CuO and CuO/vermiculite based nanoparticles in antibacterial PVAc nanocomposites

Abstract

Copper oxide (CuO) nanoparticles are used in a wide range of applications due to its specific chemical, surface and microstructural characteristics, excellent physicochemical properties and cost effectiveness. The combination of the CuO with the vermiculite (V) particles allows to the preparation of nanostructured materials with specific properties. CuO nanoparticles were prepared by sonochemical synthetic method followed by a heat treatment (at 350 degrees C for 90 min) with the used of Cu(NO3)(2) and NaOH precursors. Natural V was used for nanocomposite structures preparation (CuO/V). The nanostructured samples were characterized using scanning electron microscopy and X-ray diffraction. The particle size (median diameter, d(50)), xi-potential and specific surface area were analysed. The antibacterial efficiency was evaluated by finding the minimum inhibitory concentration against Staphylococcus aureus and Enterococcus faecalis. The polyvinyl acetate (PVAc) nanocomposite plates were prepared using 0.1, 0.5 and 1 wt% of CuO (respectively CuO/V) nanostructured materials as functional nanofillers and were characterized by X-ray diffraction, scanning electron microscopy and 3D optical light microscope. The positive effect of vermiculite particles on homogeneous distribution in PVAc matrix was shown. The antibacterial activity was evaluated against Staphylococcus aureus and Enterococcus faecalis. Significant antibacterial behavior with long-acting after 24 h against Staphylococcus aureus was evaluated for all PVAc nanocomposites. The results show that already 0.1 wt% of CuO nanofillers (respectively CuO/V) in the PVAc matrix produce an antibacterial surface against Staphylococcus aureus.