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Cu and CuO nanoparticles immobilized by silica thin films as antibacterial materials and photocatalysts

Akhavan, O ; Sharif University of Technology | 2010

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  1. Type of Document: Article
  2. DOI: 10.1016/j.surfcoat.2010.06.036
  3. Publisher: 2010
  4. Abstract:
  5. CuO nanoparticles with average diameter of about 20. nm were accumulated on surface of sol-gel silica thin films heat treated at 300 °C in air. Heat treatment of the CuO nanoparticles at 600 °C in a reducing environment resulted in effective reduction of the nanoparticles and penetration of them into the film. While the thin films heat treated at 300 °C exhibited a strong antibacterial activity against Escherichia coli bacteria, the reducing process decreased their antibacterial activity. However, by definition of normalized antibacterial activity (antibacterial activity/surface concentration of coppers) it was found that Cu nanoparticles were more toxic to the bacteria than the CuO nanoparticles (by a factor of ~. 2.1). Thus, the lower antibacterial activity of the reduced thin films was assigned to diffusion of the initially accumulated copper-based nanoparticles into the film. The CuO nanoparticles also exhibited a slight photocatalytic activity for inactivation of the bacteria (~. 22% improvement in their antibacterial activity). Instead, the normalized antibacterial activity of the Cu nanoparticles covered by a thin oxide layer highly increased (~. 63% improvement) in the photocatalytic process. A mechanism was also proposed to describe the better antibacterial activity of the Cu than CuO nanoparticles in dark and under light irradiation
  6. Keywords:
  7. Photocatalysts ; Anti-bacterial activity ; Antibacterial materials ; Antibacterial properties ; Average diameter ; Concentration of ; Copper oxide nanoparticles ; Copper-based ; Cu nanoparticles ; CuO nanoparticles ; Escherichia coli bacteria ; Light irradiations ; Photocatalytic activities ; Photocatalytic process ; Reducing environment ; Reducing process ; Silica thin films ; SiO2 thin films ; Sol-gel silica ; Thin oxide layers ; Bacteriology ; Copper oxides ; Escherichia coli ; Gels ; Nanoparticles ; Silica ; Sol-gel process ; Sol-gels ; Sols ; Thin films ; Vapor deposition ; Copper
  8. Source: Surface and Coatings Technology ; Volume 205, Issue 1 , September , 2010 , Pages 219-223 ; 02578972 (ISSN)
  9. URL: http://www.sciencedirect.com/science/article/pii/S0257897210004676