Effect of sodium alginate/phosphate-stabilized amorphous calcium carbonate nanoparticles on chitosan membranes

Biodegradable chitosan (CS) films can meet the demand for sustainable development. However, the performance of pure CS membrane still exists a particular gap compared with the traditional film. Inorganic nanomaterials with the controllable release are added to improve its physical and chemical properties. Herein, a series of CS/phosphate-stabilized amorphous calcium carbonate (CS/ACCP) and CS/sodium alginate/ACCP (CS/Alginate/ACCP) composite films were prepared by the flow method. The effects of ACCP and Alginate/ACCP nanoparticles on the physical and chemical properties of the composite membrane were investigated. The results showed that the composite nanoparticles could significantly improve CS film's compactness, hydrophobicity, and mechanical properties and enhance its ultraviolet (UV) blocking ability, water resistance, and water vapor blocking ability. When the number of nanoparticles was 8%, the mechanical properties of the CS composite membrane reached optimum value, and the comprehensive performance was better. In addition, the controlled-release properties of CS composite membranes were also studied, and the antioxidant, antibacterial, biocompatibility, and fresh-keeping effects of the composite membranes were explored. The results indicated that the CS composite membranes had not only excellent bacteriostatic (72%) properties (Escherichia coli) but also presented well fruit preservation (15 days) properties (sugar orange). In particular, the controlled release range of CS composite membrane at 12 h was between 30% and 90%, which provided a theoretical basis for its use as an edible membrane. Therefore, based on ACCP and Alginate/ACCP nanoparticles, CS composite membranes with more excellent application value in the biological field were prepared through further optimization design.