title: A fiber optic, ultraviolet light-emitting diode-based, two wavelength fluorometer for monitoring reactive adsorption.
abstract: Construction and use of an ultraviolet light-emitting diode-based fluorometer for measuring photoluminescence (PL) from powder samples with a fiber optic probe is described. Fluorescence at two wavelengths is detected by miniature photomultiplier tubes, each equipped with a different band pass filter, whose outputs are analyzed by a microprocessor. Photoluminescent metal oxides and hydroxides, and other semiconducting nanoparticles, often undergo changes in their emission spectra upon exposure to reactive gases, and the ratio of the PL intensities at two wavelengths is diagnostic of adsorption. Use of this instrument for reactive gas sensing and gas filtration applications is illustrated by measuring changes in the PL ratio for zirconium hydroxide and zinc oxide particles upon exposure to air containing low concentrations of sulfur dioxide.
authors.affiliation: Department of Chemistry, University of Massachusetts Lowell, Lowell, Massachusetts 01854, USA.
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Granz
authors.affiliation: Leidos, Inc., P.O. Box 68, Gunpowder, Maryland 21010, USA.
authors.forename: Bryan J
authors.initials: BJ
authors.lastname: Schindler
authors.affiliation: U.S. Army Edgewood Chemical and Biological Center, Aberdeen Proving Ground, Maryland 21010, USA.
authors.forename: Gregory W
authors.initials: GW
authors.lastname: Peterson
authors.affiliation: Department of Chemistry, University of Massachusetts Lowell, Lowell, Massachusetts 01854, USA.
authors.forename: James E
authors.initials: JE
authors.lastname: Whitten