• Title/Summary/Keyword: ceramic membranes

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The Synthesis and Pore Property of Hydrogen Membranes Derived from Polysilazane as Inorganic Polymer (무기 고분자인 폴리실라잔을 이용한 수소 분리막의 합성 및 기공특성)

  • Kwon, Il-Min;Song, In-Hyuck;Park, Young-Jo;Lee, Jae-Wook;Yun, Hui-Suk;Kim, Hai-Doo
    • Journal of the Korean Ceramic Society
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    • v.46 no.5
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    • pp.462-466
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    • 2009
  • We investigated the pore properties of inorganic membranes applied for hydrogen separation industry. Inorganic membranes were derived from polysilazanes. The thermal reactions involved were studied using thermogravimetry(TG) and IR spectroscopy(FTIR) of the solids. To determine the thermal effect of pore properties, polysilazanes were pyrolysed in inert atmosphere. Pore volume and BET surface area showed the maximum value at a pyrolysis temperature of $500^{\circ}C$. For amorphous SiCN membrane derived from polysilazanes, selectivity of $H_2/N_2$ was 4.81 at $600^{\circ}C$.

Characteristics of Alumina-Supported TiO2 Composite Ultrafiltration Membranes Prepared by the Sol-Gel Method (Sol-Gel 법으로 제조한 알루미나 담체의 $TiO_2$ 복합 한외여과막의 특성)

  • 현상훈;최영민
    • Journal of the Korean Ceramic Society
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    • v.29 no.2
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    • pp.107-118
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    • 1992
  • Alumina supports for TiO2 ultrafiltration membrane coating were prepared by presintering disk-type preforms at 140$0^{\circ}C$. These supports showed uniform microstructures which had the apparent porosity of 40%, the pore size distribution in the range of 0.1~0.5${\mu}{\textrm}{m}$, and the water flux of 1400ι/$m^2$.h at the pressure difference of 10 atm. The optimum pH and concentration of the TiO2 sol for coating were 0.8 and 1.0 wt%, respectively, and sol particles were identified as rutile forms of 20 nm size. Crack-free alumina-supported rutile TiO2 membranes could be prepared through well controlled drying and heating the gel layer coated by the sol-gel dipping. The pore size of the TiO2 membranes heat-treated at 50$0^{\circ}C$ for 2 hrs was 30~80$\AA$, and their thickness varied from 1.1 to 3.8 ${\mu}{\textrm}{m}$ in accordence with the dipping time (4~40 min). The flux of water through this composite membrane at 10 atm was found to be in the range from 800 to 1100ι/$m^2$.hr depending on the dipping time (10~40 min). The membrane thickness increased linearly with the square root of the dipping time and the slope was 0.62 ${\mu}{\textrm}{m}$/{{{{ SQRT { min} }}.

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Photocatalytic Membrane Reactor for VOC Decomposition Using Pt-Modified Titanium Oxide Membranes

  • Toshinori Tsuru;no, Takehiro-Kan;Tomohisa Yoshioka;Masashi Asaeda
    • Proceedings of the Membrane Society of Korea Conference
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    • 2004.05a
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    • pp.39-42
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    • 2004
  • Ceramic membranes have attracted a great attention because they have excellent resistance to most organic solvents and can be used over a wide temperature range. Especially, titania (titanium oxide, TiO$_2$) shows excellent chemical resistance and can be used both acidic and alkali solutions, and therefore, titania is one of the most promising materials for the preparation of porous membranes; titania membranes having pore sizes in the range of nanofiltration (NF) to ultrafiltration (UF) membrane have been prepared by the sol-gel process (Tsuru 2001).(omitted)

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Microstructural Change of Doped-Alumina Membrane (도핑된 알루미나 여과막의 미세구조 변화)

  • 이진하;최성철;한경섭
    • Journal of the Korean Ceramic Society
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    • v.36 no.10
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    • pp.1040-1047
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    • 1999
  • After alumina sol was prepared by Yoldas process supported membranes were fabricated by adding ce and Re solution and SiO2 sol into alumina sol. The particle size of alumina sol was 11 nm and it was monodispersed transparent and stable for long time. The pore size of un-doped membrane started to increase to about 7,5nm at 1000$^{\circ}C$ and it was grown to twice (about 15nm) at 1100$^{\circ}C$ However the pore size of doped alumina was uniform to 1100$^{\circ}C$. The effect of retardation of grain growth was superior in SiO2 addition to that of Ce and Ru Because SiO2 doped samples transformed to needed-like phase and densified at 1200$^{\circ}C$ their application in membranes was limited. Ce and Ru doped sample showed vermicular structure identical to the un-doped ones at 1200$^{\circ}C$ But the particle size was smaller than that of un-doped ones.

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Preparation of Microporous Glasses by the Phase-Separation Technique and Their Salt-Rejection Characteristics (상분리법에 의한 다공질유리의 제조 및 탈염특성)

  • 현상훈;김계태
    • Journal of the Korean Ceramic Society
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    • v.23 no.5
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    • pp.93-101
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    • 1986
  • Microporous glasses were prepared from the 50 $SiO_2-44$ $B_2O_3-6$ $Na_2O$(wt%) parent glass by the phase eparation technique and were characterized by SEM, BET, and Gas Adsorption methods to investigate the possiblity of their use as salt-rejection membranes for reverse osmosis. The conditions of the phase separation for the possible glass membranes were optimized for the given parent glass. The temperature and duration of heat-treatment were desired to be lower(853K) and shorter (1/2~1 hr) respectively. The specific surface areas of porous glasses prepared in this study were about 80~120$m^2$/g and their pore size distribution had a unimodal shape(peak pore radius less than 15$\AA$) It was suggested that the porous glass obtained in this work could be effective for salt-rejection in point of pore size distributions but the way to increase its surface area for the high flux must be studied.

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Preparation and Hydrogen Permeability of SiC-Y2O3 Composite Membranes

  • Son, Boyoung;Jung, Miewon
    • Journal of the Korean Ceramic Society
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    • v.50 no.6
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    • pp.495-497
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    • 2013
  • SiC-$Y_2O_3$ porous composites were fabricated using $Y_2O_3$ powders synthesized by sol-gel process to control physical and thermo-chemical properties. $Y_2O_3$ powders were mixed with SiC powders by co-pressing with HPCS (hydridopolycarbosilane) binder at moderate temperature. The properties of membranes were characterized by XRD, FE-SEM, and BET surface analysis. Hydrogen permeability was performed at various temperatures.