Enhanced properties of PVDF membranes using green Ag-nanoclay composite nanoarchitectonics

Abstract

Introduction. Polyvinylidene fluoride (PVDF) is widely used in various industries, particularly in water treatment, owing to its effectiveness as an ultrafiltration membrane. Fouling can occur on PVDF membranes during the treatment of aqueous solutions containing natural organic matter in water treatment. Nanofillers can be added to PVDF membranes to improve their durability for more water treatment applications Objectives. This study aimed to enhance the mechanical and anti-biofouling properties of PVDF membranes while maintaining the flux and rejection rates. Methods. A green method was used to synthesize the Ag-Nanoclay nanocomposite for integration into a PVDF polymer membrane. P. argentea extract was employed as a reducing and stabilizing agent for the synthesis of Ag-Nanoclay nanocomposites. The synthesized Ag-Nanoclay nanocomposite was characterized using the X-Ray Diffration (XRD), Fourier-Transform Infrared Spectroscopy (FTIR), and Scanning Electron Microscope (SEM). The phase inversion method was used to prepare the PVDF membranes and 1 wt% and 3 wt% Ag-Nanoclay nanocomposite membranes. The structures, morphologies, performances and mechanical and antibacterial proeprties of the prepared membranes were characterized. Results. The synthesized Ag-Nanoclay consisted of Ag Nanoparticles linked to nanoclay platelets with flavonoids from plant extracts. Incorporating the Ag-Nanoclay nanocomposite into the PVDF membrane resulted in minor increases in the pore size, roughness, and hydrophobicity of the membrane. However, these effects did not significantly affect the flux and rejection rates, which showed little improvement. The 1 wt% loading significantly improved the tensile strength by 67%, whereas it decreased by 50% at 3 wt% loading. Both loading levels demonstrated excellent antibacterial activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), with sterilization rates exceeding 99%. Conclusions. Addition of Ag-Nanoclay to PVDF membranes is a promising strategy for developing advanced membranes with improved mechanical properties and anti-biofouling characteristics.