Intrinsically antibacterial thin film composite membranes with supramolecularly assembled lysozyme nanofilm as selective layer for molecular separation

Biofouling is a pervasive and crucial issue in membrane separation processes, as it leads to the deterioration in separation efficiency. To address this issue, the antibacterial membrane with high biofouling resistance is in urgent demand, what has been remained challenging. In this work, an intrinsically antibacterial thin film composite (TFC) membranes was prepared using supramolecularly assembled lysozyme (SAL) nanofilm as a selective layer. The nanofilms were achieved by depositing onto a hydrolyzed polyacrylonitrile (h-PAN) support membrane using phase transition and aggregation of lysozyme from its aqueous solution. The prepared membranes showed a high rejection ratio towards vitamin B 12 (95.3%) with a water permeation flux of 48.6 L·m −2 ·h −1 under 0.4 MPa, showing great potential in the molecular separation. Furthermore, the antibacterial efficiencies of the typical membrane toward E. coli and S. aureus reached 93.2% and 92.2%, respectively, indicating that the SAL selective layer can effectively resist bacterial adhesion and reproduction on the membrane surface. This work provides an innovative strategy and insight in fabricating the high-performance antibacterial TFC membranes for aqueous molecular separation via protein supramolecular assembly.