Date of Award

Spring 5-6-2022

Level of Access Assigned by Author

Open-Access Thesis

Degree Name

Doctor of Philosophy (PhD)

Department

Chemistry

Advisor

Carl P. Tripp

Second Committee Member

Alice Bruce

Third Committee Member

William Gramlich

Additional Committee Members

Douglas Bousfield

Mark Wells

Abstract

The underlying concepts developed in this thesis involve particulate fabrication of known size using a bottom-up synthesis or a top-down milling process. This bottom-up approach was used for detection of analytes in water. Conventional UV-Vis spectroscopic based detection methods require target analytes to be soluble or have enough vapor pressure for analysis in the gas phase. We achieved an order in magnitude improvement in the detection limit over the standard molybdenum blue method for phosphate and arsenate by conversion of target analytes present in solution to a solid for quantification by UV-Vis and IR spectroscopy. Furthermore, by recording a visible and infrared spectrum on the same membrane, we were able to selectively determine both phosphate and arsenate. This is not possible using the standard molybdenum blue method. We also developed generalized approach involved the precipitation of polyatomic anions with simple monoatomic cations. We demonstrated this concept with the detection of free and weak acid dissociative (WAD) cyanide in water. In our method, cyanide ions are precipitated with silver ions and then captured on an IR transparent membrane. Key to our approach was the use of an 13CN spiked addition to achieve detection limits below the 0.2 mgL-1 level. Furthermore, we were able to distinguish between free and WAD cyanide by using a spiked addition of sodium sulfide. The sulfide freed the cyanide from the WAD compounds enabling detection of this fraction of cyanide by our method. Using a tops-down approach we generated bismuth telluride nanoparticles for thermoelectric power generation. The “as received” bismuth telluride ingots were ball milled in the presence of the cationic polymer PADAMAc which prevented particle aggregation during the milling process. By adjusting the milling conditions, we were able to control the particle size of the particulate to a small as 40 nm in diameter. Sintering pellets of the particulates below the melting point resulted in voids that scattered the thermal radiation. As a result, we show that adjusting particle size and sintering temperature could be viable strategies for developing TE material.

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