SCI和EI收录∣中国化工学会会刊

›› 2011, Vol. 19 ›› Issue (3): 404-409.

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Preparation of Composite Microporous Silica Membranes Using TEOS and 1,2-Bis(triethoxysilyl)ethane as Precursors for Gas Separation

漆虹   

  1. Membrane Science and Technology Research Center, State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing University of Technology, Nanjing 210009, China
  • 收稿日期:2010-08-13 修回日期:2011-01-29 出版日期:2011-06-28 发布日期:2011-06-28
  • 通讯作者: QI Hong, E-mail: hginjut@yahoo.com.cn
  • 基金资助:
    Supported by the National Natural Science Foundation of China(20906047);the State Key Laboratory of Chemical Engineering(SKL-ChE-09A01);the State Key Laboratory of Materials-Oriented Chemical Engineering(ZK201002)

Preparation of Composite Microporous Silica Membranes Using TEOS and 1,2-Bis(triethoxysilyl)ethane as Precursors for Gas Separation

QI Hong   

  1. Membrane Science and Technology Research Center, State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing University of Technology, Nanjing 210009, China
  • Received:2010-08-13 Revised:2011-01-29 Online:2011-06-28 Published:2011-06-28
  • Supported by:
    Supported by the National Natural Science Foundation of China(20906047);the State Key Laboratory of Chemical Engineering(SKL-ChE-09A01);the State Key Laboratory of Materials-Oriented Chemical Engineering(ZK201002)

摘要: This paper reports on a new microporous composite silica membrane prepared via acid-catalyzed polymeric route of sol-gel method with tetraethylorthosilicate(TEOS)and a bridged silsesquioxane[1,2-bis(triethoxysilyl)ethane, BTESE]as precursors.A stable nano-sized composite silica sol with a mean volume size of 5 nm was synthesized. A 150 nm-thick defect-free composite silica membrane was deposited on disk support consisting of macroporous α-Al2O3 and mesoporousγ-Al2O3 intermediate layer by using dip-coating approach,followed by calcination under pure nitrogen atmosphere.The composite silica membranes exhibit molecular sieve properties for small gases like H2,CO2,O2,N2,CH4 and SF6 with hydrogen permeances in the range of(1-4)×10-7mol·m-2·s-1·Pa-1 (measured at 200℃,3.0×105Pa).With respect to the membrane calcined at 500℃,it is found that the permselectivities of H2(0.289 nm)with respect to N2(0.365 nm),CH4(0.384 nm)and SF6(0.55 nm)are 22.9,42 and>1000,respectively, which are all much higher than the corresponding Knudsen values(H2/N2=3.7,H2/CH4=2.8,and H2/SF6=8.5).

关键词: tetraethylorthosilicate, 1,2-bis(triethoxysilyl)ethane, composite silica membranes, gas separation, molecular sieving

Abstract: This paper reports on a new microporous composite silica membrane prepared via acid-catalyzed polymeric route of sol-gel method with tetraethylorthosilicate(TEOS)and a bridged silsesquioxane[1,2-bis(triethoxysilyl)ethane, BTESE]as precursors.A stable nano-sized composite silica sol with a mean volume size of~5 nm was synthesized. A 150 nm-thick defect-free composite silica membrane was deposited on disk support consisting of macroporous α-Al2O3 and mesoporousγ-Al2O3 intermediate layer by using dip-coating approach,followed by calcination under pure nitrogen atmosphere.The composite silica membranes exhibit molecular sieve properties for small gases like H2,CO2,O2,N2,CH4 and SF6 with hydrogen permeances in the range of(1-4)×10-7mol·m-2·s-1·Pa-1 (measured at 200℃,3.0×105Pa).With respect to the membrane calcined at 500℃,it is found that the permselectivities of H2(0.289 nm)with respect to N2(0.365 nm),CH4(0.384 nm)and SF6(0.55 nm)are 22.9,42 and>1000,respectively, which are all much higher than the corresponding Knudsen values(H2/N2=3.7,H2/CH4=2.8,and H2/SF6=8.5).

Key words: tetraethylorthosilicate, 1,2-bis(triethoxysilyl)ethane, composite silica membranes, gas separation, molecular sieving