Preparation of poly(vinyl chloride)/copper nanocomposite films with reduced bacterial adhesion

Abstract

Films of poly(vinyl chloride)/copper (Cu) nanocomposites exhibiting reduced bacterial adhesion were prepared by film-casting method. Cu nanoparticles (NPs) synthesized using polyol method and stabilized with poly( N-vinyl-2-pyrrolidone) (PVP) at different Cu/PVP molar ratio were previously characterized using transmission electron microscopy (TEM), X-ray diffraction (XRD) and ultraviolet–visible spectroscopy. Zero valent Cu NPs with average diameter of 4 nm were obtained. The nanocomposite films with low and high Cu content were prepared with Cu NPs obtained from Cu/PVP molar ratio of 7.2, 45 and 270. XRD patterns of PVC/Cu nanocomposite films did not show peaks associated at copper oxide and other impurities. Scanning electron microscopy (SEM) and X-ray energy dispersive spectroscopy Cu-mapping revealed a homogenous distribution of Cu NPs agglomerates in nanocomposite films prepared with Cu NPs obtained from Cu/PVP ratio of 7.2 and high Cu content, while TEM images of this nanocomposite film with low Cu content showed well-dispersed and distributed Cu NPs in PVC matrix. The films prepared with Cu NPs obtained from Cu/PVP ratio of 270 showed a vertical phase separation, where PVP was segregated to the free surface. SEM images revealed a reduced Escherichia coli adhesion to PVC/Cu nanocomposite films after 4 days of incubation with respect to plasticized PVC.