On January 25, the research group led by Prof. Wang Yan of the School of Chemistry and Chemical Engineering and the research group led by Prof. Li Song of the School of Energy and Power Engineering jointly published a paper entitled “Polyamide-based membranes with structural homogeneity for ultrafast molecular sieving” on Nature Communications. The first authors are Dr. Shen Liang, graduate student Cheng Ruihuan and doctoral student Yi Ming of Huazhong University of Science and Technology.

Thin-film composite membranes formed by conventional interfacial polymerization generally suffer from the depth heterogeneity of the polyamide layer, i.e., nonuniformly distributed free volume pores, leading to the inefficient permselectivity. Here, the research group demonstrates a facile and versatile approach to tune the nanoscale homogeneity of polyamide-based thin-film composite membranes via inorganic salt-mediated interfacial polymerization process. Molecular dynamics simulations and various characterization techniques elucidate in detail the underlying molecular mechanism by which the salt addition confines and regulates the diffusion of amine monomers to the water-oil interface and thus tunes the nanoscale homogeneity of the polyamide layer. The resulting thin-film composite membranes with thin, smooth, dense, and structurally homogeneous polyamide layers demonstrate a permeance increment of ~20–435% and/or solute rejection enhancement of ~10–170% as well as improved antifouling property for efficient reverse/forward osmosis and nanofiltration separations. This work sheds light on the tunability of the polyamide layer homogeneity via salt-regulated interfacial polymerization process.

Link to this paper: https://www.nature.com/articles/s41467-022-28183-1