether ketone (SPEEK) with a bonded MoPA, was prepared in sulfonation of PEEK, cross linkage reaction with 1,4-diiodobutane, and addition with MoPA. PEEK was covalently cross-linked with 1,4-diiodobutane to improve mechanical strength and was added with MoPA to increase proton conductivity. MoPA should be fixed to back bone of SPEEK to prevent bleeding out. Therefore, the carbonyl group of SPEEK was reduced with NaBH4 and 3-isocyanatepropyltriethoxysilane (ICPTES) was added. The MoPA bonded composite was produced in the reaction of MoPA with 3-mercaptopropyltrimethoxvsilane (MPTMS). In conclusion, MoPA bonded CL-SPEEK composite membrane featured 0.129 S/cm of proton conductivity at $80^{\circ}C$, and 2,156 hours of chemical stability in Fenton test. These properties are better than those of membranes of other SPEEK system.

• 한국생산제조학회지
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• 제6권2호
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• pp.49-58
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• 1997

The objective of this study is to investigate effects of prebuckling on the bucking of laminated compostie cylindrical shells, Both axial compression and lateral pressure are considered for laminated composite cylindrical shells with length to radius ratios. The shell walls are made of a laminate with several symmetric ply orientations. The study was using finite difference energy method, utilizing the nonlinear bifurcation branch with nonlinear prebuckling displacements. The results are compared to the buckling loads determined when membrane prebuckling displacements are considered.

• Membrane and Water Treatment
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• 제1권3호
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• pp.193-206
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• 2010

Organic fouling and biofouling pose a significant challenge to the membrane filtration process. Photocatalysis-membrane hybrid system is a novel idea for reducing these membranes fouling however, when $TiO_2 photocatalyst nanoparticles are used in suspension, catalyst recovery is not only imposes an extra step on the process but also significantly contributes to increased membrane resistance and reduced permeate flux. In this study, $TiO_2$ photocatalyst has been immobilized by coating on the microfiltration (MF) membrane surface to minimize organic and microbial fouling. Nano-sized $TiO_2$ was first synthesized by a sol-gel method. The synthesized $TiO_2$ was coated on a Poly Vinyl Difluoride (PVDF) membrane (MF) surface using spray coating and dip coating techniques to obtain hybrid functional composite membrane. The characteristics of the synthesized photocatalyst and a functional composite membrane were studied using numerous instruments in terms of physical, chemical and electrical properties. In comparison to the clean PVDF membrane, the $TiO_2$ coated MF membrane was found more effective in removing methylene blue (20%) and E-coli (99%).

• 한국막학회:학술대회논문집
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• 한국막학회 2003년도 추계 총회 및 학술발표회
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• pp.157-159
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• 2003

• 한국막학회:학술대회논문집
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• 한국막학회 1999년도 춘계 총회 및 학술발표회
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• pp.78-80
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• 1999

• 한국막학회:학술대회논문집
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• 한국막학회 2000년도 춘계 총회 및 학술발표회
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• pp.77-78
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• 2000

• 한국막학회:학술대회논문집
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• 한국막학회 2000년도 춘계 총회 및 학술발표회
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• pp.89-92
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• 2000