Ceramic membrane elaboration using supercritical fluid

Macroporous alumina supports were prepared from commercial δ-Al2O3 and modified by hydrolytic decomposition of titanium isopropoxide in supercritical propan-2-ol. Various experimental parameters were studied in relation to the deposition of TiO2 particles on the substrate surface and inside the pores: temperature, precursor concentration, water-to-alkoxide ratio, solution flow rate, and deposition time. A set of these parameters was found to allow supported membranes with high nitrogen permeation (9.5 × 10−6 mol·m−2·s−1·Pa−1 ) and low average pore radius (1.5 nm) to be obtained.