Effects of adding different ethanol amines during membrane preparation on the performance and morphology of nanoporous PES membranes

In this study, different ethanol amines (EAs) were added at various concentrations during the production of membranes. The effects of adding these EAs on the performance and morphology of membranes 200 mu m and 280 mu m thick were investigated. The membranes were obtained via a phase-inversion procedure using polyethersulfone as the base polymer, DMAc as the solvent, and polyvinylpyrrolidone as a pore former. The flux behavior and rejection abilities of these membranes were studied using a crossflow setup. The effects of adding the different ethanol amines during the preparation of membranes on the flux and rejection of these membranes varied significantly. The results showed that membrane performance in the presence of these additives is strongly related to the thickness of the casting film as well as the type of ethanol amine added. Cross-sectional SEM images indicated that these additives have striking effects on the membrane morphology. Diethanol amine is able to increase the fraction of Na2SO4 rejected by the membrane from 70 to near 90 %. The data obtained in this work illustrate that among all of the EAs tested, diethanol amine exerts the greatest effect on membrane performance.