Physical Chemistry Commons^™

The Critical Role Of Mechanism-Based Models For Understanding And Predicting Liposomal Drug Loading, Binding And Release Kinetics, Sweta Modi

Theses and Dissertations--Pharmacy

Liposomal delivery systems hold considerable promise for improvement of cancer therapy provided that critical formulation design criteria can be met. The main objective of the current project was to enable quality by design in the formulation of liposomal delivery systems by developing comprehensive, mechanism-based mathematical models of drug loading, binding and release kinetics that take into account not only the therapeutic requirement but the physicochemical properties of the drug, the bilayer membrane, and the intraliposomal microenvironment.

Membrane binding of the drug affects both drug loading and release from liposomes. The influence of bilayer composition and phase structure on the partitioning ...

Probing The Low Temperature Oxidation Of Furanic Biofuels, 2-Methyltetrahydrofuran And 2,5-Dimethylfuran, Utilizing Orthogonal Time-Of-Flight Mass Spectrometry Coupled To Synchrotron Radiation, Matthew Mcmanus

Master Theses

Concern over natural resources and global climate shifts has increased the focus of sourcing transportation fuels from depleting oil wells to regenerative, biological based solutions. One avenue of biologically sourced fuel involves the extraction of C5 and C6 sugars from the woody, fibrous, and inedible plant materials, otherwise known as lignocellulosic biomass. These cellulosic sugars can be converted to target biofuels and biofuel additives like the furanic compounds, 2,5-dimethylfuran and 2-methylfuran. In this thesis, the low temperature oxidation of two compounds, 2,5-dimethylfuran and 2-methylfuran, are explored. These reactions were conducted at the Advanced Light Source in Berkeley, CA ...

Synthesis Of Isotopologues And Nanoparticles For Hyper Raman Spectroscopy, Burton K. Mandrell

University of Tennessee Honors Thesis Projects

No abstract provided.

Structures And Reactions Of Biomolecules At Interfaces, Xiaoning Zhang

Theses and Dissertations--Chemistry

This dissertation serves to study a protein's conformation-function relationship since immobilized proteins often behave differently from their solution-state counterparts. Therefore, this study is important to the application of protein-based biodevices. Another aim of this dissertation is to explore a new approach to realize low voltage electrowetting without the help of oil bath. Utilizing this approach, a protein micro-separation was realized. Additionally, the interfacial properties of ionic liquid (IL) solid-like layer, which played a key role in electrowetting, was studied for further developments of IL-based applications.

Atomic Force Microscopy (AFM) was utilized in the study and played multiple roles in ...

Nuclear Magnetic Resonance Studies Of Sodiumaluminohexahydride (Na3alh6), Tim J. Ellis-Caleo

Undergraduate Research Symposium

Many applications of modern physics require the investigator to understand the behavior of specific atoms in compounds. The behavior and structure of molecules such as sodiumaluminohexahydride (Na3AlH6) is relevant to the field of hydrogen storage [1]. In this study, we used nuclear magnetic resonance to examine the behavior of sodium, aluminum and hydrogen atoms in the compound sodiumaluminohexahydride. Sodiumaluminohexahydride consists of a covalently bonded AlH6 anion that forms an ionic bond with a sodium cation [2]. Particularly, we investigated the atomic motion at various temperatures by looking at the motional averaging of the atoms as a function of temperature from ...

Second Moment Analysis Of Sodium Aluminohexahydride (Na3alh6) Nmr, Tim J. Ellis-Caleo

Undergraduate Research Symposium

Sodium aluminohexahydride (Na3AlH6) is a promising candidate for reversible hydrogen storage. Understanding the motion of individual atoms within the crystalline lattice is a key challenge of studying hydrogen storage candidates. This molecule is formed by sodium cations and an aluminohexahydride (AlH6-) anion cluster. We examined the relative widths of the lineshapes over the temperature range 23oC to 240oC and noticed significant narrowing, allowing us to conclude that some of the nuclei are moving. It is important to understand not only which nuclei are moving, but also how they are moving. In this case, second moment calculations can be performed to ...

Charge, Bonding, And Magneto-Elastic Coupling In Nanomaterials, Qi Sun

Doctoral Dissertations

Phonons are exquisitely sensitive to finite length scale effects in a wide variety of materials because they are intimately connected to charge, structure, and magnetism, and a quantitative analysis of their behavior can reveal microscopic aspects of chemical bonding and spin-phonon coupling. To investigate these effects, we measured infrared vibrational properties of bulk and nanoscale MoS₂ [molybdenum disulfide], MnO [manganese(II) oxide], and CoFe₂O₄ [cobalt iron oxide]. From an analysis of frequencies, oscillator strengths, and high-frequency dielectric constants, we extracted Born and local effective charges, and polarizability for MoS₂ and MnO. For MoS₂ nanoparticles ...

Density Functional Theory And The Calculation Of Tcmg2O4 Spinel Lattice Parameters, Jon Karlo Macias

Physics

The cohesive energy, lattice constant and bulk modulus of two simple HCP crystal structures of magnesium and technetium were calculated using the vienna ab initio simulation package (VASP) which is based on density functional theory (DFT). The same properties were determined for TcMg₂O₄ spinel. The theoretical results of the lattice constant of the pure crystals were compared to experimental results and found to be in excellent agreement with a difference of less than 2%. The results for the lattice constant of the TcMg₂O₄ spinel were found to be in excellent agreement as well with ...

Efficient Electrochemical Functionalization Of Carbon Nanotubes And Carbon Nanotube Membranes For Energy, Drug Delivery And Potential Catalysis Applications, Xin Zhan

Theses and Dissertations--Chemistry

Electrochemical diazonium grafting offers versatile functionalization of chemically inert graphite under mild condition, which is particularly suitable for CNT composite modification. Tetrafluorinated carboxylphenyl diazonium grafting provides the most controllable functionalization chemistry allowing near monolayer levels of functionality on carbon nanotubes. The functional density was successfully quantified by anion selective dye-assay and X-ray photoelectron spectroscopy (XPS) of thiol-Au self-assembled monolayers (SAM) as a calibration reference. This technique enables monolayer functionality at the tips of carbon nanotube membranes for biomimetic pumps and valves as well as thin conductive layers for CNT-based high area electrochemical support electrodes.

Double-walled carbon nanotube (DWCNT) membranes were ...

Investigation Of The Orientation Dependence On Chiroptical Properties Of Single Molecules, Austin Joseph Cyphersmith

Open Access Dissertations

Optical activity is the defining property of chiral materials that is essential for characterization in biology, chemistry, and physics. While a substantial body of research has provided a strong theoretical framework of the origin of optical activity, we still know very little by way of experiment about an individual molecule’s contribution to the bulk optical activity. The chiroptical response of a single molecule can depend on molecular orientation and local molecular environment, information which is lost in ensemble averaging.

This thesis focuses on establishing methods for a priori determination of chiral molecule orientations and refining measurements to probe the ...

The Bench Synthesis Of Silver Nanostructures Of Variable Size And An Introductory Analysis Of Their Optical Properties, Aoife Power, Anthony J. Betts, John F. Cassidy

Articles

A laboratory practical was designed for use by both undergraduate and second level students to demonstrate the synthesis and characterisation of tuneable silver colloids. It clearly illustrates the novel optical properties of silver nanoparticles compared to the bulk metal. The synthesis is both rapid and repeatable, and can be conducted on the laboratory bench at room temperature.

Experimental And Theoretical Studies In Solid-State Nuclear Magnetic Resonance, Monica N. Kinde

Student Research Projects, Dissertations, and Theses - Chemistry Department

Solid-state nuclear magnetic resonance (SSNMR) has proven to be a powerful tool for probing molecular structure and dynamics. Deuterium SSNMR is particularly useful due to the presence of anisotropic interactions whose motional averaging contributes structural and dynamical insight. The magnitude and type of molecular motion can be determined from analysis of solid echo deuterium lineshapes and/or relaxation studies. This work uses various applications of solid-state NMR as well as ab initio and density functional computational methods to study three different areas of physical chemistry: biophysical chemistry, materials science and fundamental concepts of physical chemistry. The first project addressed the ...

Structure And Chemistry Of Model Catalysts In Ultrahigh Vacuum, Joshua D. Walker

Theses and Dissertations

The study of catalysis is a key area of focus not only in the industrial sector but also in the nature and biological systems. The market for catalysis is a multi-billion dollar industry. Many of the materials and products we use on a daily basis are formed through a catalytic process. The quest to understanding and improving catalytic mechanisms is ongoing. Many model catalysts use transition metals as a support for chemical reactions to take place due to their selectivity and activity. Palladium, gold, and copper metals are studied in this work and show the ability to be catalytically reactive ...

Theory Of Model Kohn-Sham Potentials And Its Applications, Alex P. Gaiduk

Electronic Thesis and Dissertation Repository

The purpose of Kohn-Sham density functional theory is to develop increasingly accurate approximations to the exchange-correlation functional or to the corresponding potential. When one chooses to approximate the potential, the resulting model must be integrable, that is, a functional derivative of some density functional. Non-integrable potentials produce unphysical results such as energies that are not translationally or rotationally invariant. The thesis introduces methods for constructing integrable model potentials, developing properly invariant energy functionals from model potentials, and designing model potentials that yield accurate electronic excitation energies. Integrable potentials can be constructed using powerful analytic integrability conditions derived in this work ...

X-Ray Absorption Fine Structure And X-Ray Excited Optical Luminescence Studies Of Gallium Nitride - Zinc Oxide Solid Solution Nanostructures, Matthew J. Ward

Electronic Thesis and Dissertation Repository

Gallium nitride – zinc oxide (GaN-ZnO) solid solutions have been realized as potential photocatalysts for overall water splitting due to a narrowing of the band-gap into the visible region of the solar spectrum. Although there has been much experimental and theoretical work on this novel class of semiconductors many questions about the nature of their electronic and chemical properties remain unanswered. In particular the mechanism of band-gap reduction in these materials is not clearly understood. It is also unclear what the local chemical environment of gallium, zinc, nitrogen, and oxygen is in both the surface and bulk of these solid solutions ...

A Study Of Gamma Radiation Induced Carbon Steel Corrosion, Kevin Daub

Electronic Thesis and Dissertation Repository

This thesis presents work on the development of a mechanistic understanding of the effect of ionizing radiation on the aqueous corrosion kinetics of carbon steel. Exposed to ionizing radiation, water decomposes into a range of oxidizing (O₂, •OH, HO₂•, H₂O₂) to reducing (•e_aq^–, •O₂^–, •H) species. The production of the redox active species by radiolysis can have a significant effect on the corrosion behaviour of a metal. Of particular interest is the effect of radiolysis on corrosion when the solution environment, such as temperature, pH, and concentrations of chemical additives, changes over time ...

Nonlinear Light Propagation And Self-Inscription Processes In A Photopolymer Doped With Ag Nanoparticles, Liqun Qiu

Open Access Dissertations and Theses

The resonance of surface plasmons on metal nanoparticles can be excited at visible wavelengths. The extraordinary enhancement of a variety of optical phenomena in the vicinity of metal nanoparticles has been attributed to the strong fields generated under resonance conditions. As a result, extensive research has been carried out to incorporate the extraordinary optical properties of metal nanoparticles into optical devices and applications, ranging from spectroscopy (e.g, surface enhanced Raman, IR and Fluorescence), optical sensing and imaging, to photovoltaic cells, photonic crystals and optical switches. Particular effort has been directed towards producing stable dispersion of metal nanoparticles within soft ...

Studies Of Microscopic Scale Strains In Nickel Alloys Resulting From Mechanical And Chemical Forces, Jing Chao

Electronic Thesis and Dissertation Repository

The nickel-based Alloy 600, also known as Inconel 600 has been found to be susceptible to stress corrosion cracking (SCC) in high temperature aqueous environments. Despite extensive research, the mechanisms by which this process occurs remain in question. It is known that SCC results from the simultaneous effects of a chemically corrosive environment and a tensile stress. Many studies have been conducted on the microscopic chemical changes associated with SCC. There have been fewer studies of the microscopic stress/strain process. The main objective of this thesis is to use the new x-ray based diffraction technique – polychromatic x-ray microdiffraction (PXM ...

The Influence Of Auxiliary Ligands On The Photophysical Characteristics Of A Series Of Ruthenium (Ii) Polypyridyl Complexes, Luke O'Neill, Laura Perdisatt, Christine O'Connor

Articles

A series of ruthenium polypyridyl complexes were studied using UV/Vis absorption and luminescence spectroscopy as well as luminescence lifetime determination by time correlated single photon counting (TCSPC). The complexes were characterised with regard to the variation in the electronic band-gap as a result of the sequential variation of the auxiliary ligand 2,2’-bipyridine (bpy), 1,10-phenanthroline (phen) and 2,2’-biquinoline (biq) ligands while the main ligand remained constant for three different main ligand types. Luminescence yields were calculated and correlated with structural and electronic variation. It was found that both the absorption and emission characteristics could be ...

Kinetics And Thermodynamics Of (1+2) Cycloadditions Of Transient Diphenylgermylene With Alkenes, Yaser Saeidi Hayeniaz

Open Access Dissertations and Theses

1,1-Dimethyl-3-phenyl-1-germacyclopent-3-ene (32) was synthesized and it was used for the study of the reactivity of diphenylgermylene (GePh₂) toward alkenes using steady state and nanosecond laser flash photolysis technique (nLFP) in hexanes solution.

The reactivity of GePh₂ toward several alkenes including 1-hexene, cis-2-hexene, trans- 3-hexene, cyclopentene, cyclohexene, cis-cyclooctene, methylcyclohexene, 2-methyl-2- pentene, 2-methyl-1-pentene and trans-3-methyl-2-pentene has been investigated by nLFP method. In all cases, the equilibrium constant was measured and it was found that there is a direct correlation between the Gibbs free energy of the reaction (∆G_r) and the ionization potential (IP) of the involved alkene. This ...