Engineered biodegradable films from derived carbohydrate with dual UV-shielding and antioxidant activity for...

The environmental crisis triggered by the use of plastic derivatives demands the development of efficient and biodegradable alternatives for packaging materials. The strategy of utilizing agri-waste for developing nanocomposites that can serve as a bioplastic can be valuable. In this study, we report the development of films by incorporating banana pseudo-stem derived carbon quantum dots (CQDs) and nanocellulose (NC) into polyvinyl alcohol/starch/glycerol /carboxymethyl cellulose (CMC) matrix. The CQDs of size 2-3 nm were synthesised via the hydrothermal method, while the NC was extracted through acid hydrolysis exhibiting a crystallinity index of 52%. The films show optimal mechanical and optical properties. Incorporation of CQDs helps achieve a concentration-dependent UV-shielding efficiency up to 97.84% against UV_B and 99.87% against UV_C and prevents photo-oxidative degradation. Additionally, incorporation of CMC results in significant ductility with elongation at break of >101% and antioxidating property with 97.76% radical scavenging rate. We accounted for the real-time packaging efficiency of these films by experimenting on banana via coating and jujube by wrapping as model fruits. Our experiment shows delayed senescence, chlorophyll degradation, and extended shelf-life up to 8 days. Furthermore, the nanocomposite films exhibit nearly 80% biodegradation under natural conditions in soil over 35 days. Overall, the sustainable nanocomposite platform demonstrates potential for packaging application where UV shielding, antioxidant protection, and mechanical flexibility are required.