Multi-membrane formation in chitosan hydrogel shell by the addition of goethite nanoparticles.

In this study, chitosan (an abundant natural biopolymer) was used as a polysaccharide source to synthesize multi-membrane hydrogel capsules (MHC) using a novel approach. The MHC material was formed in a single step self-assembly approach by an in-situ immobilization of goethite nanoparticles (GNP) during the chitosan-anionic surfactant complex formation reaction. The pivotal role of GNP in the formation of multi-membrane was thoroughly discussed herein. Some important factors effecting the formation and property of MHC were explored. The results of adsorption study (C ≈ 1000 mg/L, 30 °C, and pH ≈ 7.0) demonstrated that MHC (1321 ± 35.6 mg/g) exhibited excellent adsorptive capacity for Congo red dye compared to HC (244 ± 35.6 mg/g) and GNP (91.1 ± 19.6 mg/g). Therefore, the unique characteristics of multi-membranes structures breeds an exciting prospect of application in diverse fields, especially wastewater treatment because of its excellent adsorption capacity for dye contaminants.