Microporous molecular separation membrane with high hydrothermal stability

摘要

A hydrothermally stable, microporous organic-inorganic hybrid membrane based on silica, having an mean pore diameter of between 0.2 and 1.5 nm, is characterised in that between 5 and 40 mole% of the Si-O-Si bonds have been replaced by mo ieties having the one of the formulas: Si-{[CH()X]-Si-}, Si-[CH()X]-Si or Si-CH-Si{(CH)-Si-} in which m = 1-8, n = 2m, 2m-2, 2m-4, 2m-6 or 2m-8; provided that n≥2, X = H or (CH)Si, p = 0 or 1, and q = 1, 2, 3 or 4. The membrane can be produced by acid-catalysed hydrolysis of suitable bis- silane precursors such as bis(trialkoxysily)alkanes, preferably in the presence of monoorganyl-silane precursors such as trialkoxy-alkylsilanes.