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Full-Text Articles in Physical Sciences and Mathematics

Metal-Oxide Nanostructures Fabricated From Reactive Laser Ablation In Liquid, Mallory G. John Jan 2020

Metal-Oxide Nanostructures Fabricated From Reactive Laser Ablation In Liquid, Mallory G. John

Theses and Dissertations

The development of metal-oxide nanostructures is a growing area due to their applications in diverse fields spanning energy conversion and storage, chemical manufacturing, and en- vironmental technology. This interest in catalytically active nanomaterials has prompted the synthesis and investigation of highly functionalized nanoparticles (NPs), including core- shell, silicate-stabilized, and bi- and multi-metallic nanocomposites. While wet-chemical synthesis methods of metal-oxide nanostructures have led to several morphologies, compositions, and shapes, these syntheses often require high temperatures, toxic solvents or reducing agents, and long reaction times.

Laser synthesis and processing of colloids (LSPC) encompasses both ‘top down’ and ‘bottom up’ approaches to synthesize …


Probing Vibrational Wave Packets In Organophoshorous Molecules Using Femtosecond Time-Resolved Mass Spectrometry (Ftrms), Derrick Ampadu Boateng Jan 2020

Probing Vibrational Wave Packets In Organophoshorous Molecules Using Femtosecond Time-Resolved Mass Spectrometry (Ftrms), Derrick Ampadu Boateng

Theses and Dissertations

The study of organophosphorus and nitroaromatic compounds is essential due to their suitability as models for understanding the dynamics of radiation induce damage to DNA sugar-phosphate backbone, and the detection of chemical warfare agents as well as nitroaromatic explosives (such as TNT). The ultrafast dynamics of these polyatomic radicals were studied using femtosecond time-resolved mass spectrometry (FTRMS), a versatile method that is capable of monitoring the ultrafast dynamics of rapid dissociation in the gas phase after the removal of an electron. The method uses a technique called pump-probe, which makes use of two time-delayed laser pulses. In this work, the …


Synthesis Of Supported Metal Nanoparticles On High Surface Area Supports For Application In Energy Conversion And Heterogeneous Catalysis, Nazgol Norouzi Jan 2020

Synthesis Of Supported Metal Nanoparticles On High Surface Area Supports For Application In Energy Conversion And Heterogeneous Catalysis, Nazgol Norouzi

Theses and Dissertations

Precise control of metal nanoparticles’ size, composition, and dispersity over high surface area supports are highly desirable to address current challenges in energy storage and conversion as well as catalytic processes involving precious metals. Therefore, developing viable synthetic routes that enable new catalytic systems derived from inexpensive transition metals or limited use of precious metals is vital for clean energy applications such as fuel cells and rechargeable batteries or affordable drugs in the pharmaceuticals arena. In addition to metal components of heterogeneous catalysts, the catalyst support is an integral part of catalyst design as it can impart both physical stability …


Open Ensemble Modeling Of Confined Electrolytes, Serban Zamfir Jan 2020

Open Ensemble Modeling Of Confined Electrolytes, Serban Zamfir

Theses and Dissertations

The main purpose of my study was to work towards better understanding the behavior of salt solutions in nanoconfinements and its causes. To this end I have developed an in-house C++ code that can perform notoriously challenging open ensemble Monte Carlo molecular simulations, calculate relevant thermodynamic and extract structural information about each system. I use this code in my first project which deals with the intrusion/extrusion of aqueous NaCl into a nanopore open to a pressurized bulk environment. For my second project, I study the effect of explicitly accounting for intramolecular polarization and accompanying multi-body interactions on the uptake, structure, …


Mechanistic Study Of C-H Activation By Iridium Complexes, Rozalie S G Corea Jan 2020

Mechanistic Study Of C-H Activation By Iridium Complexes, Rozalie S G Corea

Theses and Dissertations

C-H activation is considered the “holy grail” of chemistry. Remote, selective C-H activation has many applications such as modifying precursors, adding complexity to molecules, and modifying pre- existing structures in a reduced number of steps. Previous work by Swift and Gronert identified an iridium(III) phenanthroline complex that can activate C-H bonds of cyclohexane. The objective of this dissertation is to study the mechanism and regioselectivity of this complex in common precursors, namely 1-butanol, 1-methoxybutane and butyl acetate.

The studies were carried out in the gas phase on a modified mass spectrometer. Selectively deuterated alcohol, ether and ester were used to …


Investigations Of Graphene-Supported Single-Atom Catalyst Model Ions In The Gas Phase, Michael Borrome Jan 2020

Investigations Of Graphene-Supported Single-Atom Catalyst Model Ions In The Gas Phase, Michael Borrome

Theses and Dissertations

Recent developments in heterogeneous catalysis has led to the conception of single-atom catalysts (SACs), a class of catalysts based on isolated metal atoms anchored to a support scaffold. SACs are often much more reactive and can offer better selectivity when compared to nano-scale catalysts. In order to realize the full potential of SACs, a sound understanding of the underlying catalytic mechanisms is required. However, surface analysis tools can become less effective in studying catalytic mechanisms at the atomic scale. Mass spectrometry has proven to be a robust technique for studying organometallic catalytic mechanisms at the single-molecule level. Using mass spectrometry, …