Effects of Nonsolvent-Additive in Membrane Casting Solution on Gas Permeability

摘要

Use of oxygene-enriching or nitrogne-enriching memebrane has received much attention as a way of metting the increasing demand for energy-efficient operation or inert atmosphere operation. Since the homogeneous membrane can only give low gas permeability, asymmetric membrane has been studied to improve perselectivity for gas separation. In making asymmetric membranes by the dry/wet phase inversion process, usually adding an organic nonsolvent for the polymer into the membrane casting oslution is very improtnat to obtian the optional membrane structure and improves performance of the resulting membranes. By adding propionic acid(PA) into the membrance casting solution containing polysulfone (PSf) and N-methyl-2-pyrrolidine (NMP) Kesting et al prepared PSf asymmetric membrane with high permeation flux.