• Membrane Journal
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• v.30 no.1
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• pp.30-37
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• 2020

Polymer/inorganic composites were used as a protective layer of lihitum metal electrode for effective suppression of lithium dendrite. PVDF-HFP was used as an polymer material and TiO₂ nanoparticle was used as an inorganic material. PVDF-HFP is a highly flexible polymer that acts as a matrix of inorganic materials while TiO₂ nanoparticle improves the mechanical strength and ion conductivity of the protective layer. The as-synthesized protective hybrid membrane exhibited good dispersion of TiO₂ in the PVDF-HFP matrix by SEM, AFM and XRD analyses. Furthermore, the electrochemical analysis showed that the polymer-inorganic composite retained high coulombic efficiency of 80% and low overpotential, less than 20 mV until the 100^th cycles due to the improved mechanical properties and ion conductivity in comparison to the control sample (untreated and PVDF-HFP polymers/Cu).

• Transactions of the Korean hydrogen and new energy society
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• v.28 no.2
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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.

• Proceedings of the Membrane Society of Korea Conference
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• 2005.11a
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• pp.204-207
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• 2005

• Journal of the Korean Electrochemical Society
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• v.7 no.2
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• pp.89-93
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• 2004

Sulfonated polysulfone (SPSF) with poly(phenylmethyl silsesquioxane, PPSQ) composite polymer electrolyte membranes were prepared and their proton conductivity, water uptake and methanol permeability of membranes were characterized. By controlling the ratio of $(CH_3)_3SCI\;and\;CISO_3H$ and reaction time, SPSF with $37\~75\%$ degree of sulfonation were synthesized. The increase of sulfonate groups in the base polymer resulted in the increase of the water uptake in the membranes as well as methanol permeability. Composite membranes were prepared by casting of DMF solution of SPSF and PPSQ. The proton conductivity of the composite membrane at room temperature was $2.8\times10^{-3}\~4.9\times10^{-2}S/cm.$ The increase of PPSQ contents in composite membranes resulted in a decrease in water uptake and methanol permeability. Composite membranes containing $5\%$ PPSQ did not make a significant effect on the proton conductivity nO methanol permeability compared with that of pristine SPSF, but a significant decrease of water uptake was observed.

• Proceedings of the Membrane Society of Korea Conference
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• 2004.05a
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• pp.144-147
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• 2004

Organosilicon polymers have long paid attention as functional polymers [1,2]. Among others, poly- (1-trimethylsilyl-1-propyne) [PTMSP] is a polymer, which forms a gas separating membrane with extraordinary high gas permeability. In particular, composite membranes that constituted two different matrices (inorganic and organic) have been recently developed in order to improve the permeation characteristics.(omitted)

• Transactions of the Korean hydrogen and new energy society
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• v.23 no.1
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• pp.34-42
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• 2012

Gas diffusion layers (GDLs) of carbon composite type in polymer electrolyte fuel cells were prepared by simple and cheap manufacturing process. To obtain the carbon composite GDLs, carbon black with polymer binder was mixed in solvent, rolled to make sheet, and finally heat-treated at $340^{\circ}C$. The performance of fuel cell using composite GDLs was changed by PTFE content. The physical properties of composite GDLs for pore, conductivity and air permeability were analyzed to compare with the variation of fuel cell performance. The conductivity of composite GDLs was very similar to carbon paper as commercial GDL but pore properties and air flux were considerably different. The porosity, PTFE content and conductivity for composite GDLs did not have an influence on the cell performance much. The increase of pore diameter and air flux led to enhance cell performance.

• Membrane Journal
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• v.27 no.3
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• pp.284-289
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• 2017

In this study, natural clay as a filler was systematically integrated into polysulfone nanofibers to prepare polysulfone/clay composite membranes with mechanical properties. The composite nanofibers were formed by electrospinning of a mixed precursor of polysulfone and clay. The pore size of the composite membranes was adjusted by simply controlling the number of layers of nanofibers. The overall membrane properties were examined by SEM, contact angle, pore characteristics, tensile strength and water flux. In particular, the presence of clay within the nanofibers was confirmed with SEM images and the mechanical property of the composite nanofiber membranes was examined by tensile strength measurements. Thus, the prepared composite membranes were expected to be utilized for water treatment system.

• Membrane Journal
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• v.18 no.1
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• pp.94-102
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• 2008

For the treatment of the dye wastewater, a polyamide nano-composite membrane and reverse osmosis (RO) membranes were prepared using interfacial polymerization technique, in which piperazine, meta-phenylene diamine, and trimesoyl chloride were used as monomers, Their permselective properties were characterized with aqueous solutions of PEG 600, $Na_2SO_4$, and NaCl, and their performance was compared with that of Osmonics Co, They were found to be a typical nano-composite membrane and a low pressure RO membrane. Using them, a real dye wastewater supplied from the Kyungin Corporation, one of the domestic dye producer, was treated, studying the separation performances of the membranes, Also, during the wastewater treatment, cleaning in place (CIP) of the membranes was carried out regularly to recover the flux of the membranes. Three different chemical cleaners were employed for the CIP process and their performance were compared in this study.

• Membrane and Water Treatment
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• v.10 no.5
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• pp.381-385
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• 2019

Surface modification is very efficient and scalable approach to achieve improved membrane performance. We treated Reverse Osmosis Thin Film Composite (TFC RO) membrane with various concentrations of Polyethylene Glycol (PEG), a hydrophilic polymer after activation with sodium hypochlorite. This treatment resulted in an increment of the water flux by 43% and the salt rejection by 2.36% for the 3000 mg/l PEG-treated membrane. Further, these PEG-treated membranes were exposed to a mixture of 3000 mg/l PEG and 1000 mg/l sodium hypochlorite for 1 hour. Further modification of this membrane by PEG and sodium hypochlorite mixture increased the water permeance up to 133% when compared with the virgin TFC RO membrane. We characterized the treated membranes to understand the changes in wettability by contact angle analysis, changes in surface morphology and roughness by scanning electron microscope (SEM) and atomic force microscope (AFM) analysis.

• Membrane Journal
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• v.26 no.1
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• pp.14-25
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• 2016

The membrane separation process is growing very fast because of the high efficiency and low cost compared with other traditional process. The membrane process consists of various components such as membrane, module and mechanical part. The requirements for materials used in the membrane separation are becoming more and more demanding for achievement of high efficiency. Membrane module is also considered as the one of the key component in the membrane system. Recently composite materials have been considered as the membrane housing due to their excellent property and low cost compared with stainless module. In this review, a various types of glass fiber and composite material are summarized and their potential for the application of membrane system is discussed.