A self-supported gel filter membrane for dye removal with high anti-fouling and water flux performance

Traditional polymer filtration membranes are easily polluted in operation. An interpenetrating polymer network (IPN) gel was designed as a self-supported filter membrane. This IPN gel was structured by a Ca2+ crosslinked alginate network and a covalently crosslinked poly(acrylamide) network. Polyethylene glycol-polyhedral oligomeric silsesquioxane (PEG-POSS) was hybridised into the gel to optimise performance. Our research demonstrated that the uniform dispersion of PEG-POSS in the matrix improved membrane performance comprehensively due to its nanoscale and amphipathicity. The membranes showed well mechanical properties and sewage treatment capacity. Under the operation pressure 2 bar, the water flux of membranes could keep 11.7 L m(-2)h(-1) in long-term use. When dealing with the high concentration (500 mg L-1) of Methylene blue and Congo red solution, the rejection of dye could reach 93% and 95% respectively. In anti-fouling experiments with 8000 mg L-1 protein emulsion as the fouling source, the membranes keep over 80% initial flux after 10 times of water-emulsion cycle.