k-Carrageenan - A versatile biopolymer for the preparation of a hydrophilic PVDF composite membrane

摘要

Biopolymer k-carrageenan (kCg) was used as a hydrophilic polymer additive to develop a novel polyvinylidene fluoride (PVDF) composite membrane. The effect of kCg content (0.5, 1.0, 2.0 wt . %) on membrane morphology and porosity, membrane hydrophilicity and surface charge, viscosity of casting solutions was investigated. The membrane performance attributes were evaluated by the water permeability, and rejection of methyl orange dye. We observed in the results that, with the addition of kCg, an asymmetric membrane structure was formed owing to the accelerated demixing process that resulted from the increase in hydrophilicity of the composite PVDF/kCg. The smooth surface, increased hydrophilicity, and negatively charged surface of the composite PVDF/kCg membrane resulted in strong resistance in adhering to a dye; therefore, the resulting composite membranes had a higher dye rejection and water permeability. Hence, the developed composite PVDF/kCg membrane could be considered as a potential membrane material for separation applications.