Chitosan and polyvinyl alcohol nanocomposite incorporated with Carbon dots: A proposal for packaging

Packaging materials are essential for food preservation, and multifunctional materials are increasingly being explored for their development. This study proposed the incorporation of Carbon dots (Cdots), obtained from ethylenediamine and citric acid , in polyvinyl alcohol (PVA) and chitosan (CS) films and evaluated the structural, mechanical and optical properties for functional food packaging. The PVA/CS films incorporated with Cdots showed excellent structural, thermal and optical performance. Their high efficiency in blocking UV radiation, especially in the UVC range, reaching more than 80 % blocking for high concentrations of the nanomaterial , stands out. The films maintained adequate transparency and a homogeneous structure, without the formation of agglomerates. Mechanical analyses indicated good tensile strength and improved thermal stability. In addition, cytotoxicity tests demonstrated the safety of the material, proving its viability for contact with food. The integration of Cdots did not compromise the integrity of the polymer matrix , making these films a sustainable alternative for food packaging. The results reinforce the potential of these nanocomposites to extend the shelf life of packaged products, protecting them against photoinduced degradation. • High UV blocking: Film protects against UVA, UVB and especially UVC. • Safe for food contact: Non-toxic and safe material, ideal for food coating. • Sustainable: Based on biodegradable inputs, chitosan, polyvinyl alcohol and Cdot. • Versatile applique: Innovative potential for advanced food packaging and protection. • Bioactive technology: Combines biopolymers and Carbon dot for greater functionality.