Chelation–assisted in situ self-assembly route to prepare the loose PAN–based nanocomposite membrane for dye desalination

In this work, we presented a facile and novel strategy, chelation–assisted in situ self-assembly, to prepare the loose polyacrylonitrile (PAN)–based nanocomposite membrane for dye desalination. Based on the chelate reaction polyethyleneimine (PEI) with metal ions, an Ag + –PEI complex layer was deposited onto the hydrolyzed PAN surface. Then, the chelate complex layer was served as the templates to in-situ synthesize the vitamin E succinate (VES)-functionalized AgCl nanoparticles，which were uniformly distributed on the membrane surface and provided additional transport pathways for water molecules. The prepared nanocomposite membrane achieved the permeability of 106.4, 101.2 and 92.3 L m −2 h −1 MPa −1 , which was 20–50% higher in comparison with that of the pure Ag + –PEI@HPAN membrane, with corresponding rejections of 99.2%, 99.5% and 99.8% to crystal violet, acid fuchsin and congo red solution at the concentration of 0.1 g L −1 . Meanwhile, this membrane possessed a low inorganic salts rejection (6.2%, 9.6% 8.3% and 12.8% for MgCl 2 , NaCl, MgCl 2 and Na 2 SO 4 ) and good stability during the 60 h filtration of dye-salt mixture. We anticipate that this novel route could be applied to prepare the polymer-supported nanocomposite membrane with enhanced separation performance.