Preparation of high-permeance ceramic microfiltration membranes using a pore-sealing method

A pore-sealing method for preparation of high-permeance alumina microfiltration (MF) membranes free of any intermediate layers is presented. It involves sequential coating of a polyvinyl butyral (PVB) layer and an alumina membrane precursor on the surface of the macroporous alumina support. An alumina MF membrane with no intermediate layers can be obtained on the support after pyrolysis of the PVB interlayer. The interlayer-free membrane prepared by this method has an average pore diameter of 0.26 μm and a water permeance of 1468 ± 81 L m^-2 h^-1 bar^-1 which is prominently higher than that of the ceramic membranes prepared with other techniques. The conspicuous increase of water permeance is speculated mainly due to the filtration resistance decrease of the interlayer-free ceramic membrane.