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/m 2 ·h and 96.4 %, while the flux and rejection of the original PES membrane was only 702.04 L/m 2 ·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.