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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.


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.


Huizing R.,University of British Columbia | Huizing R.,dPoint Technologies | Merida W.,University of British Columbia | Ko F.,University of British Columbia
Journal of Membrane Science | Year: 2014

Membranes with high water vapour permeance and selectivity find many end uses including protective clothing, dehydration, and humidification. One application for water vapour transport membranes is in energy recovery ventilators (ERVs) for buildings. These devices improve building energy efficiency by transporting heat and moisture between incoming and outgoing air streams in building ventilation systems, effectively 'recycling' the energy used to condition the indoor air. Membranes for these devices must have high vapour permeance, and selectivity for water vapour over other gases and contaminants that may be present in the exhaust indoor air. Due to the high rates of water vapour transport required in these gas to gas devices, boundary layer and internal resistances within the membrane contribute significantly to performance. Commercially available membranes suffer from high water vapour transport resistance in the microporous substrate support layer. In this study we report the fabrication of novel impregnated electrospun nanofibrous membranes (IENM) for water vapour transport applications. Electrospun nanofibre layers are impregnated with a polyether-polyurethane solution and cured to create continuous thin impregnated fibre loaded film layers which are bound to a non-woven support layer. These membranes have high water vapour permeance and selectivity while eliminating the requirement for a microporous support layer which has high vapour transport resistance. Here we report initial studies on how controllable factors in the membrane fabrication (namely fibre loading and impregnated solution polymer solids concentration) affect structural and permeation properties of IENMs created. Membranes with adequate permeance and selectivity are demonstrated and direction for optimization is identified. We find that the nanofibre loading has a significant impact on water vapour permeability as the membrane thickness decreases. Future work will study how modifications to the geometric and structural properties of the fibres affect the membrane performance. © 2014 Elsevier B.V.


Patent
dPoint Technologies | Date: 2012-12-19

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).


A membrane cartridge is manufactured by repeatedly folding and joining two strips of membrane to form a cross-pleated cartridge with a stack of openings or fluid passageways configured in an alternating cross-flow arrangement. The cartridge can be modified for other flow configurations including co-flow and counter-flow arrangements. Methods for manufacturing such cross-pleated membrane cartridges, as well as apparatus used in the manufacturing process are described. Cross-pleated membrane cartridges comprising water-permeable membranes can be used in a variety of applications, including in heat and water vapor exchangers. In particular they can be incorporated into energy recovery ventilators (ERVs) for exchanging heat and water vapor between air streams being directed into and out of buildings.


Patent
dPoint Technologies | Date: 2010-05-17

Coated membranes comprise a porous desiccant-loaded polymer substrate that is coated on one surface with a thin layer of water permeable polymer. Such membranes are particularly suitable for use in enthalpy exchangers and other applications involving exchange of moisture and optionally heat between gas streams with little or no mixing of the gas streams through the membrane. Such membranes have favorable heat and humidity transfer properties, have suitable mechanical properties, are resistant to the crossover of gases when the membranes are either wet or dry, and are generally low cost.


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.


Patent
dPoint Technologies | Date: 2016-06-16

A heat and humidity exchanger has example application in exchanging heat and water vapor 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 of a moisture-permeable material. Plenums are arranged to direct fluid streams into and out of the core. The plenums may be on opposing sides of the core to permit counterflow exchange of heat and water vapor.


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.


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