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Local Structure And Dynamic Studies Of Mixed Ch4-Co2 Gas Hydrates Via Computational Simulation And Neutron Scattering, Bernadette Rita Cladek

Doctoral Dissertations

Permeated throughout the ocean floor and arctic permafrost, natural gas hydrates contain an estimated 3000 trillion cubic meters, over three times that of traditional shale deposits, of CH₄ that is accessible for extraction. Gas hydrates are a crystal structure in which water molecules form a cage network, the host, through hydrogen bonds while trapping a guest molecule such as CH₄ in the cavities. These compounds form naturally where the appropriate low temperature and high pressure conditions occur. A promising and tested method of methane recovery is through exchange with CO₂, which energetically takes place of the …

Unifying Chemistry And Machine Learning For The Study Of Noncovalent Interactions, Jacob A. Townsend

Doctoral Dissertations

Gas separations are in great demand for carbon emission reduction, natural gas purification, oxygen isolation, and much more. Many of these separations rely on cost-prohibitive methods such as cryogenic distillation or strong-binding solvents. As a result, novel materials are being developed to subvert the energetic expense of gas separation processes. These studies focus on improving the performance of alternative materials, including (but not limited to) metal-organic frameworks, covalent organic frameworks, dense polymeric membranes, porous polymers, and ionic liquids.

In this work, the atomistic effects of functional units are explored for gas separations processes using electronic structure theory and machine learning. …

Using Second Harmonic Generation To Study Gram-Positive Bacterial Membranes, Lindsey N. Miller

Doctoral Dissertations

Understanding how small-molecules, such as drugs, interact with bacterial membranes can quickly unravel into much more perplexing questions. No two bacterial species are alike, especially when comparing their membrane compositions which can even be altered by incorporating fatty acids from their surrounding environment into their lipid-membrane composition. To further complicate the comparison, discrete alterations in small-molecule structures can result in vastly different membrane-interaction outcomes, giving rise to the need for more "label-free" studies when analyzing drug mechanisms. The work presented in this dissertation highlights the benefits to using nonlinear spectroscopy and microscopy techniques for probing small-molecule interactions in living bacteria. …

Bioanalytical Applications Of Digital Imaging: Applications To Organ-On-Chip And Point-Of-Care Analysis Systems, Amirus Saleheen

Doctoral Dissertations

Qualitative and quantitative analysis through digital imaging has significant potential in several scientific applications including bioanalytical applications. In this document, the implication of digital imaging to validate and characterize a novel microfluidic organ-on-chip device and establish a point-of-care method to estimate epinephrine concentrations in expired and degraded autoinjectors have been described in chapter 2 and 3 respectively. Chapter 4 includes description of the principle and methodology of strong cation exchange-based immunoassay for oxytocin and β-endorphin.

In chapter 2, fabrication of a novel microfluidic organ-on-chip device capable of culturing rodent SCN slices has been discussed. Characterization of the aCSF media droplets …

Lithium-Aluminum Layered Double Hydroxide Chlorides: Structural And Thermodynamic Studies To Understand Dynamics, Functionality, And Applications In Lithium Adsorption, Samuel Frederi Evans

Doctoral Dissertations

No abstract provided.

Providing Insight To Enable The Design Of Tailored, Nano-Structured Polymeric Surfaces And Interfaces, Onome J. Agori-Iwe

Doctoral Dissertations

Methods are presented for modifying polymeric material surfaces using: 1) selective surface segregation in binary branched/linear polymer blends, and 2) surface functionalization with polymer brushes. Using neutron reflectivity, elastic recoil detection, and other complementary techniques, the aim was to identify structure-property relationships and provide fundamental insight into the time evolution and formation of surfaces and interfaces in these materials.

In blends of poly(styrene) (PS) HyperMacs and DendriMacs in a linear deuterated PS (d-PS) matrix, smaller hyperbranched additives (<1E6 g/mol) move slower than their linear analogues. Larger (>1E6 g/mol) and less flexible hyperbranched additives with smaller fractal dimensions move faster than their linear analogues, suggesting that they are less …

Dually Responsive Shape-Changing Linear And Star Molecular Bottlebrushes With Bicomponent Side Chains, Ethan Wesley Kent

Doctoral Dissertations

Molecular bottlebrushes (MBBs) can exhibit large conformational changes from wormlike to globular in solution in response to environmental stimuli. However, the instability of the collapsed state has prevented shape-changing MBBs from potential applications in, e.g., biomimetic catalysis and substance delivery. This dissertation work focused on dually responsive linear and star MBBs composed of bicomponent side chains in the form of either homografted diblock copolymer or binary heterografted polymeric side chains. When one polymer component collapsed, driving the shape changing of MBBs, another component served as a stabilizer. When both components in the side chains were stimuli-responsive, an additional level of …