Ioana Sizemore, Ph.D. (Advisor); Steven Higgins, Ph.D. (Committee Member); David Dolson, Ph.D. (Committee Member); Lynn Hartzler, Ph.D. (Committee Member); Sushil Kanel, Ph.D. (Committee Member)
Doctor of Philosophy (PhD)
The proliferation of silver nanoparticles (AgNPs) in consumer products and industrial applications has generated many environmental concerns since the chemistry of silver changes at the nanoscale and the very properties that make them desirable – their unique reactivity – may pose environmental risks. This dissertation addresses these concerns from three different angles. First, freshwater crayfish is demonstrated as a potential benthic indicator of Ag pollution since Ag accumulation depends on the form of Ag. The uptake and distribution of Ag (from AgNPs or Ag+) in tissue samples were measured by inductively coupled plasma optical emission spectroscopy (ICP-OES). The hepatopancreas (1.5-17.4 µg of Ag g-1 of tissue) was identified as the best tissue-indicator of AgNP pollution while the gills (4.5-22.0 µg g-1) and hepatopancreas (2.5-16.7 µg g-1) complementarily monitored the presence of Ag+. Next, label-free and labeled-enhanced Raman imaging is proposed as a method to characterize AgNPs adsorption behavior and distribution to minerals. The results of this study demonstrate that label-free Raman can detect direct chemical interactions (Ag-O stretching at 241 cm-1) while Label-enhanced Raman can reveal AgNPs distribution, when no molecular interactions are spectroscopically detected, through a SERS-probe. Lastly, an educational laboratory module developed to introduce undergraduate and graduate STEMM students to AgNPs, ICP-OES, and US EPA endorsed calibration methods is shown to be effective with the assessment of laboratory skills and class assignments. Together these studies offer insight into AgNPs future and how to compromise between nanotechnological progress and unfamiliar environmental risks.
Department or Program
Department of Earth and Environmental Sciences
Year Degree Awarded
© 2016, some rights reserved.
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