Amphiphilic Poly(acrylonitrile-co-acrylic acid)/Silver Nanocomposite Additives for the Preparation of Antibiofouling Membranes with Improved Properties

This work focuses the preparation of polymer-silver nanocomposite (Ag-Nc) dense free standing films and nonwoven fabric supported porous ultrafiltration membranes with improved membrane performance and long-term antibiofouling properties. New polyacrylo-nitrle-based Ag-Ncs, poly(acrylonitrle-co-acrylic acid)silver (PAN-co-PAA-Ag) containing 35 wt% of PAA and 0.35-0.65 wt% of Ag-nanoparticles (Nps) were synthesized and used as additives for the fabrication of PAN-based (PAN/PAN-co-PAA-Ag) Ag-Nc porous membranes and dense-free standing films. The Ag-Nps were homogeneously dispersed into the PAN-co-PAA random copolymer matrix. The prepared membranes (PAN/PAN-co-PAA-Ag) showed combination of properties such as excellent antimicrobial activity towards both Gram Negative and Gram Positive bacteria (prevent biofilm formation), improved protein antifouling properties, and enhanced water flux when compared to neat PAN-based membrane. The antimicrobial properties, hydrophilicity, and the water flux of various membranes follow the following order for the membranes PAN < PAN/PAN-co-PAA < PAN/PAN-co-PAA-Ag. Extraneous addition of small amount of polyethylene glycol (PEG) during preparation of additive i.e. [PEG + PAN-co-PAA]-Ag further improved the protein antifouling properties of the PAN-based membranes (PAN/[PEG+PAN-co-PAA-Ag]). The dispersed Ag-Nps were stable on the surface of phase inverted membranes for long period of time and PAN/PAN-co-PAA-Ag membranes are therefore suitable for long-term water treatment under bacterial environment. POLYM. COMPOS., 32:1851-1861, 2011. (C) 2011 Society of Plastics Engineers