Growth of TiO₂/Cu films by HiPIMS for accelerated bacterial loss of viability

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• 作者：Sami Rtimi ; Oualid Baghriche ; Cesar Pulgarin ; Jean-Claude Lavanchy ; John Kiwi
• 关键词：HIPIMS sputtering ; Nano-composite layers ; E. coli viability ; Coating thickness ; Metal savings ; ICP-MS
• 刊名：Surface and Coatings Technology
• 出版年：2013
• 出版时间：15 October, 2013
• 年：2013
• 卷：232
• 期：Complete
• 页码：804-813
• 全文大小：1086 K

文摘

This study shows the first complete report on ultrathin TiO₂/Cu nano-particulate films sputtered by highly ionized pulsed plasma magnetron sputtering (HIPIMS) leading to fast bacterial loss of viability. The Cu- and the TiO₂/Cu sputtered films induced complete Escherichia coli inactivation in the dark, which was not observed in the case of TiO₂. When Cu was present, the bacterial inactivation was accelerated under low intensity solar simulated light and this has implications for a potential for a practical technology. The design, preparation, testing and surface characterization of these innovative films are described in this study. The HIPIMS sputtered composite films present an appreciable savings in metals compared to films obtained by conventional sputtering methods. HIPIMS sputtering induces a strong interaction with the rugous polyester 3-D structure due to the higher fraction of the Cu-ions (M⁺) attained in the magnetron chamber. The Cu-leaching during the bacterial inactivation was monitored by ion-coupled plasma mass spectrometry (ICP-MS) and found to be in the ppb range. The amounts found were below the cytotoxicity level allowed by the standards related to human health. The immiscibility of Cu and TiO₂ in the TiO₂/Cu films is shown by High Angular Dark Field (HAADF) microscopy. A mechanism for the photo-induced interfacial charge transfer (IFCT) between TiO₂ and Cu is suggested.