Mills, Andrew and Lee, Soo-Keun and Sheridan, Martin (2005) Development of a novel UV indicator and dosimeter film. Analyst, 130 (7). pp. 1046-1051. ISSN 0003-2654Full text not available in this repository. (Request a copy from the Strathclyde author)
A novel UV indicator is described, comprising nanocrystalline particles of titania dispersed in a film of a polymer, hydroxyl ethyl cellulose (HEC), containing: a mild reducing agent, triethanolamine (TEOA) and a redox indicator, methylene blue (MB). The UV indicator film is blue-coloured in the absence of UV light and loses colour upon exposure to UV light, attaining within a few min a steady-state degree of bleaching that can provide a measure of the irradiance of the incident light. The original blue colour of the film returns once the source of UV light is removed. The spectral characteristics of a typical UV indicator film, and its components, are discussed and the UV-absorbing action of the titania particles highlighted. From the measured %bleaching undergone by a typical UV indicator as a function of light irradiance the indicator appears fully bleached, within 7 min, by a UV irradiance of 3 mW cm-2 or greater. The mechanism by which the UV indicator works is described. The reversible nature of the UV indicator is removed by covering a typical UV indicator with a thin, largely oxygen impermeable, polymer film, such as the regenerated cellulose found in Sellotape. The product is a UV dosimeter, the response of which is related to the intensity and duration of the incident UV light, as well as the amount of titania in the film. A typical UV dosimeter film is fully bleached by 250 mJ cm-2 of UV light. The possible use of these novel indicators to measure UV exposure levels, irradiance and dose, is discussed.
|Keywords:||UV indicator, dosimeter film, Chemistry, Biochemistry, Spectroscopy, Environmental Chemistry, Analytical Chemistry, Electrochemistry|
|Subjects:||Science > Chemistry|
|Department:||Faculty of Science > Pure and Applied Chemistry
|Depositing user:||Mr Derek Boyle|
|Date Deposited:||09 Mar 2006|
|Last modified:||06 Jan 2017 03:40|