Preparation and Characterization of PVA/Nanocellulose/Ag Nanocomposite Films for Antimicrobial Food Packaging

Abstract

Antimicrobial packaging is an area of emerging interest and it is rapidly expanding with the application of nanotechnology. The present study describes the development of bionanocmoposites by casting/evaporation of polyvinyl alcohol (PVA), nanocellulose (NC), and Ag nanoparticles. The study was carried out to investigate the effect of NC and Ag NPs on the morphology, mechanical properties, thermal properties, water vapour transmission rate (WVTR), moisture retention capability (MRC), antibacterial activity and cytotoxicity evaluation of PVA nanocomposite films. The films were found to be homogenous, depicting the uniform dispersion of NPs.The tensile strength of PVA was improved from (5.52±0.27 MPa) to (12.32±0.61 MPa) when filled with 8 wt% NC. Furthermore, the maximum tensile strength obtained at 12 wt% NC with 0.1 g Ag NPs was (83.66±4.18 MPa). Due to the presence of NC and Ag NPs, thermal degradation of the nanocomposite films occurred at higher temperature and a significant reduction was observed for WVTR measurements. No significant differences between the films were observed which indicates similar moisture retention capability (MRC) of the films. The PVA/NC/Ag nanocomposite films exhibited strong antibacterial activity against both Staphylococcus aureus (MRSA) and Escherichia coli (DH5-alpha). The maximum inhibition zone at 0.5 g Ag NPs with 12 wt% NC against Gram- negative bacteria (DH5-alpha) was 14 mm. While, the maximum inhibition zone at 0.3 g Ag NPs for 16 wt% NC was 13.6 mm against Gram- positive bacteria (MRSA). Moreover, the results showed that nanocomposites films have no cytotoxicity effect on Hep G2. The cell viability was more than 70%. Based on the obtained mechanical as well as antibacterial potential of the developed nanocomposite films, it can be envisaged to use these films for packaging applications.