Biodegradable poly(vinyl alcohol) films reinforced with zinc oxide-functionalized carbon nanosheets derived from <i>Punica granatum</i> peels for sustainable food packaging

The escalating environmental impact of non-biodegradable plastic packaging has accelerated the development of sustainable and active food packaging materials with enhanced mechanical and antimicrobial performance. Pomegranate peel-derived nanosheets (P-CNs) were produced in an eco-friendly way and further enhanced with zinc oxide (ZnO@P-CNs). Although ZnO nanoparticles are commonly employed in food packaging due to their antibacterial qualities, difficulties such as nanoparticle aggregation and low reinforcing efficiency can limit their overall effectiveness. In this study, ZnO@P-CNs was developed to combine the mechanical reinforcement capability of CNs with the antimicrobial activity of ZnO, while improving nanoparticle dispersion and interfacial compatibility within the PVA matrix in comparison to conventional ZnO fillers. The incorporation of ZnO@P-CNs significantly enhanced film performance, resulting in a 203% increase in flexural strength; the <i>T</i>_20% and <i>T</i>_50% values (degradation temperature) were also increased by 17.1 and 57.07 °C, respectively. In addition, the nanocomposite films exhibited strong antimicrobial activity, achieving great inhibition against Gram-negative bacteria, along with effective antifungal activity against common food spoilage fungi <i>Aspergillus niger</i> and <i>Candida albicans</i>.