Bio-derived carbon dot-loaded PVA/CNC films with antioxidant, UV-blocking, and antimicrobial properties for active food packaging.

In this study, polyvinyl alcohol (PVA)/cellulose nanocrystal (CNC)/carbon dot (CD) nanocomposite films were developed to enhance mechanical, water resistance, and UV-blocking properties, specifically for food packaging applications. The CDs were produced through a simple hydrothermal process and uniformly dispersed within the PVA matrix. Incorporating CDs into the PVA/CNC matrix resulted in enhancements in the mechanical strength, thermal stability, and water vapor resistance of the films, along with the introduction of strong antioxidant and antimicrobial properties. These are attributable to the synergistic interactions between CNCs and CDs, which result in the formation of a robust and functional nanocomposite structure. The films demonstrated excellent free radical scavenging capacity as well as strong antioxidant potential, as they effectively inhibited microbial growth in food preservation tests, thereby extending the storage life of perishable foods. The UV-blocking capability of the films was significantly improved, with near-complete UV protection achieved at increased CD concentrations. Furthermore, the effectiveness of the films in preserving food-freshness and minimizing spoilage was confirmed through various packaging trials, making them ideal for active food packaging applications. These findings emphasize the potential of PVA/CNC/CD nanocomposites as sustainable options for food preservation, as they offer multifunctional benefits, including enhanced protection and extended shelf life.