Graphene Oxide (GO)-Blended Polysulfone (PSf) Ultrafiltration Membranes for Lead Ion Rejection

作者：Harish Ravishankar, Jens Christy, Veeriah Jegatheesan · 发表于：Membranes · 年份：2018 · DOI：10.3390/membranes8030077 · 被引用次数：79 · 研究领域：Membrane Separation Technologies、Graphene and Nanomaterials Applications、Graphene research and applications

Graphene oxide (GO) has been widely reported and used for treatment of heavy metals from different waste streams. Although their use as additives for membranes has greatly enhanced membrane properties, there is still a bottleneck in obtaining membranes with high heavy-metal rejection efficiencies while maintaining high flux, mechanical strength, and porosity. In the present study, different compositions of GO (0⁻1 wt %)-blended membranes were prepared using 1-methyl-2-pyrrolidone (NMP) as solvent and water with 5% ethanol as non-solvent, and studied for the rejection of the chosen model heavy-metal lead. The prepared membranes were characterized for hydrophilicity, membrane porosity, flux, permeability, pore-size, mechanical strength, and membrane morphology. From the results, it was inferred that membranes having maximum GO in their blend (1 wt %) showed better hydrophilicity (water contact angle 34.2°), porosity (82.2%), permeability (52.1 L/m² h bar), and pure water flux (163.71 L/m² h) at 3-bar pressure as opposed to other compositions. The pore sizes of the membranes ranged between 18 to 24 nm. Tensile strength tests showed the role of GO as a positive reinforcement on the mechanical properties of membranes through Young's modulus (188.13 ± 15.36 MPa) for the membrane having 0.25 wt % GO composition. Environmental Scanning Electron Microscopy (ESEM) images displayed the dense top layer supported by a porous, finger-like structure, obtained from instantaneous de-mixing fa...