PVC/copper oxide composites and their effect on bacterial adherence

Abstract

In this work, PVC/CuO and PVC/Cu2O composites were prepared by melt-blending method. The results of scanning electron microscopy (SEM) - X ray energy dispersive spectroscopy (EDS) Cu-mapping showed that the composites are a hybrid of the polymer and the copper oxide particles, and these particles were distributed uniformly in the polymer matrix. The adherence of Escherichia coli ATCC 25922 on the surface of composite materials was assessed through the inventory of adhered viable cells and SEM analysis. In PVC/copper oxide composite, the number of adhered bacterial cells was reduced by almost 2 units log10 with regard to those adhere to the pure PVC polymer. SEM images of composite materials showed a significant decrease in bacterial adherence when compared to the pure polymer. It was also found through transmission electron microscopy (TEM) images to that E. coli incubated in the presence of cuprous oxide (Cu2O) and cupric oxide (CuO) microparticles go through structural and morphological changes at the membrane level. Bacterial cells incubated in the presence of Cu2O were bacillary with blunt ends, and their size was reduced by 30% when compared to those incubated in the absence of copper oxides. The results obtained indicate that the PVC/copper oxide composites inhibit the adhesion of E. coli to their surface. © 2012 Sociedad Chilena de Química.