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:
A heat and humidity exchanger has example application in exchanging heat and water vapour between fresh air entering a building and air being vented from the building. The heat and humidity exchanger has a self-supporting core formed from layered sheets (710, 720) of a moisture-permeable material. Plenums (750) are arranged to direct fluid streams into and out of the core. The plenums (750) may be on opposing sides of the core to permit counterflow exchange of heat and water vapour. The plenums (750) are attached to the core along opposite edges of the sheets (710, 720).
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.
Abstract:
A water vapour transport membrane comprises a nanofibrous layer disposed on a macroporous support layer, the nanofibrous layer coated with a water permeable polymer. A method for making a water vapour transport membrane comprises forming a nanofibrous layer on a macroporous support layer and applying a water permeable polymer to the nanofibrous layer. The water permeable polymer can be applied for so that the nanofibrous layer is substantially or partially filled with the water permeable polymer, or so that the coating forms a substantially continuous layer on one surface of the nanofibrous layer. In some embodiments of the method, the nanofibrous layer is formed by electro-spinning at least one polymer on at least one side of the porous support layer. In some embodiments, the support layer is formable and the method further comprises forming a three-dimensional structure from the water vapour transport membrane, for example, by compression molding, pleating or corrugating.