A hydrostable mesoporous γ-Al2O3 membrane modified with Si–C–H organic-inorganic hybrid derived from polycarbosilane

Abstract Excellent hydrophobicity of polycarbosilane (PCS)-derived Si–C–H organic-inorganic hybrid was characterized by measuring water vapor adsorption-desorption isotherms at room temperature. Modification with the PCS-derived Si–C–H successfully improved hydrostability in terms of stable gas permeation property of sol gel-derived hydrophilic mesoporous γ-Al2O3 membrane formed on a macroporous α-Al2O3 support: even under saturated water vapor partial pressure at 50 °C, the modified membrane exhibited high gas permeances of helium, hydrogen and nitrogen ranging from 1.2 to 3.0 × 10−6 mol m−2 s−1·Pa−1. The improved gas permeability under the humid condition achieved for the Si–C–H-modified mesoporous γ-Al2O3 membrane in this study was discussed aiming to prepare a gas permeable hydrophobic mesoporous intermediate layer essential for developing H2-permselective ceramic-based multilayered composite membranes with applications to novel solar hydrogen production system.