A separation module comprising a porous asymmetric membrane, comprising a poly(phenylene ether) copolymer comprising repeat units derived from 2,6-dimethylphenol and repeat units derived from 2-methyl-6-phenylphenol, and having an intrinsic viscosity of 0.7 to 1.5 deciliters per gram, measured in chloroform at 25° C. and a weight average molecular weight of 100,000 to 500,000 daltons, measured by gel permeation chromatography against polystyrene standards;
- and an amphiphilic block copolymer;
- wherein the porous asymmetric membrane is in a flat sheet, hollow fiber, capillary, or tubular configuration.