Optical characteristics and bacterial-resistance ability of PVA/ZnO nanocomposites

Abstract

Poly(vinyl alcohol) (PVA) thin films with different amounts of zinc oxide (ZnO) nanoparticles (NPs) (0.001, 0.002, 0.003, 0.004 and 0.005 ​g) were prepared using the casting method. The structural characteristics of the PVA polymer, ZnONPs and the mixture of polymer and ZnO NPs with a particle size of 80 ​nm have been studied using X-ray diffraction, Scanning Electron Microscopy and Fourier Transform Infrared spectroscopy. The optical characteristics of PVA/ZnO nanocomposites were studied in the wavelength range of 200–700 ​nm. According to experimental research, adding more ZnONPs to nanocomposites improves the PVA polymer's absorbance, absorption coefficient, extinction coefficient, refractive index and real and imaginary dielectric constants. As the amount of ZnONPs increases, the transmittance and energy gap of the PVA polymer decrease. Research on the antibacterial activity of these nanocomposites was conducted using Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Klebsiella quasipneumoniae subsp. Similipneumoniae as pathogen microorganisms. According to the findings, the antibacterial activity of NPs is greatly influenced by their chemical make-up and form. Moreover, increasing the amount of ZnO in the composites causes an increase in antibacterial activity.