Preparation and characterization of sol-gel derived 4%La2O3-Al2O3 ceramic membrane on clay-based supports

In this work, gamma-Al2O3 membrane layer (4 wt % La2O3 + 96 % Al2O3) was coated on the clay based porous support by using the sol-gel coating. The coating solution was prepared by using boehmite (AlOOH), La-nitrate (La-2(NO3)(3).6H(2)O), PVA, distilled water and HNO3. The thickness of the gamma-Al2O3 membrane layer was between 5-7 mum. Two unprocessed clay samples which were supplied from Kutahya and Balikesir regions.. were used to produce supports for the membranes. Porosities of the supports were varied from 25 to 40% depending on sintering temperatures. Mean pore diameter of the supports were between 0.01-1mum. The mean pore diameter of 4wt%La2O3-Al2O3 membrane layer was around 11 nm and total pore area was 113 m(2)/g at 1000degreesC for 1 hour.