Incorporation of kappa-carrageenan as additive in improving characteristics of nanohybrid polysulfone/silver-graphene oxide membranes

Mechanical strength and adaptability are both hallmarks of polymeric polysulfone (PSO membranes. However, the hydrophobicity nature of PSf is the main reason to enhance water permeability and removal capabilities of membranes. Therefore, the characteristics of PSf membranes can be improved by the addition of kappa-carrageenan (k-car), a highly hydrophilic biopolymer. In this study, the incorporation of k-car, a biopolymer composed of anionic polysaccharides that were isolated from specific ocean red-algal species, was investigated. The quantities of k-car ranged from 0.1 to 1.0 wt.% in a composite material including silver graphene oxide (Ag-GO) and PSf. A polymer solution consists of PSf/ k-car /Ag-GO was prepared by dissolving with hydrocarbon solvent, N-methyl 2-pyrrolidone (NMP). The technique of phase inversion was employed in the membrane fabrication process. Membranes were investigated by evaluating their casting viscosity, contact angle, porosity, functional groups, and surface morphologies. The viscosity of the casting solution exhibits an upward trend as the concentration of k-car increases. The observed contact angles for 0.25 wt. % kcar supports the evidence related to the hydrophilic surface characteristic. Results showed that the highest porosity at 78.15% was achieved by the membrane fabricated with the addition of 0.25 wt.% k-car. The incorporation of k-car as a pore-forming agent in the PSf membrane has demonstrated a notable influence on both of its hydrophilicity and morphological properties.