US Patent 9429366 Energy recovery ventilation sulfonated block copolymer laminate membrane

A core unit for an energy recovery system for exchanging heat and vapor between two independent intake and exhaust airstreams without intermixing thereof, the core unit having a fibrous microporous support substrate and a sulfonated block copolymer having at least one end block A and at least one interior block B wherein each A block contains essentially no sulfonic acid or sulfonate ester functional groups and each B block is a polymer block containing from about 10 to about 100 mol percent sulfonic acid or sulfonate ester functional groups based on the number of monomer units, and wherein the sulfonated block copolymer is laminated on the microporous support substrate.