Characterization of cellulose-derived carbon dots/polyvinyl alcohol films and their application in blueberry preservation

A cellulose-derived CDs/PVA composite film was prepared as a multifunctional food packaging material. CDs were synthesized by a one-pot water heating method, with a size distribution ranging from 1.05 to 6.65 nm, and were incorporated into the PVA matrix at concentrations between 0.2 % and 0.8 % to create the nano-composite film. SEM images confirmed the compatibility and potential hydrogen bonding between the low-concentration CDs (<0.4 wt%) and the matrix. This interaction improves the mechanical strength of the composite films. Optical analysis of CDs/PVA films showing good UV shielding effect. Thermal characteristics showed that moderate CDs doping (0.4 wt%) reduced the T g of PVA to 64.1 °C and increased the carbonization rate to 8.49 % at 500 °C. The film with 0.6 wt% CDs demonstrated exceptional DPPH/ABTS scavenging rates of 61.56 % and 97.07 %, along with antibacterial efficiencies of 85 % against E. coli and 87 % against S. aureus . In the blueberry storage test, this film inhibited 10 % spoilage and 10 % weight loss within 8 days. Safety assessment test confirms that the total migration of the film is <10 mg/dm 2 . The nanocomposite films we prepared provide a sustainable bio-based solution for food packaging.