Expeditious calcination of inorganic membranes by an instant temperature increment

Abstract

Rapid thermal treatments potentially allow for a significant reduction in production time of ceramic multilayered membranes, in turn aiding increased industrial application of these membranes and accelerating research on their development. Two methods are proposed for the rapid thermal treatment of thin supported inorganic membrane films. Both methods involve an instant increment in temperature imposed on the membrane. In the first method, the instant temperature step is enforced by placing the membrane in a preheated environment; in the second method, the membrane is placed directly onto a hot plate. The proposed methods can be used for a diverse range of materials. Mesoporous γ-alumina and microporous silica have been selected as model membrane materials. Both rapid heating methods require ∼20 min to yield mesoporous γ-alumina membranes that are comparable to membranes made via conventional calcination (∼1 day). Selective silica membranes have been obtained after 1 h exposure to an environment of 400 or 600 °C, and after 1 h contact with a hot plate of 550 °C (compared to up to 2 days for conventional calcination). The results indicate that, although prevention of contaminations needs continuous attention, both methods proposed for rapid heat treatment can reduce cost and time in ceramic membrane production.