Composite membrane for a membrane distillation system

摘要

A composite membrane separates a distilland and a distillate, such as salt water and fresh water. The composite membrane comprises a thin lyophobic microporous layer or membrane and a thin lyophilic layer or membrane on both sides of the lyophobic membrane or on the distillate side. Evaporation and condensation takes place within the micropores of the lyophobic membrane. The lyophilic layer on the distilland side prevents intrusion of distilland into the pores of the lyophobic layer. The lyophilic layer on the distillate side changes the surface curvature of the liquid/vapor interface in a manner which enhances the distillation rate through the membrane.