Abstract:
An air-impermeable water vapor transport membrane comprises an active layer on a microporous polymeric substrate. The active layer comprises a polyethylene-oxide containing copolymer and a polar protic solvent in an amount of about 3% to about 100% of copolymer weight in the active layer. Molecules of the protic solvent are bonded to the copolymer. The polar protic solvent reduces temperature-dependent variability in the water- vapor permeability of the membrane.
Abstract:
Water vapor transport membranes for ERV and other water vapor transport applications are provided. The membranes include a substrate and an air impermeable selective layer coated on the substrate, the selective layer including a cellulose derivative and a sulfonated polyaryletherketone. In some embodiments the sulfonated polyaryletherketone is in a cation form and/or the selective layer includes s PEEK and CA in an s PEEK:CA (wt.:wt.) ratio in the range of about 7:3 to 2:3. Methods for making such membranes are provided. The methods include applying a coating solution/dispersion to a substrate and allowing the coating solution/dispersion to dry to form an air impermeable selective layer on the substrate, the coating solution/dispersion including a cellulose derivative and a sulfonated polyarylether ketone. In some embodiments the sulfonated polyaryletherketone is in a cation form and/or the coating solution/dispersion includes s PEEK and CA in an sPEEK:CA (wt.:wt.) ratio in the range of about 7:3 to 2:3.