ZrO(2) and TiO(2) membranes for nanofiltration and pervaporation - Part 2. Development of ZrO(2) and TiO(2) toplayers for pervaporation

摘要

This paper reports the preparation of novel ZrO(2) and TiO(2) membrane layers with a tight pore structure for pervaporation applications, a high thermal and a high chemical stability. Optimized alpha-Al(2)O(3)/gamma-Al(2)O(3)/ZrO(2) and (alpha-Al(2)O(3)/gamma-Al(2)O(3)/TiO(2) multilayer membranes, having a toplayer with a thickness 50-100 nm, were found defect-free in permporometry and displayed a high selectivity in standard pervaporation tests with alcohol/water mixtures. Separation tests at 70 degrees C demonstrated a separation factor exceeding 300 for a 95/5-wt IPA/water mixture for both membranes. For the membrane with ZrO(2) toplayer, the membrane quality was further demonstrated by applying ethanol/water as a feed mixture (separation factor > 150). (c) 2008 Elsevier B.V. All rights reserved.