The composite membrane material may comprise any combination of materials, such as metal oxide coated on a ceramic membrane or a microporous polysulfone film coated with an aromatic polyamide film having a PE film or roll film to be used for non-woven microporous film was enhanced to support the pressure resistance, while the hollow fiber membrane is not required.
Preparation divided into four categories: (1) lamination method, first prepared are very thin dense membrane, and then laminated to the microporous support film; (2) dip coating method, the polymer solution was dip-coated on the microporous film and then drying is made to be the reactive monomer or prepolymer solution was dip coated in the microporous film, heat or radiation curable; (3) plasma vapor deposition, plasma glow microporous support surface of the membrane to produce a dense homogeneous film; (4) interfacial polymerization, a microporous support membrane on the surface, with an active monomer interfacial polymerization.