Preparation and characterization of bio-nanocomposite films incorporating copper nanoparticles

Antimicrobial carboxymethyl cellulose (CMC)/pectin (P)/copper (Cu) nanocomposite films were prepared by a facile approach. Copper nanoparticles (CuNPs) were prepared initially using Psidium guajava leaf extract by a green synthesis method. The CuNPs were incorporated into the CMC/P films at various concentrations. The films were characterized using a universal testing machine (mechanical strength); 2–10% CuNPs addition did not significantly increase the tensile strength, but the oxygen transmission rate (OTR) and water vapor transmission rate were changed significantly by the addition of 2% and 4% of CuNPs, respectively. The scanning electron microscopy data showed tetragonal CuNPs formation in the surface morphology of the nanocomposite films. The antimicrobial properties tests showed larger clear inhibition zones for the nanocomposite films compared to the pure CMC/P films against three different bacterial cultures. The results revealed that the CMC/P/Cu nanocomposite films could be used as an active packaging system in food applications.