A new class of nano-antimicrobials was developed by Ion Beam co-Sputtering of ZnO and polytetrafluoro_ ethylene targets. The resulting nanostructured coatings combine the antimicrobial properties of ZnO nanoparticles with the water repellence and anti-stain characters of the dispersing fluoropolymer (CFx). ZnO-CFx nanocomposites were prepared varying ZnO volume fraction (φ) in the CFx matrix by tuning the sputter- ing deposition parameters. Morphological analysis confirmed the presence of homogenously distributed ZnO nanoclusters in the polymer. ZnO loadings ranging in the 0.05-0.15 interval were explored and the nano-composites were characterized by X-ray Photoelectron Spectroscopy (XPS) to investigate their surface chemical composition. XPS spectra evidenced a high degree of polymer defluorina-tion along with the formation of ZnF2 at increasing φ valu-es. Zn speciation was performed on Zn L3M45M45 Auger signal. Coatings bioactivity was assessed against Escheri-chia coli, Staphylococcus aureus, and Kluyveromyces marxianus. At φ ≥ 0.10, ZnO-CFx composites exhibited appreciable antibacterial activity, irrespective of the target organism.
Ion Beam Sputtering deposition and characterization of ZnO-fluoropolymer nano-antimicrobials
SPORTELLI, MARIA CHIARA;NITTI, MARIA ANGELA;VALENTINI, Marco;PICCA, ROSARIA ANNA;BONERBA, ELISABETTA;SABBATINI, Luigia;TANTILLO, Giuseppina;CIOFFI, NICOLA;VALENTINI, Antonio
2014-01-01
Abstract
A new class of nano-antimicrobials was developed by Ion Beam co-Sputtering of ZnO and polytetrafluoro_ ethylene targets. The resulting nanostructured coatings combine the antimicrobial properties of ZnO nanoparticles with the water repellence and anti-stain characters of the dispersing fluoropolymer (CFx). ZnO-CFx nanocomposites were prepared varying ZnO volume fraction (φ) in the CFx matrix by tuning the sputter- ing deposition parameters. Morphological analysis confirmed the presence of homogenously distributed ZnO nanoclusters in the polymer. ZnO loadings ranging in the 0.05-0.15 interval were explored and the nano-composites were characterized by X-ray Photoelectron Spectroscopy (XPS) to investigate their surface chemical composition. XPS spectra evidenced a high degree of polymer defluorina-tion along with the formation of ZnF2 at increasing φ valu-es. Zn speciation was performed on Zn L3M45M45 Auger signal. Coatings bioactivity was assessed against Escheri-chia coli, Staphylococcus aureus, and Kluyveromyces marxianus. At φ ≥ 0.10, ZnO-CFx composites exhibited appreciable antibacterial activity, irrespective of the target organism.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.