Second interfacial polymerization decorating defects of TFC NF membrane formed by 1D nanochannels for improving separation performance

Abstract

Generating nanovoids/nanochannels in the polyamide rejection layer is an effective method to enhance the separation performance of thin-film composite (TFC) membranes. However, the excessive nanovoids/nanochannels formed in the rejection layer will cause defects and reduce the selectivity. Here we report a secondary interfacial polymerization (SIP) method to decorate the defects caused by one-dimensional (1D) nanochannels, which were generated by etching 1D copper hydroxide nanorods (CuNRs). The obtained SIP-1D NF membrane had a pure water permeability of 8.2 L·m−2·h−1 bar−1, while the divalent salts rejection was 92.0 ± 2.6% of Na2SO4, 91.3 ± 0.3% of MgCl2, and 91.8 ± 0.2% of MgSO4. Our work provides experimental basis for 1D nanochannels regulate the structures and properties of NF membrane.