Physical Sciences and Mathematics Commons^™

Ultrasound-Driven Fabrication Of Nanosized High-Entropy Materials For Heterogeneous Catalysis, Francis Uchenna Okejiri

Doctoral Dissertations

High-entropy materials (HEMs) have emerged as a new class of multi-principal-element materials with great technological prospects. As a unique class of concentrated solid-solution materials, HEMs, formed on the premise of incorporating five or more principal elements into a single crystalline phase, provide an excellent opportunity to access superior catalytic materials ‘hiding’ in the unexplored central regions of a multicomponent phase space of higher orders.

However, the fabrication of HEMs is energy-intensive, typically requiring extreme temperatures and/or pressures under which agglomeration of particles occurs with a commensurate decrease in surface area. For most catalytic applications, non-agglomerated particles with high surface areas …

Investigating The Accumulation, Sub-Organ Distribution, And Biochemical Effects Of Nanomaterials Using Mass Spectrometry, Kristen Nicole Sikora

Doctoral Dissertations

Gold nanoparticles (AuNPs) are attractive materials for use in various biomedical applications, such as therapeutic delivery, due to their unique chemical properties and modular tunability. Mass spectrometry methods, including laser desorption/ionization mass spectrometry (LDI-MS) and inductively coupled plasma mass spectrometry (ICP-MS) have been successfully used to evaluate the distribution of AuNPs in complex biological systems. As new AuNP-based materials are developed for applications in therapeutic delivery, it is essential to simultaneously develop analytical techniques that can comprehensively assess their behavior in vivo. In this dissertation, novel mass spectrometric methods have been developed and utilized to evaluate the uptake, distribution, …

Chemical Manipulation Of Macrophages: Nanomaterial And Molecular Approaches, Joseph Hardie

Doctoral Dissertations

Macrophages, phagocytic cells of the innate immune system, are the body’s first line of defense against pathogens and are responsible for tissue maintenance. Macrophages are capable of sensing and internalizing external stimuli, and in response change their morphology and phenotype accordingly. Because macrophages are integral to immune function and tissue maintenance, dysregulation of macrophage behavior is associated with a range of diseases including infections, cancer, autoimmune disorders, atherosclerosis, and more. Because of the implications of macrophage failure, there is interest in creating new materials to manipulate macrophage behavior for a therapeutic effect. In this thesis, I describe the application of …

Powering Advances In Next-Generation Photovoltaics Through Materials Synthesis And Characterization, Christie L.C. Ellis

Doctoral Dissertations

Solar energy is our most abundant natural resource: the energy from sunlight that strikes the Earth in one hour is more than the energy consumed globally in a year. This makes photovoltaics, which convert solar energy into electrical energy, a critical technology to pursue. 95% of the photovoltaic market is dominated by silicon; its high efficiency, stability, and plummeting manufacturing costs made it the clear choice for commercialization. However, silicon solar cells are thick, heavy, opaque, and rigid, limiting potential applications. They are energy- and resource-intensive to produce, and their manufacturing process uses and produces several toxic substances. “Next-generation” photovoltaic …

Inkjet Printing For Biosensing And Security Applications, Brian Creran

Doctoral Dissertations

The adaptation of inkjet printing technology has recently been used to create controlled high throughput micro- and nano-scaled structures. Coupling this technique with gold nanoparticles in our research has produced new platforms for biosensors, chemical patterning, and anti-counterfeiting applications. In this presentation, we will highlight promising fabrication strategies including the development of test strips for the determination of bacteria in drinking water as well as the use of patterned nanoparticles for security applications.

Mass Spectrometric Characterization And Imaging Of Nanoparticles In Biological Samples, Bo Yan

Doctoral Dissertations

Nanoparticles (NPs) are being investigated widely for use in biomedical applications such as imaging, drug delivery, and cancer therapy due to their small size and readily tunable properties. The ability to accurately characterize NPs and monitor their spatial distributions is highly desirable for effective use of NPs and evaluation of their potential adverse environmental, health, and safety effects. In this dissertation, a simple, fast, and sensitive method based on laser desorption/ionization mass spectrometry (LDI-MS) to characterize and track NPs in biological systems has been developed. This method is especially well suited for characterizing core-shell structured NPs, such as quantum dots …