Evaluation of TiO2 and Ag-TiO2, CuO-TiO2 composite films for self-disinfection activity

The removal or killing of microorganisms on surfaces is of concern in the health care setting, food preparation areas and general work environment. The use of TiO2 photosterilisation has been proposed as an alternative to chemical disinfection of surfaces as a means to reduce the need for increasingly concentrated and aggressive chemicals necessary to kill disinfectant-resistant organisms. The objective of this research was to evaluate the ability of photocatalytic oxidation to reduce bacterial and viral contaminants on surfaces coated with TiOa and Ag-TiC^, TiO2-Ag, Cu-TiC^, TiO2-Cu. There are no British Standards that cover evaluation of such surfaces. A method for evaluation of photocatalytic surfaces was therefore developed from BS EN 13697:2001 and used to evaluate the activities of a variety of catalytic surfaces coated with TiO2, Ag and Cu and multi-layers of Ag-TiO2,TiO2-Ag, Cu-TiO2,TiO2-Cu. The antimicrobial activities were found to be dependent on the nature of the coating. Highest killing activities were obtained with Ag and Cu alone but combinations of Ag or Cu with TiO2were more active than TiO2 alone and also retained some self- cleaning activity. The results showed that the developed method was adaptable for determination of the antimicrobial activity of coatings with a wide range of activities producing 100% killing of Escherichia coll in times from 3 min up to 4 h. The results showed that it was possible to produce self cleaning self disinfecting surfaces and that surfaces with TiO2 on top, although having reduced activity compared to Ag or Cu, were durable and may have applications in the prevention of transmission of infections on surfaces in a wide range of applications.EThOS - Electronic Theses Online ServiceGBUnited Kingdo