Access Type
Open Access Dissertation
Date of Award
January 2015
Degree Type
Dissertation
Degree Name
Ph.D.
Department
Chemistry
First Advisor
Colin F. Poole
Abstract
Determination of distribution levels of environmentally important compounds in various environmental compartments is a major procedure in many fields including environmental risk assessment, food and drug safety, and the perfumery industry. Models for direct estimation of environmental properties were developed using gas chromatography and liquid-liquid partitioning. The developed models were used to derive descriptor values for environmentally important organic compounds. The accuracy of the developed models and descriptor values were demonstrated by the application to the estimation of standard environmental properties and by comparison with experimental solute property values.
Quantitative structure property relationships were constructed for totally organic biphasic partition systems of different polarity containing ethanolamine as the base solvent. The models demonstrate high accuracy and are of good statistical quality. The descriptor space for the determination of the hydrogen bond acidity descriptor was enhanced by the characterization of ethanolamine based partition systems. Models with high statistical quality were also developed for the totally organic biphasic partition systems containing triethylamine as a counter solvent. The triethylamine-formamide system was identified as a suitable system to supplement the currently available totally organic biphasic systems for the determination of the hydrogen bond basicity descriptor.
Descriptor values for polycyclic aromatic hydrocarbons were determined using totally organic biphasic systems and gas and liquid chromatography methods. These descriptors were validated using theoretical models, standard environmental models, and by comparison with experimentally determined values. The descriptor values are homogeneous and accurate as a group. Therefore, the research work reported herein will enable the accurate measurement of solute properties for the estimation of environmental properties.
A substrate-dependent catalytic thermal ALD process was developed to address the low reactivity of precursors in atomic layer deposition processes. The developed process can be used to obtain smooth, high purity thin films at low deposition temperatures, and also for the deposition of materials which were found challenging so far using thermal and energy enhanced atomic layer deposition methods. Substrate-dependent catalytic thermal ALD technique can be conveniently used for the commercial production of thin-film materials. The deposition of pure, uniform and conformal nickel nitride thin films were demonstrated using Ni(OCHMeCH2NMe2)2 precursor, and anhydrous hydrazine in a two-step process, and Ni(OCHMeCH2NMe2)2 precursor, formic acid, and anhydrous hydrazine in a three-step process on ruthenium substrates. Films were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, and atomic force microscopy techniques. The ALD window for the two-step process was observed between 140 and 180 °C with a growth rate of 0.25 Å/cycle. The ALD window for the three-step process was observed between 120 and 180 °C with a growth rate of 0.35Å/cycle. Atomic force microscopy measurements demonstrated smooth thin films for the two-step process which was ~0.25 nm for 25 nm thick films deposited between 120-180 °C. The surface roughness of films varied between 0.38-4.4 nm for 35 nm thick films deposited by three-step process between 120-180 °C.
Recommended Citation
Ariyasena, Thiloka Chandima, "(i)chromatographic Methods For Solute Descriptor Determinations (ii)ruthenium Substrate-Catalyzed Growth Of Nickel Nitride Thin Films By Atomic Layer Deposition" (2015). Wayne State University Dissertations. 1114.
https://digitalcommons.wayne.edu/oa_dissertations/1114