title: Doped Thin-Film Sensors via a Sol-Gel Process for High-Acidity Determination.
abstract: An optical sensor has been developed for high-acidity ([H(+)] = 1-11 M) measurements. The sensor is made of thin films of silica sol-gels doped with an acid indicator. Acid- and base-catalyzed methods to make the sol-gel films have been studied, and the properties of the sol-gel sensors prepared by these methods are discussed. The acid-catalyzed method was found to give more robust films and has been optimized to prepare thin films which are mechanically and chemically stable for a period of at least 3 months. The performance of the sensors resulted in a relative standard deviation of less than 2.5%. The response time is short (1 s), and a small hysteresis was observed during reproducibility measurements with 2-10 M HCl solutions.
authors.affiliation: Department of Chemistry, The University of Tennessee, Knoxville, Tennessee 37996-1600.
authors.forename: L R
authors.initials: LR
authors.lastname: Allain
authors.forename: K
authors.initials: K
authors.lastname: Sorasaenee
authors.forename: Z
authors.initials: Z
authors.lastname: Xue