Abstract: Organic/inorganic hybrid separation membranes have been prepared on porous α-Al₂O₃ substrates (pore size, 1—10 μm). The effects of sol synthesis conditions, such as reaction temperature, solvent pH, sol viscosity, n (PTMOS)/ n (TEOS) and n (H₂O)/ n (alkoxide) ratios, on the layer processing and its performance of the resulted membrane were characterized, and an optimum condition of the procedure was achieved. From FTIRspectra, it is found that the crack formation in the membrane is principally related to the structure of the Si—O—Si other than the solvent nature and any other factors. The thickness of the hybrid layer is about₁-2 μm estimated by the SEMimage of cross section. The selectivity of O₂/N₂ and CO₂/N₂ as well as CO₂/O₂ is 2.30, 4.31 and 1.17 respectively, and the permeability is 75.81×10^-17, 75.28× 10^-17 and 72.78×10^-17 m³(STP)·m/(m²·s·Pa) when the trans membrane pressure difference is 0.10 MPa and the n (PTMOS)/ n (TEOS) ratio is equal to 1.16.

Key words: Organic/Inorganic hybrid separation membrane, Sol-gel technology, Separation factor, Permeability