Graphene oxide-Chitosan thin film composite loose nanofiltration membranes synthesis with interfacial polymerization for textile dye recovery.

Abstract

The present invention presents a method for synthesis a new loose nanofiltration membranes nanocomposite through interfacial polymerization between 1,3-cyclohexane bis (methylamine) (CHMA) and Chloride cyclohexane1,3,5-tricarbonyle (HTC) on a PES for ultrafiltration. The incorporation of as graphene oxide (GO) / chitosan (Gs) additive was investigated. The process involves several steps: first, preparing of support by dissolving a polymer in solvent. In the second step, the support membrane immersed in bath which contains CHMA following the dispersion, graphene oxide (GO) and chitosan (Gs) and after the membrane was immerged in organic phase. The interfacial polymerization between the two monomers results in a nanofiltration membrane being formed on the surface of the support membrane. The resulting composite nanofiltration membrane features a loose surface structure, with composite embedded within a polyamide nano-layer during polymerization. This design enhances the surface hydrophilicity and creates a sandwich-like structure where polyamide grows perpendicular to the nanoparticles. The upper and lower polyamide layers protect the nanoparticles from damage under high pressure, while also optimizing the membrane's structural stability, permeability, and filtration performance. The optimized LNF-4 showed excellent water permeability (20.54 LMH), low salt rejection (Na2SO4> MgSO4>NaCl) and good dye rejection (96%). Therefore, the proposed new strategy for preparing this nextgeneration LNF membranes can contribute towards the textile wastewater treatment.