Core tip: The composite membrane uses microporous membrane or ultrafiltration membrane as the supporting layer, and the thickness of the membrane is only 0.1~0.25 μ M thick homogeneous membrane is used as separation membrane composed of barrier layer.

Composite membrane uses microporous membrane or ultrafiltration membrane as the supporting layer, and its surface is covered with a thickness of only 0.1~0.25 μ M thick homogeneous membrane is used as separation membrane composed of barrier layer. This will greatly increase the permeability of the material. What are the preparation methods of composite membranes?

The preparation methods are divided into four categories:

(1) The lamination method is to prepare a very thin dense homogeneous membrane, and then laminate it on the microporous support membrane;

(2) Dip coating method: the polymer solution is dipped on the microporous membrane and then dried, or the active monomer or prepolymer solution can be dipped on the microporous membrane and cured by heat or radiation;

(3) The plasma vapor deposition method uses the plasma glow to make the surface of the microporous support film produce a dense homogeneous film;

(4) Interfacial polymerization method: on the surface of microporous support membrane, the active monomer is used for interfacial polymerization.