Long-lasting antibacterial behavior of a novel mixed matrix water purification membrane

Membrane fouling by microbial and organic components is considered as the "Achilles heel" of membrane processes as it not only reduces the membrane performance but also leads to membrane biodegradation. In this work, a novel high flux, antibacterial and antifouling ultrafiltration membrane was fabricated by blending the silver nanoparticles (AgNPs)-halloysite nanotubes (HNTs)-reduced graphene oxide (rGO) nanocomposite (AgNPs-HNTs-rGO) into a polyethersulfone (PES) membrane matrix. HNTs were applied to expand the interlayer space between neighboring rGO sheets and eliminate the leaching on AgNPs. The hybrid membranes had higher hydrophilicity, surface smoothness and higher water permeation flux when compared with the pure PES membrane. Both dynamic and static BSA adsorption tests revealed improved antifouling behavior of the hybrid membrane. In addition, the incorporated AgNPs were evenly attached onto the rGO support with an average size of 10 nm, which ensured its good antibacterial performance: the hybrid membrane had an ideal bacteriostasis rate against Escherichia coli (E. coli) even after six months of storage