Physicochemical, mechanical, optical, microstructural and antimicrobial properties of novel kefiran-carboxymethyl cellulose biocomposite films as influenced by copper oxide nanoparticles (CuONPs)

The aim of this study was to produce novel nanobiocomposites based on kefiran-carboxymethyl cellulose and investigate effects of adding 1, 1.5 and 2% copper oxide nanoparticles (CuONPs) on their properties. An increase in CuONPs concentration increased contact angle and ultimate tensile strength and decreased water vapor permeability and elongation at break. Increased nanoparticle concentration generally improved color parameters and percentage of light transmission. Hydrogen bonds between polymer matrix and CuONPs were observed using Fourier transform infrared spectroscopy. Dynamic mechanical thermal analysis showed an increase in storage modulus and glass transition temperature of the nanobiocomposites. CuONPs were observed to be uniformly distributed across polymer matrix using scanning electron microscopy. X-ray diffraction analysis indicated that CuONPs maintained their crystalline structure on polymer matrix. Moreover, the nanobiocomposites exhibited inhibitory effects against Staphylococcus aureus and Escherichia coli bacteria. Briefly, results demonstrated that with respect to their higher opacity (to suppress oxidation and discoloration) and antimicrobial properties, the produced nanobiocomposites may have a potential for use in food packaging.