Investigation of UV absorption and antibacterial behavior of zinc oxide containing poly(vinyl alcohol-g-acrylonitrile) (PVA-g-PAN) nanocomposites films

Abstract

The aim of the present study was to investigate the UV absorption properties of PVA-g-PAN/ZnO nanocomposite films prepared by free radical graft copolymerization of acrylonitrile on to PVA and subsequent in situ precipitation of ZnO nanoparticles into the polymer matrix. The nanocomposites were characterized by various analytical methods such as Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, Scanning electron microscopy (SEM) and Atomic force microscopy (AFM) etc. The size of the crystallites and extent of crystallinity were ascertained by X-ray diffraction (XRD) analysis. The SEM with Energy Dispersive X-ray analysis (EDX) showed that the ZnO nanoparticles were uniformly dispersed within the host copolymer matrix. The transmission electron microscopy (TEM) results clearly indicated that the size of zinc oxide nanoparticles varied in the range 10–30 nm. The surface morphology and topography of the PVA-g-PAN/ZnO nanocomposite films were investigated using atomic force microscopy (AFM). The UV-absorption properties of so prepared films were also studied using UV-visible absorption spectroscopy. The results showed that the films were capable of absorbing more than 95 % of incident UV radiations. The antibacterial activities of so prepared nanocomposites were determined against the Gram-negative bacterium Escherichia coli and Pseudomonas aerugenosa, and Gram-positive Micrococcus luteus and Staphylococcus aureus by the disc diffusion test method which showed that the antibacterial activity increased with increasing content of ZnO in the film. The prepared nanocomposites were also studied for swelling behavior.