A novel interfacial polymerization approach towards synthesis of graphene oxide-incorporated thin film nanocomposite membrane with improved surface properties

The conventional interfacial polymerization (IP) technique that requires a rubber roller in removing amine aqueous solution is likely to cause uneven distribution of nanomaterials on microporous substrate during thin film nanocomposite (TFN) membrane fabrication. A novel IP technique was developed in this work to pre-coat the substrate with graphene oxide (GO) nanosheets followed by vacuum filtration of amine aqueous solution through the substrate before initiating polyamide cross-linking process. This novel technique was also employed to fabricate a composite membrane that contained no nanomaterials. The results showed that the GO-incorporated TFN membrane exhibited 71.7% and 129.4% higher pure water flux compared to the composite membranes without GO incorporation that were synthesized using conventional and filtration IP technique, respectively. The water enhancement of the TFN membrane could be attributed to the existence of hydrophilic GO that was distributed evenly throughout the substrate surface coupled with the formation of porous selective layer that reduced water transport resistance. Besides exhibiting promising rejection against divalent ions, the newly developed TFN membrane also showed significantly lower water flux deterioration in filtrating bovine serum albumin and Reactive Black 5 solution. The enhanced membrane antifouling resistance was mainly due to the improved membrane surface properties that minimize deposition and adsorption of foulants on the TFN membrane surface.