New Insights in the Ion Beam Sputtering Deposition of ZnO-Fluoropolymer Nanocomposites

Abstract

Abstract:Surface modification treatments able to confer antistain/antibacterial properties to natural or synthetic materials are receiving increasing attention among scientists. Ion beam co-sputtering (IBS) of zinc oxide (ZnO) and poly-tetrafluoroethylene (PTFE) targets allows for the preparation of novel multifunctional coatings composed of antimicrobial ZnO nanoparticles (NPs) finely dispersed in an antistain PTFE polymeric matrix. Remarkably, IBS has been proved to be successful in the controlled deposition of thin nanocoatings as an alternative to wet methods. Moreover, tuning IBS deposition parameters allows for the control of ZnONP loadings, thus modulating the antibacterial/antistain coating's final properties. All the deposited coatings were fully characterized by X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and transmission electron microscopy (TEM) in order to obtain information on the materials' surface composition, with deep insight into the nanocoatings' morphology as a function of the ZnONP loadings. An analysis of high-resolution XP spectra evidenced a high degree of polymer defluorination along with the formation of inorganic fluorides at increasing ZnO volume ratios. Hence, post-deposition treatments for fluorides removal, performed directly in the deposition chamber, were successfully developed and optimized. In this way, a complete stoichiometry for inorganic nanophases was obtained, allowing for the conversion of fluorides into ZnO.

Mixed-ligand zinc-oxoclusters: efficient chemistry for high resolution nanolithography

“…This peak is assigned to fluoride ions, likely bonded to Zn metal (Zn-F) in the thin film after EUV exposure. [55][56][57] The formation of such metal-fluoride bond has been observed in metal complexes after exposure to focused electron beam and was explained by C-F bond cleavage and appearance of F À species. 58 The presence of this peak in low intensity in the unexposed sample is attributed to the chemical changes induced by X-ray photons used for the XPS measurement, as a rise of this peak was observed as a result of prolonged irradiation with X-ray after consecutive measurements on the same spot (Fig.…”

ZnO Nanostructures with Antibacterial Properties Prepared by a Green Electrochemical-Thermal Approach

“…Moreover, ZnO nanomaterials are well-known antimicrobial agents [2], which can be employed in several fields where pathogen spreading should be inhibited [3][4][5]. Besides the many physical [6][7][8] and chemical [9][10][11] methods for the production of such materials, scientific research has recently focused on green and simple electrochemical approaches [12,13]. These synthetic routes have the great advantage of being completely eco-friendly, using mainly aqueous solutions in the absence of reductants or other harmful chemicals [14].…”

Variations of morphology of fluoropolymer thin films versus deposition conditions

“…Deposition is possible onto any substrate or sublayer and co-deposition with any evaporable material to produce nanocomposite thin film without restrictions imposed by wettability and solubility. Plasma polymerization of fluorine containing gas [20,21], ion or magnetron sputtering (MSp) [6,22] and electron beam or laser beam ablation of bulk FP [23][24][25] were used for deposition of FP films. The method of evaporation-activation of PTFE for film deposition in a high vacuum was developed (Electron activated Vacuum Deposition -EVD) [2][3][4].…”