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You searched for +publisher:"Clemson University" +contributor:("Dr. Christopher L. Kitchens, Committee Chair"). Showing records 1 – 2 of 2 total matches.

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Clemson University

1. Coral, Jason Alan. Measuring and Predicting Hydroxyl Radical Generation From Irradiated TiO2 Nanoparticles Under Simulated Environmental Conditions and Correlations to <i>Daphnia magna</i> Toxicity.

Degree: PhD, 2018, Clemson University

Interest in inclusion of titanium dioxide nanoparticles in a multitude of industrial and personal products has driven production over the past two decades. Concurrent with increases in nanoparticle production, an increase in nanoparticle movement from use to environment can be expected. Particular concern is focused on TiO2 nanoparticles moving to freshwater compartments. Inherent photocatalytic nanoparticle properties generate reactive oxygen species upon exposure to water, oxygen, and ultraviolet light. While this particular feature is utilized for surface-cleaning and pollution mitigating applications, it poses a significant risk to organisms exposed to these nanoparticles. This risk can be difficult to quantify, exhibited by the variation in toxicity reports from various labs. These variations are a result of differing conditions. Environmental factors such as presence of natural organic matter (NOM), intensity of ultraviolet (UV) light, and the wavelengths of UV light exposure will affect toxicity as well as physical characteristics of the nanoparticle, including size and crystallinity. These variations impart uncertainty to toxicity measurements creating a knowledge gap regarding conditional effects acting on TiO2 to modulate toxicity. The goal of the present research was to develop a comprehensive understanding of the effects that environmentally relevant conditions have on TiO2 radical generation and correlate these conditionally affected rate changes to toxicity measurements. To accomplish these goals, a systematic approach of a full factorial exposure design to quantify the interacting effects of simulated environmental conditions on irradiated TiO2 nanoparticles at eight TiO2 concentrations, five NOM concentrations (measured as dissolved organic carbon), and four UV-A intensities was utilized. Radicals generated by irradiated TiO2 were characterized as hydroxyl radicals using Electron Paramagnetic Resonance spectroscopy. The exposure conditions were characterized and compared to existing literature and natural conditions. The changes in hydroxyl radical generation rates were monitored using fluorescence spectroscopy. Linear regression techniques were used to determine how the conditional effects regulated hydroxyl generation rate. A number of trends were well correlated with conditions. Rate of hydroxyl generation was positively correlated with concentration of TiO2 nanoparticles as a result of increased total available surfaces for photon impingement. Increases in light intensity were likewise positively correlated to increases in hydroxyl generation rate, a result of a greater number of photons interacting with the nanoparticle surface. The reciprocal interaction of these conditions demonstrates classic phototoxic behavior wherein a low concentration of TiO2 and a high intensity of UV-A generates an equivalent response compared to high concentrations of TiO2 and low intensities of UV-A. This reciprocal effect is complicated by the addition of NOM. Increasing total amounts of NOM to suspensions… Advisors/Committee Members: Dr. Christopher L. Kitchens, Committee Chair, Dr. Stephen J. Klaine, Dr. Julia Brumaghim, Dr. Elizabeth Carraway, Dr. Aaron Roberts.

Subjects/Keywords: Daphnia magna; Generation Rate; Hydroxyl Radical; Nanoparticles; Titanium Dioxide

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Coral, J. A. (2018). Measuring and Predicting Hydroxyl Radical Generation From Irradiated TiO2 Nanoparticles Under Simulated Environmental Conditions and Correlations to <i>Daphnia magna</i> Toxicity. (Doctoral Dissertation). Clemson University. Retrieved from https://tigerprints.clemson.edu/all_dissertations/2158

Chicago Manual of Style (16th Edition):

Coral, Jason Alan. “Measuring and Predicting Hydroxyl Radical Generation From Irradiated TiO2 Nanoparticles Under Simulated Environmental Conditions and Correlations to <i>Daphnia magna</i> Toxicity.” 2018. Doctoral Dissertation, Clemson University. Accessed October 31, 2020. https://tigerprints.clemson.edu/all_dissertations/2158.

MLA Handbook (7th Edition):

Coral, Jason Alan. “Measuring and Predicting Hydroxyl Radical Generation From Irradiated TiO2 Nanoparticles Under Simulated Environmental Conditions and Correlations to <i>Daphnia magna</i> Toxicity.” 2018. Web. 31 Oct 2020.

Vancouver:

Coral JA. Measuring and Predicting Hydroxyl Radical Generation From Irradiated TiO2 Nanoparticles Under Simulated Environmental Conditions and Correlations to <i>Daphnia magna</i> Toxicity. [Internet] [Doctoral dissertation]. Clemson University; 2018. [cited 2020 Oct 31]. Available from: https://tigerprints.clemson.edu/all_dissertations/2158.

Council of Science Editors:

Coral JA. Measuring and Predicting Hydroxyl Radical Generation From Irradiated TiO2 Nanoparticles Under Simulated Environmental Conditions and Correlations to <i>Daphnia magna</i> Toxicity. [Doctoral Dissertation]. Clemson University; 2018. Available from: https://tigerprints.clemson.edu/all_dissertations/2158


Clemson University

2. Hart, Ashley E. Synthesis, Design, and Environmental Fate of Metallic Nanoparticles.

Degree: PhD, Chemical Engineering, 2014, Clemson University

Rational design of nanoparticle surface chemistry offers the ability to control nanoparticle characteristics such as size, polydispersity, shape, dispersibility in various solvents, functionality and end fate. Ligand exchange has proved to be is a versatile method for modifying the surface of plasmonic nanoparticles. Ligand exchange has provided a “green” alternative to traditional biphasic syntheses that require large amounts of phase transfer catalysts. Ligand exchange can also be used to reduce the amount of post synthesis processing and waste when it is conducted on nanoparticles that have been synthesized with a method that affords control over nanoparticle size and polydispersity. Ligand exchange is also an important reaction to consider when determining the end fate of nanomaterials due to the fact that when nanoparticles enter the natural environment, they will be exposed to a variety of natural ligands and electrolytes. We have conducted a comprehensive review of ligand exchange literature and used isothermal titration calorimetry to investigate ligand binding and exchange on gold nanoparticles experimentally. We have also investigated the impact that citrate and natural organic matter surface chemistries have on the transport properties of silver nanoparticles. This work has led to a greater understanding of the influencing factors on the mechanism of nanoparticle ligand binding and exchange. Advisors/Committee Members: Dr. Christopher L. Kitchens, Committee Chair, Dr. David Bruce, Dr. Mark Roberts, Dr. Brian A. Powell, Dr. O. Thompson Mefford.

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Hart, A. E. (2014). Synthesis, Design, and Environmental Fate of Metallic Nanoparticles. (Doctoral Dissertation). Clemson University. Retrieved from https://tigerprints.clemson.edu/all_dissertations/1784

Chicago Manual of Style (16th Edition):

Hart, Ashley E. “Synthesis, Design, and Environmental Fate of Metallic Nanoparticles.” 2014. Doctoral Dissertation, Clemson University. Accessed October 31, 2020. https://tigerprints.clemson.edu/all_dissertations/1784.

MLA Handbook (7th Edition):

Hart, Ashley E. “Synthesis, Design, and Environmental Fate of Metallic Nanoparticles.” 2014. Web. 31 Oct 2020.

Vancouver:

Hart AE. Synthesis, Design, and Environmental Fate of Metallic Nanoparticles. [Internet] [Doctoral dissertation]. Clemson University; 2014. [cited 2020 Oct 31]. Available from: https://tigerprints.clemson.edu/all_dissertations/1784.

Council of Science Editors:

Hart AE. Synthesis, Design, and Environmental Fate of Metallic Nanoparticles. [Doctoral Dissertation]. Clemson University; 2014. Available from: https://tigerprints.clemson.edu/all_dissertations/1784

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