In Situ Synthesis of Silver Nanoparticles within Hydrogel-Conjugated Membrane for Enhanced Antibacterial Properties

Biofouling negatively impacts water treatment performance of membranes by reducing water permeability, increasing energy consumption, and shortening the lifetime of the membranes. In this study, we integrated the bactericidal property of silver nanoparticles (AgNPs) with hydrophilicity of hydrogels to modify membranes that not only reduce adhesion, but also deactivate the adhered bacteria. Two approaches for AgNP synthesis were adopted—in situ synthesis and encapsulation in single step, and immobilization in multistep. Formation of AgNPs was confirmed by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD) studies. Compared to the pristine membrane, AgNP/hydrogel-modified membranes displayed no adverse effect in water flux under gravitational flow condition. The AgNP/hydrogel-modified membranes also exhibited better antibacterial properties (inhibition of adhesion and growth of Escherichia coli) as demonstrated by the bacterial growth, inhibition zone...