Graphene oxide (GO) membrane has been synthesized on commercial polysulfone ultrafiltration membranes (Pore size: 17nm) using the drop casting method followed by baking at 90oc for 24 hours. Baking resulted in the reduction of GO and removal of bulk water intercalated in the GO sheets. Deposited GO film showed higher stability under shear stress variation (measured up to 1.7 N/m2). Microstructural defects in graphene oxide membranes lead to a significantly higher permeation of isopropanol (for initially dry GO membrane). Extensive size exclusion (rejection) studies with various dye and dendrimer molecules showed decrease in pore size from 3.3 nm in the “dry” state to 1.3 nm in the “wet” state of GO membranes. FT-IR characterization of GO membrane suggested adsorption of water on the nanochannels of the active layer. Catalytic property of graphene oxide and reduced graphene oxide to activate persulfate was also investigated in this study. Partially reduced graphene oxide improved the catalytic efficiency of the process and enhanced the degradation rates of Trichloro ethylene (probe toxic organic compound).
Reference:
A. Aher, Y. Cai, M. Majumder, D. Bhattacharyya, Synthesis of graphene oxide membranes and their behavior in water and isopropanol, Carbon 116 (2017) 145-153.