Enhanced Barrier and Antimicrobial Properties of Maleic Anhydride-Modified Polyvinyl Alcohol Nanocomposite Films Embedded with Multiwall Carbon Nanotubes Decorated with Nano ZnO for Food Packaging Applications

This study investigates the modification of polyvinyl alcohol (PVA) with maleic anhydride (MAH) to produce modified PVA (PVA-MAH), and the development of PVA-MAH nanocomposite films embedded with multiwall carbon nanotubes decorated with nano zinc oxide (MWCNTs-NZnO) using a solution blending approach. FTIR analysis confirmed the formation of a robust three-dimensional network between MAH and PVA, involving ester, coordination, and hydrogen bonds, which DSC analysis further corroborated through an observed increase in glass transition temperature. Modification with MAH and the integration of MWCNTs-NZnO improved moisture resistance and swelling behavior, with MAH enhancing crosslink density to reduce moisture uptake, while optimal MWCNTs-NZnO concentrations further mitigated water absorption. Excessive MWCNTs-NZnO content, however, led to aggregation, compromising structural integrity and diminishing nanocomposite performance. The PVA-MAH/MWCNTs-NZnO films displayed optimal elongation at break, contact angle, and gas barrier properties at 0.3% MWCNTs-NZnO, achieving significant improvements in water vapor and oxygen barrier properties-394% and 282%, respectively, over pure PVA-while maintaining high transparency. The study also identified four primary mechanisms contributing to enhanced barrier properties, with SEM revealing increased agglomeration at 0.9% MWCNTs-NZnO. Antibacterial testing demonstrated strong inhibition of Escherichia coli and Staphylococcus aureus, while antifungal testing revealed high effectiveness against Penicillium fumiculosum and Aspergillus niger. Meat packaging tests further indicated that PVA-MAH/MWCNTs-NZnO nanocomposites effectively extended food preservation and shelf life. Thus, this high-performance nanocomposite film shows strong potential for application in food packaging, offering improved barrier, antimicrobial, and antifungal properties.