One-step fabrication and analysis of an asymmetric cellulose acetate membrane for heat and moisture recovery

A one-step approach is employed to prepare an asymmetric cellulose acetate (CA) membrane that is used for total heat recovery (heat and moisture recovery). The process only involves a cheap raw material of CA, an environmental friendly solvent acetic acid and an additive deionized water. A porous support layer and a dense skin layer are formed simultaneously during the solvent and coagulant medium exchange. Investigations found that the approach is successful in making membranes for heat and moisture recovery. The new membranes have high moisture permeability. Moreover, the permeation of other unwanted gases like CO2 is effectively prohibited. Analysis found that the optimum solution compositions for casting membranes are: acetic acid to deionized water ratio 70:30. The approach provides an environmental friendly yet economical solution for preparing membranes for heat and moisture recovery.