A STUDY ON THE PREPARATION OF NON-SUPPORTED GAMMA-ALUMINA MEMBRANES BY SOL-GEL METHOD

A series of nonsupported gamma-alumina membranes were prepared by usin g sol-gel method. The influences of preparation parameters including a cid/alkoxide ratio, water/alkoxide ratio, alcohol/alkoxide ratio, hydr olysis temperature, and calcination condition were investigated. From the experimental results, it indicated that the acid/alkoxide ratio an d calcination temperature play important roles on controlling the micr ostructural properties of the membrane. The gamma-alumina membranes ca n be obtained under various hydrolysis temperatures even below 80 degr ees C, and the minimum pore size occurred at about 60 degrees C of hyd rolysis. With the same amounts of acid, both the particle size of the sol and pore size of the membrane obtained by the PMU route were sligh tly smaller than that by the DCS route. The relationship among prepara tion conditions, properties of boehmite sols and mircostructure of mem branes were also discussed.