Comparison of The Effectiveness of Sunscreen Lotions Using A TiO2-based UVA/UVB Dosimeter

TCE

The Chemical Educator

ISSN: 1430-4171 (electronic version)

Table of Contents

Abstract Volume 3 Issue 2 (1998), S1430-4171(98)02187-7

Comparison of The Effectiveness of Sunscreen Lotions Using A TiO₂-based UVA/UVB Dosimeter

Minhua Wang,¹ Jiansheng Huang,¹ Yuzhuo Li,¹* and William F. Barnard²

¹Department of Chemistry, Clarkson University, Potsdam, NY 13699-5810
²REAL, US-EPA, Research Triangle Park, NC 20771

Published online: 2 April 1998

Abstract. This paper describes a simple method for the evaluation of the effectiveness of a sunscreen product. It illustrates the basic principle of semiconductor (such as TiO₂) band gap, band-gap excitation, conduction-band electron trapping, and its application as an effective dosimeter in the UVB and UVA regions. The color change of the dosimeter, prepared from TiO₂ sol, can be quantitatively determined with a UV/Vis spectrometer or qualitatively by visual inspection. The experiment can be used as a freshman-chemistry laboratory exercise or performed as a classroom demonstration for high school students or nonchemistry-major college students.

Key Words: Laboratories and Demonstrations; sunscreen lotions; UVA; UVB; UVC; radiations; photochemistry; dosimeters; TiO₂; particles; anatase; rutile

(*) Corresponding author. (E-mail: yuzhuoli@craft.clarkson.edu)

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