Correlation between the pore resistance and water flux of the cellulose acetate membrane

Abstract

In this study, a simple model was proposed to explain the correlation between the EIS results and water flux of a membrane, and a corresponding experiment was designed to confirm it. A series of cellulose acetate membranes with different pore structures were fabricated. The porosity of the membranes was adjusted by adding polyethylene glycol (PEG), which acts as a pore-forming agent, with different molecular weights and contents in the preparation process. Electrochemical impedance spectroscopy (EIS) was utilized to characterize the pore resistance of the membranes. A theoretical equation suggesting an inverse relationship between the pore resistance and water flux was proposed and confirmed by the experimental data. According to this model, EIS can be promisingly used for examining the water flux of separation membranes.