Highly bioactive silver and silver/titania composite films grown by chemical vapour deposition

Abstract

This paper describes how photocatalytically active films of TiO 2, grown by thermal CVD, may be functionally and structurally modified by deposition of nanostructured silver via a novel flame assisted CVD process. The resulting composite films are shown to be highly durable, highly photocatalytically active and are also shown to possess strong antibacterial behaviour.The deposition control, arising from the described approach, offers the potential to control the film nanostructure, which is proposed to be crucial in determining the photo and bio-activity of the combined film structure, and the transparency of the composite films.Furthermore, we show that the resultant films also exhibit "self regeneration" capability, in that they both kill bacteria present on the film surface and then photodegrade the residues. Such a dual action significantly reducing the problems of surface deactivation due to build up of contamination.These properties are especially significant when combined with the well-known durability of CVD deposited thin films, offering new opportunities for enhanced application in areas where bio-active surface functionality is sought.

A review on the application of inorganic nano-structured materials in the modification of textiles: Focus on anti-microbial properties

“…Three famous crystalline structures for TiO 2 have been known as anatase (tetragonal, a = 0.3785 nm, c = 0.9514 nm, band gap = 3.2 eV which is equivalent to a wavelength of 388 nm), rutile (tetragonal, a = 0.4593 nm, c = 0.2959 nm, band gap = 3.02 eV) and brookite (orthorhombic, a = 0.9182 nm, b = 0.5456 nm, c = 0.5143 nm, band gap = 2.96 eV) [74,[76][77][78][79][80].…”

Titanium Oxide Antibacterial Surfaces in Biomedical Devices

“…Since the demonstration of its antimicrobial activity, UV-activated TiO 2 has been used in suspension, in liquids, or immobilized on surfaces for the destruction of Gram-negative and Gram-positive bacteria, including endospores, fungi, algae, protozoa, viruses as well as for the inactivation of microbial toxins and prions (45,72,(118)(119)(120)(121)(122)(123)(124)(125)(126)(127). Ions such as Cu 2+ and Ag + in combination with TiO 2 were reported to enhance its antimicrobial activity (72).…”

Photocatalytic Activity of Reactively Sputtered Titania Coatings Deposited Using a Full Face Erosion Magnetron

“…Depending on the property of the film layer a specific photocatalytic activity test, dry or wet is selected. For instance, whilst stearic acid (dry method) can produce non-continuous contacts between the stearic acid and the surface of the film [29][30][31][32][33], using methyl orange [34][35][36] or methylene blue [37] dyes can result in the production of continuous contact between the surface of the film and the solution. The latter method suits a photocatalytic test in which an electron exchange is involved and that was the major testing technique used for this study.…”