Polyvinyl alcohol-carboxymethyl cellulose bionanocomposite films containing ZnO nanoparticles: Structure and characterization

Bionanocomposites, due to their unique properties, have attracted significant interest in recent years, particularly for applications in industries, such as food packaging. In this study, we focused on developing and characterizing biodegradable polyvinyl alcohol (PVA)/carboxymethyl cellulose (CMC)/glycerol blend bionanocomposites containing zinc oxide (ZnO) nanoparticles. The films were fabricated using the solution-casting method, and the effects of varying ZnO loadings (ranging from 0 to 7 phr) on the bionanocomposites' structural, thermal, mechanical, barrier properties, and surface wettability were investigated using various techniques. Successful integration of ZnO into the polymer matrix was confirmed, with a decrease in the degree of crystallinity observed as ZnO content increased. SEM micrographs revealed a porous morphology due to the chain scission effect of ZnO. TGA indicated a slight reduction in thermal stability, while DMA showed a decrease in the glass transition temperature and storage modulus with ZnO addition. Higher ZnO loadings resulted in increased WVP, attributed to enhanced chain mobility and the hydrophilic nature of ZnO NPs. Tensile testing demonstrated improved elongation at break but decreased tensile strength. The antibacterial assay revealed significant enhancement in antimicrobial activity with increasing ZnO content. The shelf-life study of strawberries indicated the potential of these bionanocomposites for food packaging applications.

Highlights

• Biodegradable PVA/CMC/glycerol blend bionanocomposites with ZnO NPs were developed.
• Characterized structural, thermal, mechanical, barrier, and antimicrobial properties.
• ZnO NPs reduced the crystallinity and thermal stability of bionanocomposites.
• Bionanocomposites showed better elongation but lower tensile strength.
• ZnO NPs added antibacterial properties, extending strawberry shelf-life.