FABRICATION OF MULTILAYER TUBULAR NANOPOROUS CERAMIC MEMBRANES VIA GEL-CASTING FOLLOWED BY DIP-COATING

Multilayer tubular nanoporous ceramic membranes were successfully prepared via gel-casting followed by dip-coating. Tubular alumina porous support systems were manufactured by gel-casting method with pore size in the range of 100-600 nm. Interlayer and top-layer were fabricated with appropriate thickness, morphology and pore size distribution via dip-coating of submicron and nano alumina slurries respectively. The effects of the several parameters such as: solid content, dipping time, vacuum pressure, heating rate and number of coated layers on the structural properties of the prepared nanoporous ceramic membranes were studied to get an appropriate pore size and defect-free surface and then the optimum condition was presented. The morphology and surface quality of nanoporous ceramic membranes were investigated by optical microscopy (OM) and thickness of fabricated interlayer and top-layer were examined with scanning electron microscopy (SEM). Mercury porosimeter measurements were performed to determine the open porosity, pore size and pore size distribution (PSD) of nanoporous ceramic membranes