Preparation and Hydrothermal Stability of Organic-inorganic Hybrid Silica Membrane

doi:10.3724/SP.J.1077.2010.00758

Abstract

Abstract:

A new organic-inorganic hybrid microporous membrane was prepared via Sol-Gel method with bridged silsesquioxane (1, 2-bis(triethoxysilyl)ethane, BTESE) as a precursor. Macroporous α-Al₂O₃disk supported mesopo- rous γ-Al₂O₃ layer was used as support. Defect-free hybrid silica membrane was deposited on such support by using a stable nano-sized sol and subsequently calcining in pure nitrogen atmosphere. The hybrid SiO₂ membrane as well as the powder was characterized by TG/DSC, BET and gas permeation. The hybrid silica membranes exhibit molecular sieve properties for small gases like He, CO₂, O₂, N₂, CH₄, and SF₆ with helium permeance in the range of (1.0-3.5)´10^-7mol/(m²·s·Pa)(at 200℃, 0.3MPa). Considering the membrane calcined at 500℃, it is found that the permselectivity of the He (0.255nm) with respect to CO₂(0.33nm) is 47, which is much higher than the corresponding Knudsen value (He/CO₂=3.3). Effect of calcination temperature on hydrothermal stability of those microporous membranes was studied in detail. Results show that the performances of hybrid SiO₂ membranes calcined at 450℃, 500℃ and 550℃ deteriorate under a H₂O partial pressure of 200, 500 and 1000kPa, respectively.

Key words: microporous ceramic membrane, hybrid organic-inorganic SiO₂membrane, hydrothermal stability, gas separation

CLC Number:

O484

QI Hong, HAN Jing, JIANG Xiao-Luo, XING Wei-Hong, FAN Yi-Qun. Preparation and Hydrothermal Stability of Organic-inorganic Hybrid Silica Membrane[J]. Journal of Inorganic Materials, 2010, 25(7): 758-764.

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