Abstract
A crack‐free silica composite membrane has been synthesized from a nanoparticulate silica sol (particle diameter 2 through the silica membrane layer after heat treatment at 200°C is about 4.9 × 10−12 mol·m/m2·s· Pa, and the mechanism of gas transport is Knudsen flow. The thermal stability of the silica composite membrane is excellent up to 500°C.