Synergistic effect of oxidized low-dimensional carbon nanomaterials on the properties of polysulfone composite membrane

Abstract

Abstract Using the immersion phase inversion process, polysulfone (PSF), grapheme oxide (GO) and modified carbon nanotubes (MCNTs) were dissolved in 1-methyl-2-pyrrolidone (NMP) to prepare nanocomposite membranes. The GO-MCNTs blended PSF membranes were characterized by several analytical methods, such as morphology analysis, group characteristic peak test, hydrophilic measurement and permeation tests, and the synergistic effect of GO and MCNTs on the membrane performance was investigated. Microscope images depict two-layer structure of the composite membrane, in which, the lower layer is finger like porous layer, and the upper layer is a thinner separation layer. M-CNTs have great influence on formation of the upper separation layer, while the hydrophilic nature of GO results in the formation of the lower supporting layer, which changes from finger shaped hole to honeycomb pore. The change of membrane structure not only improves the surface hydrophilicity, but also promotes the membrane performance. In particular, the composite membrane (m GO:MCNTs = 2:1) exhibits a much smaller contact angle (48.01°), a high permeation flux (33.25 L/m2·h) and superior rejection rate (95.2%). Furthermore, the fine compaction performance of composite membrane also provides great potential application prospects in water treatment.