Nanocomposites based on Polypropylene and Copper Nanoparticles: Preparation, Surface Activation by Plasma and Antibacterial Activity

Abstract

This work reports the preparation of polypropylene nanocomposites with copper nanopar­ticles (PP/nCu) by melt blending, as well as their surface treatment by argon plasma in order to increase the antibacterial activity of compounds obtained. The nanocomposite surface analysis, corroborated by means of Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM), demonstrates that argon plasma treatment modifies the surface of the compound, increasing the exposure of nanoparticles and, therefore, roughness of the mate­rial. Argon plasma favors polymeric chain scission at the surface, removing polymer chains and forming active sites, which in contact with the environment incorporates oxygen and nitrogen species, increasing the material´s polarity, as demonstrated by X-ray photoelec­tron spectroscopy (XPS) analysis and contact angle measurements. The exposure of surface nanoparticles and polarity shifts of eroded nanocomposites produced a significant increase in antimicrobial activity against pathogenic bacteria Staphylococcus aureus and Pseudomo­nas aeruginosa. Plasma treatment use for surface modification of nanocomposites is an ef­fective tool to obtain antimicrobial nanomaterials with a high value-added.