Facile in-situ assembly of silver-based MOFs to surface functionalization of TFC membrane: A novel approach toward long-lasting biofouling mitigation

Abstract

Surface functionalization of polyamide thin-film composite (TFC) membranes with advanced nanostructure materials suggests tailored control and objective design of surface characteristics which would generate valuable platforms with improved anti-biofouling/antimicrobial properties, excellent selectivity and permeability. This study, for the first time, presents an innovative and facile deposition procedure for covalent bonding of silver-based metal organic frameworks (Ag-MOFs) on the surface of TFC membrane for forward osmosis (FO) application. The binding of Ag-MOFs on the TFC membrane surface was evaluated by FTIR, XPS, FE-SEM, and EDS analyses. After binding of Ag-MOFs on the surface of TFC membrane, the water permeability decreased slightly from 1.1 to 0.94 L/m2 h bar, while the reverse salt flux reduced from 0.334 to 0.275 L/m2 h compared to the nascent TFC membrane. Confocal microscopy analyses showed that Ag-MOF nanoparticles imparted highly potent antibacterial property to the membrane, resulting in a nearly 100% reduction of live bacteria. Moreover, after 7 months immersing of Ag-MOF membrane in water and depletion of silver, the successful regeneration of Ag-MOFs was achieved which can demonstrate the potential of long-term application of this kind of modified membrane without disassembling the module. The simplicity of the technique, the rapid reaction time and the strong antibacterial property highlight the potential of this technique for the development of novel antimicrobial TFC membranes for water treatment.