Identifier

etd-01052013-152253

Degree

Doctor of Philosophy (PhD)

Department

Chemistry

Document Type

Dissertation

Abstract

Group of Uniform Materials Based on Organic Salts (GUMBOS) are a class of molten salts that have been focused to be specifically tailored towards applications. Primitively, from Davy to Walden molten salts were desirable for organic synthesis due to the properties. GUMBOS have been synthesized into nanoparticles (nanoGUMBOS) by various methods to be used for lanthanide luminescence and hyperthermal cancer therapeutics. Lanthanide photochemistry has been frequently studied for its high luminescence intensity, narrow emission band, and stable luminescent lifetime decay. Aerosol-derived europium nanoGUMBOS were characterized using electron microscopy (39.5 ± 8.4 nm), XPS, and spectroscopic techniques. Spectroscopic measurements indicated intense and steady luminescence, which suggests a multitude of possible applications for lanthanide-based GUMBOS, especially in sensory and photovoltaic devices. Several near infrared (NIR) nanoparticles of GUMBOS composed of cationic dyes coupled with biocompatible anions were investigated for their photothermal properties. These nanoparticles were synthesized using a reprecipitation method performed at increasing pH values. The cations for the nanoGUMBOS, [1048] and [1061], have absorbance maxima at wavelengths overlapping with human soft tissue absorbance minima. NIR nanoGUMBOS excited with a 1064 nm continuous laser led to heat generation (20.4 ± 2.7 °C) after five minutes. While the [1061][Deoxycholate] nanoGUMBOS generated the highest temperature increase (23.7 ± 2.4 °C), it was the least photothermally efficient compound (13.0%) due to its relatively large energy band gap of 0.892 eV. The energy band gap is a measurement of the HOMO and LUMO distance, and predictor of photothermal efficiency. The more photothermally efficient compound, [1048][Ascorbate] (64.4%), had a smaller energy band gap of 0.861 eV provided an average photothermal temperature increase of 21.0 ± 2.1 °C. Hyperthermal therapeutics originating from hot pokers has evolved into facilitation of NIR nanomaterials photothermal response. NanoGUMBOS can employ a variety of curative techniques by pairing fluorescent and biocompatible ions. NanoGUMBOS, [1048][Folate] and [1061][Folate], were evaluated using electron microscopy, spectroscopic, thermal imaging, and fluorescent assays. In order to generate highly responsive nanomaterials for NIR-laser-triggered hyperthermia, optimization of nanoparticle size, shape, and uniformity were investigated.

Date

2013

Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

Warner, Isiah M.

Included in

Chemistry Commons

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