Process for increasing the selectivity of anisotropic gas separation membranes

摘要

Anisotropic gas separation membranes are treated to alter the microporosity of their thin, dense layer or composite coating-the layer or coating which provides selectivity in separations employing such membranes. The treatment increases the selectivity of a membrane with minimal decrease in its flux. The process comprises applying a polar activator to the membrane followed by exposing the membrane to microwave frequency radiation for a period of time sufficient to compact the thin layer of the membrane. The polar activator may be incorporated in the membrane during fabrication or applied as an after-treatment.