Modification of Asymmetric α-Al_2O_3 Microfiltration Membranes by Repeating Dip-Coating Procedure

This paper deals with the modificaiton of asymmetric α-Al 2O 3 microfiltration membranes by repeating the dip-coating procedure.On the basis of the effective control of the modified membrane thickness by adjusting such processing parameters as solid volume of particles and viscosity of suspensions,dipping time and withdrawal speed,the experimental results show that the repeat procedure can be used not only to restore the membrane surface,but also to further modify the membrane structure by lessening the pore size and narrowing the pore size distribution.