Thin Film Composite Polyamide (TFC-PA) total heat exchange membranes (THEMs) with ultrahigh sensible heat recovery and greatly improved CO2 barrier property

Thin Film Composite Polyamide (TFC-PA) Total Heat Exchange Membranes (THEMs) with ultrahigh sensible heat exchange efficiency, high enthalpy exchange efficiency, high CO 2 gas barrier property were successfully prepared by interfacial polymerization between m-phenylenediamine (MPD) and trimesoyl chloride (TMC). The performances of formed THEMs could be greatly impacted by their surface roughness, thickness, surface hydrophilicity, cross-linking degree and counter-ions retention controlled by the MPD concentration, TMC concentration, reaction time and post treatment procedures. Their H 2 O permeation coefficient could be improved by increasing the surface hydrophilicity and decreasing cross-linking degrees of the formed polyamide layers while their CO 2 barrier property could be improved by retaining more counter ions in PA layers. THEMs with ultrahigh sensible heat exchange efficiency of 95%+, high enthalpy exchange efficiency of 60%–65%, greatly improved CO 2 barrier property and superior mechanical strengths could be obtained for potential applications in ERV systems. • High performance TFC-PA THEMs are developed with low CO 2 crossover. • Excellent sensible heat exchange efficiencies of 99%+ achieved. • IP reaction conditions and post treatment procedures play big roles. • CO 2 barrier property can be modulated by counter ions retained.