Highly improved permeation property of thin-film-composite polyamide membrane for water desalination

Thin-film-composite (TFC) polyamide membranes with flux-enhancement were prepared by the interfacial polymerization of m-phenylenediamine with trimesoyl chloride on porous polysulfone support. The addition of 1,3-propanesultone (PS) in the organic phase is used to influence the interfacial polymerization process and the morphology of polyamide layer to improve water flux. FTIR, ¹H NMR and UV spectra were performed to investigate the effect of PS on interfacial polymerization process. In order to study the forming mechanism of TFC membrane, the resulting TFC membranes were characterized by SEM, AFM, ATR-FTIR, XPS, as well as static contact angle. In comparison with conventional polyamide membrane, the TFC membranes fabricated with PS as the additive exhibit much more improved water flux without NaCl rejection decreasing. Notably, the optimal TFC membrane with 0.04% (wt/v) PS as the additive in organic phase shows the best performance with a NaCl rejection of 99.39% and a water flux of 48.57 L m⁻² h⁻¹ at 1.55 MPa, which has increased 41% compared to the value of the conventional TFC membrane.