• Membrane Journal
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• v.20 no.1
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• pp.47-54
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• 2010

The PDMS-NaYzeolite composite membranes were prepared by adding 1~40 wt% NaYzeolite to PDMS. In order to investigate the characteristics of these membranes, we used the analytical methods such as FT-IR, $^1H$-NMR, and SEM. The permselectivity of $H_2$ and $N_2$ gases through the composite membranes was studied as a function of NaYzeolite contents. The permeability and selectivity ($H_2/N_2$) of PDMS membrane increased as the gas permeation pressure increased. The permeability of the PDMS-NaYzeolite composite membranes increased when 1~10 wt% NaYzeolite was added, and then decreased at higher wt% as NaYzeolite content increased. The selectivity ($H_2/_2$) of PDMS-NaYzeolite composite membranes decreased when 1~2 wt% NaYzeolite was added, and then increased as NaYzeolite content increased. As the $H_2$ permeability increased, the selectivity ($H_2/N_2$) of PDMS-NaYzeolite composite membranes decreased at 0~2 wt% and 10~40 wt% NaYzeolite contents, increased at 2~10 wt% NaYzeolite content.

• Membrane Journal
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• v.22 no.5
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• pp.342-351
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• 2012

In this study, PTMSP[poly(1-trimethylsilyl-1-propyne)]/PDMS[poly(dimethylsioxane)]-NaY zeolite and PTMSP/PDMS-NaA zeolite composite membranes were made to incorporate zeolite into PTMSP/PDMS graft copolymer in order to improve the selectivity and thermal stability, the drop of permeability by physical aging effect during long period of time for the PTMSP membrane. To investigate the physico-chemical characteristics of composite membranes, the analytical methods such as FT-IR, $^1H$-NMR, TGA, SEM, and GPC have been utilized. The gas permeability and selectivity properties of $H_2$ and $N_2$ were evaluated. The permeability of the PTMSP/PDMS-NaY zeolite and PTMSP/PDMS-NaA zeolite composite membranes than PTMSP/PDMS graft copolymer membrane increased, increased as zeolite content increased. On the contrary, the selectivity ($H_2/N_2$) of the composite membranes decreased as zeolite content increased. PTMSP/PDMS-NaA zeolite composite membrane showed better permeability and separation factor than PTMSP/PDMS-NaY zeolite composite membrane.

• Membrane Journal
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• v.25 no.3
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• pp.295-300
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• 2015

PDMS-NaA zeolite membranes were prepared by adding 0~40 wt% NaA zeolite. Based on SEM observation, NaA zeolite was dispersed in the PDMS-NaA zeolite membranes with $2{\sim}5{\mu}m$. The permeabilities of $H_2$ and $N_2$ gases through PDMS-NaA zeolite membranes increased as NaA zeolite contents increased and $H_2$ gas had better permeabilities than $N_2$. The selectivity ($H_2/N_2$) of PDMS-NaA zeolite membranes increased as NaA zeolite contents increased.

• Membrane Journal
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• v.23 no.6
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• pp.418-424
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• 2013

The PDMS-chitosan composite membranes were prepared by addition of 0.02~0.60 wt% chitosan to PDMS. In order to investigate the characteristics of these membranes, we used the analytical methods such as SEM and TGA. Gas permeation experiments was performed in $30^{\circ}C$, $4kg/cm^2$, the permeability and selectivity of $H_2$ and $N_2$ according to content change in composite membrane were investigated. The permeability of $H_2$ and $N_2$ for the PDMS-chitosan composite membranes increased when 0~0.20 wt% chitosan was added, and then decreased at higher wt% as chitosan content increased. The selectivity ($H_2/N_2$) of PDMS-chitosan composite membranes decreased when 0~0.20 wt% chitosan was added, and then increased as chitosan content increased. In the case of PDMS-chitosan in which chitosan was inserted to PDMS, thermal stability of PDMS was enhanced. Based on SEM observation, as the chitosan content within PDMS increased, the surface of the composite membranes became coarse and began to form holes.

• Membrane Journal
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• v.18 no.2
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• pp.146-156
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• 2008

In this study, PTMSP of high permeability and high molecular weight was synthesized, and PTMSP-PDMS graft copolymer was synthesized from poly [1-(trimethylsily)propyne] (PTMSP) and hydroxy-terminated poly(dimethylsiloxane) (PDMS). The PTMSP-PDMS-silica composites were prepared by the addition of 15, 30, or 50 wt% tetraethoxysilane (TEOS) to PTMSP-PDMS graft copolymer by sol-gel process. To investigate the physico-chemical characteristics of PTMSP-PDMS-silica/PEI composite membranes, the analytical methods such as $^1H$-NMR, FT-IR, TGA, XPS, GPC, and SEM have been utilized. The gas permeability and selectivity properties of $H_2,\;O_2,\;N_2,\;CO_2,\;CH_4,\;n-C_4H_{10}$, were evaluated. Permeability of the composite membranes increased as TEOS content and pressure increased. Selectivity of $H_2,\;O_2,\;N_2,\;CO_2,\;CH_4,\;and\;n-C_4H_{10}$, showed the maximum value at 30 wt% of TEOS content and decreased thereafter.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.06a
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• pp.599-600
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• 2008

• Membrane Journal
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• v.18 no.3
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• pp.219-225
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• 2008

In this research, polydimethylsiloxane-polymethylmethacrylate (PDMS-PMMA) block copolymer was synthesized from polydimethylsiloxane (PDMS) and methylmethacrylate (MMA) monomer using atom transfer radical polymerization (ATRP). The synthesis characterization of the PDMS-b-PMMA copolymer membrane was carried out by a FT-IR, $^1H$-NMR, GPC and DSC. The permeabilities of nitrogen and hydrogen gases were observed being $1.2{\sim}l.5$ barrer and $6.2{\sim}10.5$ barrer, respectively. Simultaneously, selectivities of hydrogen against nitrogen were $5.3{\sim}6.9$. The permeability and selectivity of PDMS-b-PMMA copolymer membrane were showed lower than the PDMS membrane, but higher than the PMMA membrane.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.8
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• pp.3532-3540
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• 2011

In order to improve flux of PTMSP/PDMS dense membrane, PTMSP/PDMS-PEI composite membrane with PEI support was prepared by phase inversion process and dip coating. These membranes were evaluated in terms of the removal of volatile organic compounds such as PCE, TCE, chloroform, 1,1,1-trichloroethane from wastewater by pervaporation. The selectivity and flux of PTMSP/PDMS dense membranes was in the range of 216.2 to 2394.4 and 244.3 to 428.2g/m2h, respectively. And pervaporation property of PTMSP/PDMS-PEI composite membrane was in the range of 215.5 to 2404.2 and 390.4 to 728.6g/m2h, respectively. PTMSP/PDMS-PEI composite membrane has remarkably greater flux than dense membranes with similar selectivity. It was possible for polymeric membranes used in this study to remove PCE selectively which is dissolved small quantity in water among other separable solutes. PTMSP/PDMS-PEI composite membrane showed the best performances among the silicone polymeric membranes, and has better durability and mechanical strength than dense membranes. PTMSP/PDMS-PEI composite membrane should be a useful candidate for the removal of volatile organic compounds dissolved in wastewater.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.10a
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• pp.37-37
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• 2003

• Journal of Adhesion and Interface
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• v.19 no.4
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• pp.154-162
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• 2018

Plasma treatment and corona treatment have been used for surface modification of polydimethylsiloxane (PDMS) film by activating its surface with the -OH group. Adhesion promoter or coupling agent was also used to improve adhesion of PDMS film with various materials. However, obtained hydrophilicity onto the surface of PDMS films with those processes was transient and vulnerable. In this study, a new alkoxysilane-functionalized acrylic polymer precursor was first synthesized by copolymerization process, and then was reacted with HO-terminated PDMS through condensation reaction to prepare a new surface modifier for PDMS film. The structure and molecular weight of the prepared surface modifier were confirmed by 1H-NMR and GPC measurement. Surface properties of surface modifier-coated PDMS films were also investigated by using XPS, ATR and WCA analysis. The adhesion between the PDMS film and the surface modifier was tested using cross-cut test.