Design of TiOxNy for Coating Technology

Abstract

Extended AbstractTitanium dioxide is extensively used for medical and industrial applications including drug delivery, tissue engineering, white pigment, antimicrobial agent, biological active coatings, etc. Based on the literature data, the photocatalytic properties of the TiO 2 are strongly dependent on nature and concentration of dopant agents, on morphology and especially size, crystallographic form and so on. TiO 2 is also extensively used for developing functional coatings because of the synergism of the surface properties and photocatalytic properties -which induce antimicrobial activity. Even if TiO 2 is increasingly used in many applications only limited data are available relating to the modification of TiO 2 in order to design it for coating. When titanium dioxide is designed as coating material additional properties are necessary: adhesion on the surface, flexibility, etc. These new characteristics can be easily obtained by modifying the TiO 2 by partial substitution of oxygen with nitrogen. Based on the literature data, the content of nitrogen can be between 4 and 70% with minimal alteration of the desired properties (including biocompatibility). In this context, we proposed three TiO x N y materials and characterized from the point of view of composition, size and shape and photocatalytic activity. Further works will be necessary them in order to identify the proper deposition conditions onto various surfaces and characterize the coating characteristics (thickness and homogeneity); stability, photocatalytic activity. Based on the preliminary data, the photocatalytic activity is exhibited also in the visible light which is essential in maintaining a clean surface able to selfclean and function during the daily light [1, 2]. These systems will be possible to use in various applications such as water purification but also can be designed to be applied on glasses to assure the self-cleaning, anti-reflexive surfaces, antifogging, etc. [3,4]. These materials are also suitable for medical applications and especially for stent technology [5][6][7]. For medical applications, the cellular response is essential. For stents, it is recommended a low adhesion to cells while, for medical implants, especially bone implants a good adhesion is required. For the environmental applications the non-toxic activity is recommended but the most important characteristic is related to the photocatalytic activity especial in visible light.