• Title/Summary/Keyword: silica membrane

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Stability of a Silica Membrane in the HI-$H_2O$ Gaseous Mixture (HI-$H_2O$ 기상 혼합물에서 Silica 막의 안정성)

  • HWANG Gab-Jin;PARK Chu-Sik;LEE Sang-Ho;Choi Ho-Sang
    • Membrane Journal
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    • v.14 no.3
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    • pp.201-206
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    • 2004
  • The stability of the prepared silica membrane by chemical vapor deposition (CVD) method in the HI-$H_2O$ gaseous mixture was evaluated aiming at the application for hydrogen iodide decomposition in the thermochemical IS process. Porous $\alpha$-alumina having pore size of 100 nm was modified by the different CVD temperature using tetraethoxysilane as the Si source. The CVD temperature was $700^{\circ}C$, $650^{\circ}C$, and $600^{\circ}C$. The $H_2$/H$_2$ selectivities of the modified membranes which were measured by single-component permeation experiment showed 43.2, 12.6, and 8.7 at $600^{\circ}C$ for the M1 (CVD temperature was $700^{\circ}C$), M2 (CVD temperature was $650^{\circ}C$) and M3 membranes (CVD temperature was $600^{\circ}C$), respectively. Stability experiment in the HI-$H_2O$ gaseous mixture was carried out at $450^{\circ}C$. The prepared silica membrane at $600^{\circ}C$ of CVD temperature was more stable than that at the other CVD temperature.

Preparation and Permeation Characteristics of PTMSP-PDMS-Silica/PEI Composite Membranes (PTMSP-PDMS-Silica/PEI 복합막의 제조 및 투과특성)

  • Lee, Hyun-Kyung;Hong, Se-Lyung
    • 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.

PVA/Silica Hybrid Membrane Containing Sulfonic Acid Croup for Direct Methanol Fuel Cells Application (Sulfonic acid group을 갖는 PVA/Silica Hybrid막의 DMFC 응용)

  • Young Moo Lee;Dae Sik Kim;Kwang Ho Shin;Ho Bum Park;Ji Won Rhim
    • Membrane Journal
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    • v.13 no.2
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    • pp.101-109
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    • 2003
  • In the present study, crosslinked poly(vinyl alcohol) (PVA) membranes were prepared at various crosslinking agent content using sulfosuccinic acid (SSA) containing sulfonic acid group ($SO_3H)$. To reduce methanol permeability, silica was introduced to the membrane using sol-gel process. The hybrid membranes were studied in relation to proton conductivity and methanol permeability. It was found that both these properties were very dependent on the effect of SSA content as a crosslinking agent and as a donor of hydrophilic $SO_3H)$ group. The proton conductivities of these PVA/SSA/Silica membranes are in the range from $10^{-3}\;to\;10^{-2}$S/cm and the methanol permeabilities are in the range from $10^{-8}\;to\;10^{-7}\;cm^2/sec$.

Preparation of Polysulfone Composite Ultrafiltration Hollow Fiber Membranes Incorporating Nano-size Fumed Silica with Enhanced Antifouling Properties (나노 크기의 Fumed Silica가 함유된 Polysulfone 한외여과 중공사막 제조 및 내오염성 분석)

  • Kang, Yesol;Lim, Joohwan;Kim, In S.
    • Membrane Journal
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    • v.28 no.6
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    • pp.379-387
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    • 2018
  • This study was conducted to improve the membrane characteristics and performance by increasing hydrophilicity by adding additives to the ultrafiltration polysulfone (PSf) hollow fiber membrane. The mixed matrix membranes (MMMs) were prepared by dispersing 15 nm of fumed silica (FS) in the spinning solution at 0.1, 0.3 and 0.5 wt%. SEM analysis was carried out to confirm the cross-section and surface condition. It was confirmed that mean pore radius of the hollow fiber increased by 4 nm as FS was added. In addition, contact angle measurement was carried out for the hydrophilicity analysis of hollow fiber membranes, and it was confirmed that the hydrophilicity of MMMs were increased by adding of FS. In the case of water permeability, the membrane including FS showed 91~96 LMH and showed 5~11% more increase than PSf membrane. In the antifouling performance test, relative flux reduction ratios of FS mixed hollow fiber membranes were lower than that of PSf membranes, and it was confirmed that increase of hydrophilicity hinders adsorption of hydrophobic BSA on the membrane surface.