Fabrication of cellulose acetate/Fe₃O₄@GO-APTS-poly(AMPS-co-MA) mixed matrix membrane and its evaluation on anionic dyes removal

In this work, a novel mixed matrix membrane (MMM) was developed based on cellulose acetate (CA), graphene oxide (GO) nanosheets, and Fe₃O₄ magnetic nanoparticles. In the first step, a nanocomposite was prepared by grafting 2-acrylamide-2-methyl propanesulfonic acid-maleic anhydride copolymer [poly(MA-co-AMPS)] on the functionalized GO surface (GO-APTS) and decorating with Fe₃O₄ nanoparticles. Then, the prepared nanocomposite [Fe₃O₄@GO-APTS-poly(AMPS-co-MA)] was blended with CA and membranes with different compositions were prepared via phase inversion procedure. Hydrophilicity, thermal properties, morphology, and surface roughness of the MMMs were studied by water contact angle, TGA, FE-SEM, and AFM techniques, respectively. Filtration properties and dye removal performance of the prepared membranes were evaluated. The highest rejection achieved by the membrane containing 0.2 wt% nanocomposite for all of the tested anionic dyes (Acid Blue 7, Reactive Red 120, and Direct Red 23), reaching up to 100% at pH = 9. This observation was interesting, that only 0.2 wt% of the additive had a huge impact on the rejection efficiency compared to the pure CA membrane for about 20%.