title: Extractive scintillating polymer sensors for trace-level detection of uranium in contaminated ground water.
abstract: This contribution describes the synthesis of robust extractive scintillating resin and its use in a flow-cell detector for the direct detection of uranium in environmental waters. The base poly[(4-methyl styrene)-co-(4-vinylbenzyl chloride)-co-(divinylbenzene)-co-(2-(1-napthyl)-4-vinyl-5-phenyloxazole)] resin contains covalently bound fluorophores. Uranium-binding functionality was added to the resin by an Arbuzov reaction followed by hydrolysis via strong acid or trimethylsilyl bromide (TMSBr)-mediated methanolysis. The resin was characterized by Fourier-transform infrared spectroscopy and spectrofluorometry. Fluorophore degradation was observed in the resin hydrolyzed by strong acid, while the resin hydrolyzed by TMSBr-mediated methanolysis maintained luminosity and showed hydrogen bonding-induced Stokes' shift of ∼100 nm. The flow cell detection efficiency for uranium of the TMSBr-mediated methanolysis resin was evaluated at pH 4, 5 and 6 in DI water containing 500 Bq L-1uranium-233 and demonstrated flow cell detection efficiencies of 23%, 16% and 7%. Experiments with pH 4, synthetic groundwater with 50 Bq L-1uranium-233 exhibited a flow cell detection efficiency of 17%. The groundwater measurements show that the resins can concentrate the uranyl cation from waters with high concentrations of competitor ions at near-neutral pH. Findings from this research will lay the groundwork for development of materials for real-time environmental sensing of alpha- and beta-emitting radionuclides.
authors.affiliation: Department of Chemical and Biomolecular Engineering, Clemson University, 127 Earle Hall, Clemson, SC 29634, USA.
authors.forename: Christine E
authors.initials: CE
authors.lastname: Duval
authors.affiliation: Department of Environmental Engineering and Earth Sciences, Clemson University, 342 Computer Court, Anderson, SC 29625, USA.
authors.forename: Timothy A
authors.initials: TA
authors.lastname: DeVol
authors.affiliation: Department of Chemical and Biomolecular Engineering, Clemson University, 127 Earle Hall, Clemson, SC 29634, USA. Electronic address: shusson@clemson.edu.
authors.forename: Scott M
authors.initials: SM
authors.lastname: Husson
keywords: Chelating resin; Organic scintillator; Uranium detection; Water quality monitoring