Modification of PVDF membranes by incorporation Fe₃O₄@Xanthan gum to improve anti-fouling, anti-bacterial, and separation performance

This study describes the synthesis and characterization of Fe3O4@Xanthan gum (XG) nanocomposite with increased hydrophilicity and anti-bacterial properties, and its application in the fabrication of nanocomposite-based mixed matrix polyvinylidene fluoride (PVDF) membrane using the phase inversion method. The Fe3O4@XG was synthesized by the in-situ co-precipitation technique. The characteristics of the membranes were investigated in terms of morphology, dye and BSA removal performance, anti-fouling behavior, and anti-bacterial properties. The incorporation of very small amounts of Fe3O4@XG NPs, i.e. 0.1 and 0.2 wt%, improved 5% and 17% water flux of the PVDF nanocomposite membranes due to the increased membrane hydrophilicity. Most particular, 0.5 wt% Fe3O4@XG/PVDF membrane was revealed a maximum water flux of 167.2 L·m-2·h-1 at 3 bar, which was 52% greater performance than the pure PVDF membrane. Reactive Black 5 and Reactive Red 120 dye rejections were enhanced from 77.6% to 84.8% and 66.6-73.8% respectively in 0.2 wt% Fe3O4@XG/PVDF membrane compared to the pure PVDF membrane. The best anti-fouling performance was also exhibited by 0.2 wt% Fe3O4@XG/PVDF membrane with an increased FRR value (66.5%) compared with the pure one. In addition, the results of the anti-bacterial test with E. coli showed that the anti-bacterial capabilities of the Fe3O4@XG/PVDF membranes were remarkable and have resisted contamination.