Enhancing sustainability: chitosan biopolymers with Ag nanoparticles for eco-friendly applications in food packaging

Converting organic solid waste into biomaterials has recently contributed to reducing economic reliance on fossil fuels. Polymers derived from biomass are gaining appeal for their biofuel, biomedical, and biocomposite uses. Animal cellulose-based biopolymers such as chitosan, have piqued the interest of researchers seeking access to a sustainable biopolymer material. Chitosan films were developed through the crosslinking of chitosan and citric acid using distilled water as a solvent. A hydrogel thus formed was then cast to produce a free-standing film. A comparative analysis of these films was carried out by integrating silver (Ag) nanoparticles as dopants. The study encompasses the entire process including film synthesis, as well as the evaluation of their morphological and thermal properties. Various techniques were employed for the characterization of the films, which includes UV-Vis spectroscopy, X-ray diffraction, SEM, EDAX, AFM, TGA, and DSC. The results shed light on how the inclusion of Ag nanoparticles influences the characteristics of chitosan. Chitosan films were evaluated for migration potential towards dry foods, yielding satisfactory results in terms of their suitability for food packaging materials. The suspension of chitosan films in water was accompanied by a determination of their physical and chemical properties, revealing that water quality remained at satisfactory levels. These films were identified to meet stringent food grade standards and were observed to contribute to the reduction of biomass through their integration into the natural recycling process.