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Thermochemical investigations of crystalline solutes in non-electrolyte solutions: Mathematical representation of solubility data and the development of predictive solubility equations in systems with specific and non-specific interactions.

Understanding the thermodynamic properties of multicomponent mixtures is of critical importance in many chemical and industrial applications. Experimental measurements become progressively difficult as the number of solution components increases -- producing the need for predictive models. Problems in development of predictive models arise if the mixture has one or more components that interact through molecular complexation or association. Experimental solubilities of anthracene and pyrene di… more

Date: May 2008

Creator: Zvaigzne, Anita Ilze

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

Predicting Chemical and Biochemical Properties Using the Abraham General Solvation Model

Several studies were done to illustrate the versatillity of the Abraham model in mathematically describing the various solute-solvent interactions found in a wide range of different chemical and biological systems. The first study focused on using the solvation model to construct mathematical correlations describing the minimum inhibitory concentration of organic compounds for growth inhibition towards the three bacterial strains Porphyromonas gingivalis, Selenomonas artemidis, and Streptococc… more

Date: May 2009

Creator: Mintz, Christina

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

Affordances of Instrumentation in General Chemistry Laboratories

The purpose of this study is to find out what students in the first chemistry course at the undergraduate level (general chemistry for science majors) know about the affordances of instrumentation used in the general chemistry laboratory and how their knowledge develops over time. Overall, students see the PASCO system as a useful and accurate measuring tool for general chemistry labs. They see the probeware as easy to use, portable, and able to interact with computers. Students find that the … more

Date: August 2010

Creator: Sherman, Kristin Mary Daniels

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

Substitution Chemistry of Ruthenium Clusters with the Diphosphine Ligands: 4,5-Bis(Diphenylphosphino)-4-Cyclo-Penten-1,3-Dione (bpcd), (Z)-Ph₂PCH=CHPP₂ and 3,4-Bis(Diphenylphosphino)-5-Methoxy-2(5H)-Furanone (bmf)

The chemistry of transition metal clusters has been a fast developing area of organometallic research in recent years. Compared to mononuclear metal complexes, polynuclear clusters offer more opportunities to study cooperative effects and electron reservoir properties between contiguous metal centers, in addition to functioning as storehouses for the release of catalytically active small fragments capable of exhibiting heterosite subtrate activation. Theoretically, metal clusters are intermedia… more

Date: May 1997

Creator: Shen, Huafeng

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

Synthesis and Electron Transfer Studies of Supramolecular Triads

This study expands the role of polythiophenes as an electron donating chromophore within energy harvesting milti-modular donor-acceptor systems. The polythiophene moiety would act as an electron donating spacer group between the donor and acceptor entities, viz., phenothiazine and fulleropyrrolidine, respectively, in the newly synthesized supramolecular triads. The triads 10-{[2,2';5',2"] terthiophene-5-fulleropyrrolidine} phenothiazine and 10-{[2,2'] bithiophene-5-fulleropyrrolidine} phenothia… more

Date: May 2016

Creator: Bodenstedt, Kurt

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

Tantalum- and ruthenium-based diffusion barriers/adhesion promoters for copper/silicon dioxide and copper/low κ integration.

The TaSiO6 films, ~8Å thick, were formed by sputter deposition of Ta onto ultrathin SiO2 substrates at 300 K, followed by annealing to 600 K in 2 torr O2. X-ray photoelectron spectroscopy (XPS) measurements of the films yielded a Si(2p) binding energy at 102.1 eV and Ta(4f7/2) binding energy at 26.2 eV, indicative of Ta silicate formation. O(1s) spectra indicate that the film is substantially hydroxylated. Annealing the film to > 900 K in UHV resulted in silicate decomposition to SiO2 and Ta2… more

Date: December 2004

Creator: Zhao, Xiaopeng

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

Elucidation of Photoinduced Energy and Electron Transfer Mechanisms in Multimodular Artificial Photosynthetic Systems

Multimodular designs of electron donor-acceptor systems are the ultimate strategy in fabricating antenna-reaction center mimics for artificial photosynthetic applications. The studied photosystems clearly demonstrated efficient energy transfer from the antenna system to the primary electron donor, and charge stabilization of the radical ion pair achieved with the utilization of secondary electron donors that permits either electron migration or hole transfer. Moreover, the molecular arrangement… more

Date: May 2017

Creator: Lim, Gary Lloyd

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

Electrodeposition of Molybdenum-Based Coatings from Aqueous Alkaline Solutions for Enhanced Corrosion Resistance

Zn-Mo coatings are very promising environment friendly anticorrosive coatings as replacement materials for cadmium and chromium (VI) based conversion layers. Electrodeposition has become a favorable technique in fabricating coatings due to its low cost, ease of use, and overall experimental control of coating quality. Very little research so far has been done for the electrodeposition of Zn-Mo coatings under alkaline conditions. In this work, Zn and Zn-Mo coatings were electrochemically deposit… more

Date: May 2018

Creator: Zhou, Ting

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

Thermochemistry Investigations Via the Correlation Consistent Composite Approach

Since the development of the correlation consistent composite approach (ccCA) in 2006, ccCA has been shown to be applicable across the periodic table, producing, on average, energetic properties (e.g., ionization potentials, electron affinities, enthalpies of formation, bond dissociation energies) within 1 kcal/mol for main group compounds. This dissertation utilizes ccCA in the investigation of several chemical systems including nitrogen-containing compounds, sulfur-containing compounds, and c… more

Date: December 2012

Creator: Jorgensen, Kameron R.

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

Characterization of Novel Solvents and Absorbents for Chemical Separations

Predictive methods have been employed to characterize chemical separation mediums including solvents and absorbents. These studies included creating Abraham solvation parameter models for room-temperature ionic liquids (RTILs) utilizing novel ion-specific and group contribution methodologies, polydimethyl siloxane (PDMS) utilizing standard methodology, and the micelles cetyltrimethylammonium bromide (CTAB) and sodium dodecylsulfate (SDS) utilizing a combined experimental setup methodology with … more

Date: May 2011

Creator: Grubbs, Laura Michelle Sprunger

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

Free Radical Induced Oxidation, Reduction and Metallization of NiSi and Ni(Pt)Si Surfaces

NiSi and Ni(Pt)Si, and of the effects of dissociated ammonia on oxide reduction was carried out under controlled ultrahigh vacuum (UHV) conditions. X-ray photoelectron spectroscopy (XPS) has been used to characterize the evolution of surface composition. Vicinal surfaces on NiSi and Ni(Pt)Si were formed in UHV by a combination of Ar+ sputtering and thermal annealing. Oxidation of these surfaces in the presence of either O+O2 or pure O2 at room temperature results in the initial formation of a S… more

Date: August 2010

Creator: Manandhar, Sudha

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

Diffusion Barriers/Adhesion Promoters. Surface and Interfacial Studies of Copper and Copper-Aluminum Alloys

The focus of this research is to study the interaction between copper and the diffusion barrier/adhesion promoter. The behavior of copper sputter-deposited onto sputter-cleaned tantalum nitride is investigated. The data show that copper growth on tantalum nitride proceeds with the formation of 3-D islands, indicating poor adhesion characteristics between copper and Ta0.4N. Post-annealing experiments indicate that copper will diffuse into Ta0.4N at 800 K. Although the data suggests that Ta0.4N i… more

Date: August 2000

Creator: Shepherd, Krupanand Solomon

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

A Quenchofluorometric Study of Polycyclic Aromatic Hydrocarbons in Molecularly Organized Media

Detection, identification and separation of polycyclic aromatic compounds in environmental samples are of extreme importance since many of these compounds are well known for their potential carcinogenic and/or mutagenic activities. Selective quenching of molecular fluorescence can be utilized effectively to analyze mixtures containing different polycyclic aromatic hydrocarbons. Molecularly organized assemblies are used widely in detection and separation of these compounds mainly because of less… more

Date: May 1998

Creator: Pandey, Siddharth

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

Characterization of Low Barrier Hydrogen Bonds in Enzyme Catalysis: an Ab Initio and DFT Investigation

Hartree-Fock, Moller-Plesset, and density functional theory calculations have been carried out using 6-31+G(d), 6-31+G(d,p) and 6-31++G(d,p) basis sets to study the properties of low-barrier or short-strong hydrogen bonds (SSHB) and their potential role in enzyme-catalyzed reactions that involve proton abstraction from a weak carbon-acid by a weak base. Formic acid/formate anion, enol/enolate and other complexes have been chosen to simulate a SSHB system. These complexes have been calculated to… more

Date: August 1999

Creator: Pan, Yongping

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

Podcast Effectiveness as Scaffolding Support for Students Enrolled in First-Semester General Chemistry Laboratories

Podcasts covering essential first-semester general chemistry laboratory techniques and central concepts that aid in experimental design or data processing were prepared and made available for students to access on an as-needed basis on iPhones- or iPod touches-. Research focused in three areas: the extent of podcast usage, the numbers and types of interactions between instructors and research teams, and student performance on graded assignments. Data analysis indicates that the podcast treatmen… more

Date: August 2010

Creator: Powell, Mary Cynthia Barton

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

Characterization of Post-Plasma Etch Residues and Plasma Induced Damage Evaluation on Patterned Porous Low-K Dielectrics Using MIR-IR Spectroscopy

As the miniaturization of functional devices in integrated circuit (IC) continues to scale down to sub-nanometer size, the process complexity increases and makes materials characterization difficult. One of our research effort demonstrates the development and application of novel Multiple Internal Reflection Infrared Spectroscopy (MIR-IR) as a sensitive (sub-5 nm) metrology tool to provide precise chemical bonding information that can effectively guide through the development of more efficient … more

Date: May 2016

Creator: Rimal, Sirish

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

Interfacial Electrochemistry and Surface Characterization: Hydrogen Terminated Silicon, Electrolessly Deposited Palladium & Platinum on Pyrolyzed Photoresist Films and Electrodeposited Copper on Iridium

Hydrogen terminated silicon surfaces play an important role in the integrated circuit (IC) industry. Ultra-pure water is extensively used for the cleaning and surface preparation of silicon surfaces. This work studies the effects of ultra-pure water on hydrogen passivated silicon surfaces in a short time frame of 120 minutes using fourier transform infrared spectroscopy – attenuated total reflection techniques. Varying conditions of ultra-pure water are used. This includes dissolved oxygen poor… more

Date: December 2003

Creator: Chan, Raymond

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

Substitution Chemistry of the Cobalt Complexes [Co₂(CO)₆(PhC≡CR) (R=Ph, H) and PhCCo₃(CO)₉] with the Diphosphine Ligands [Bis(diphenylphosphino)maleic Anhydride (BMA) and (Z)-Ph₂PCH=CHPPh₂]. Reversible Chelate-to-Bridge Diphosphine Ligand Exchange, Phosphorus-Carbon Bond Cleavage and Phosphorus-Carbon Bond Formation

The tricobalt cluster PhCCo3(CO)9 (1) reacts with the bidentate phosphine ligand 2,3-bis(diphenylphosphino)maleic anhydride (bma) in the presence of added Me3NO to give the diphosphine-substituted cluster PhCCo3(CO)7(bma) (2). Cluster 2 is unstable in solution, readily losing CO to afford Co3(CO)6[(μ2-η2/η1-C(Ph)C=C(PPh2)C(O)OC(O)](μ2-PPh2) (3) as the sole observed product. VT-31P NMR measurements on cluster 2 indicate that the bma ligand functions as both a chelating and a bridging ligand. At … more

Date: December 1994

Creator: Yang, Kaiyuan

Item Type: Thesis or Dissertation

Partner: UNT Libraries

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Examining and Characterizing Changes in First Year High School Chemistry Curricula

Many students currently entering college are able to solve mathematical problems but often do not understand the chemistry concepts underlying their calculations. High school chemistry teachers from Texas and the United States (US) were surveyed as to what topics they teach in their chemistry classes. A subset of Texas teachers was also interviewed about their instruction. The survey indicated that less-experienced Texas teachers are omitting a number of topics from their chemistry instruction,… more

Date: August 2010

Creator: Holley, Kerry Kathleen McGee

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

Investigation of Post-Plasma Etch Fluorocarbon Residue Characterization, Removal and Plasma-Induced Low-K Damage for Advanced Interconnect Applications

Modern three-dimensional integrated circuit design is rapidly evolving to more complex architecture. With continuous downscaling of devices, there is a pressing need for metrology tool development for rapid but efficient process and material characterization. In this dissertation work, application of a novel multiple internal reflection infrared spectroscopy metrology is discussed in various semiconductor fabrication process development. Firstly, chemical bonding structure of thin fluorocarbon … more

Date: May 2016

Creator: Mukherjee, Tamal

Item Type: Thesis or Dissertation

Partner: UNT Libraries

The Revival of Electrochemistry: Electrochemical Deposition of Metals in Semiconductor Related Research

Adherent Cu films were electrodeposited onto polycrystalline W foils from purged solutions of 0.05 M CuSO4 in H2SO4 supporting electrolyte and 0.025 M CuCO3∙Cu(OH)2 in 0.32 M H3BO3 and corresponding HBF4 supporting electrolyte, both at pH = 1. Films were deposited under constant potential conditions at voltages between -0.6 V and -0.2 V versus Ag/AgCl. All films produced by pulses of 10 s duration were visible to the eye, copper colored, and survived a crude test called "the Scotch tape test… more

Access: Restricted to the UNT Community Members at a UNT Libraries Location.

Date: August 2005

Creator: Wang, Chen

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

Surface Chemical Deposition of Advanced Electronic Materials

The focus of this work was to examine the direct plating of Cu on Ru diffusion barriers for use in interconnect technology and the substrate mediated growth of graphene on boron nitride for use in advanced electronic applications. The electrodeposition of Cu on Ru(0001) and polycrystalline substrates (with and without pretreatment in an iodine containing solution) has been studied by cyclic voltammetry (CV), current-time transient measurements (CTT), in situ electrochemical atomic force microsc… more

Date: December 2010

Creator: Bjelkevig, Cameron

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

Fundamental Studies of Copper Bimetallic Corrosion in Ultra Large Scale Interconnect Fabrication Process

In this work, copper bimetallic corrosion and inhibition in ultra large scale interconnect fabrication process is explored. Corrosion behavior of physical vapor deposited (PVD) copper on ruthenium on acidic and alkaline solutions was investigated with and without organic inhibitors. Bimetallic corrosion screening experiments were carried out to determine the corrosion rate. Potentiodynamic polarization experiments yielded information on the galvanic couples and also corrosion rates. XPS and FTI… more

Date: May 2014

Creator: Koskey, Simon Kibet

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

The Development of Predictive Models for the Acid Degradation of Chrysotile Asbestos

The purpose of this study was to determine the factors affecting the acid degradation of chrysotile asbestos (Mg_3Si_2O_5(OH_4)) . Millions of tons of asbestos have found use in this country as insulative or ablative material. More than 95 percent of the asbestos in use is of the chrysotile variety. The remaining 5 percent is composed of various types of fibrous amphiboles. The inhalation of asbestos can lead to several diseases in humans. Asbestosis, lung cancer and mesothelioma are the most c… more

Date: May 1993

Creator: Ingram, Kevin D. (Kevin Dean)

Item Type: Thesis or Dissertation

Partner: UNT Libraries