Robust and highly hydrophilic ultrafiltration membrane with multi-branched cellulose nanocrystals for permeability-selectivity anti-trade-off property

To overcome challenges associated with the “trade-off” effect and membrane fouling, the high-performance ultrafiltration membranes were prepared by blended multi-branched nanocellulose (Multi CNC) into polyethersulfone (PES) matrix using non-solvent induced phase separation (NIPS) technology. The as-prepared composite ultrafiltration membranes have high hydrophilicity, thicker skin layer and lower negative charge due to the abundant polar groups of carboxyl (COOH) in Multi CNC. As the results, the water flux and Bovine serum albumin (BSA) rejection of the composite membranes with 1 wt% Multi CNC reached to 961.65 L/m2·h and 96.4 %, while the flux and rejection of the original PES membrane was only 702.04 L/m2·h and 86.2 % respectively, thus the “trade-off” was effectively improved by loading of Multi CNC. Moreover, the flux recovery ratio (FRR) of MCP1 (FRR = 74.08 %) was 2.1 times as much as the original PES membranes (FRR = 34.81 %) in the water-BSA-water filtration process, verified that the introduction of Multi CNC could effectively improve the anti-fouling ability of composite membranes. Such hydrophilic composite ultrafiltration membranes with robust mechanical performance could be developed for pharmaceutical and biotechnological industries.