Engineering Commons^™

Application Of Immobilized Palladium Monolithic Catalysts In Suzuki-Miyaura And Tsuji-Wacker Redox Reactions, Sajjad Ghobadi

Theses and Dissertations

Herein, a wholistic analysis of the viability of monolithic catalysts for redox reactions is presented. The interdisciplinary approach taken in this systematic study included preparation and investigation on Pd-on-carbon monoliths as catalysts in a flow and electrochemical settings.

The Suzuki-Miyaura reaction-focused study led to rational design, preparation, and successful application of Pd⁰-on-graphene oxide (GO) monolithic catalysts in flow conditions. In this study a combination of chemical reduction, freeze-casting, and vapor-phase reduction processes was applied to Pd-GO structures leading to the preparation of these monoliths. The Suzuki flow synthesis reactions revealed that the monolithic structure led to significantly improved …

Beneficiation Of Coal Using Supercritical Water And Carbon Dioxide Extraction, Matthew Decuir Virginia Commonwealth University Cl

Theses and Dissertations

This work explores the use of carbon dioxide, water, and their mixtures as solvent for the pre-combustion beneficiation of raw coal without using any toxic mineral acids in the temperature range of 200-400℃. The fluid polarity, ionic constant, and supercritical point can be adjusted by H₂O/CO₂ ratio and temperature. Adding carbon dioxide to hydrothermal fluid also increases the ionization by forming carbonic acid. Extractions with supercritical fluids have several benefits including enhanced mass transport, ease of separation and recycle, wide range of extractive capability and tunability, better inherent safety, and in the case of carbon dioxide and …

Self-Assembled Metal Nanoparticle/Polymer Nanocomposites As Nanoreactors For One-Pot Reactions, Andrew Harrison

Theses and Dissertations

Polymer nanoreactors incorporating gold nanoparticle catalysts were self-assembled via Flash Nanoprecipitation. The incorporated gold nanoparticles maintained catalytic activity, which was evaluated using reduction of 4-nitrophenol with sodium borohydride as a model reaction. The diffusion coefficient for 4-nitrophenol was determined by NMR and used to calculate the second Damköhler number, which indicated that the systems were not diffusion limited. Despite similar diffusion coefficients, catalytic performance was strongly affected by the co-precipitant. For example, the apparent reaction rate per surface area using castor oil was over 8-fold greater than polystyrene. Thus, we measured the partition coefficient of 4-nitrophenol between water and castor …

Higher Tensile Forces Across Cellular Junctions And An Intact Nuclear Linc Complex Is Required For Epithelial Function And Stability, Fnu Vani Narayanan

Theses and Dissertations

Recent advances in three-dimensional (3D) cell culture systems have provided key insights into the understanding of biochemical and physiological states of native tissue. A significant progress in the field of mechanobiology involves measuring cellular traction forces in a more native 3D environment. However, the effects of mechanical forces exerted across cellular junctions and the nuclear LINC complex, in an organized 3D system has not been investigated thus far. Epithelial cells spontaneously form acini (also known as cysts or spheroids) with a single, fluid-filled central lumen, when grown in 3D matrices. The size of the lumen is dependent on apical secretion …

Formulation And Validation Of Nanoparticle Controlled Delivery For Chemotherapeutic Drug Products, Shani L. Levit

Theses and Dissertations

Taxol, a formulation of paclitaxel (PTX), is one of the most widely used anticancer drugs, particularly for treating recurring ovarian carcinomas following surgery. Clinically, PTX is used in combination with other drugs such as lapatinib (LAP) to increase treatment efficacy. Delivering drug combinations with nanoparticles has the potential to improve chemotherapy outcomes. In this study, we use Flash NanoPrecipitation, a rapid, scalable process to encapsulate weakly hydrophobic drugs (logP in vitro. Encapsulating either PTX or LAP into nanoparticles increases drug potency. When PTX and LAP are co-loaded in the same nanoparticle, they have a synergistic effect that is greater than …

Reaction Profiling Of Extracellular Protein Phosphorylation Through A Microfluidic Reactor Coupled With Raman Spectroscopy, Abigail Casey

Theses and Dissertations

Diseases and disorders in the human body are considered abnormalities of proper cellular function. Understanding the signal transduction mechanisms that cause these abnormalities is crucial to developing earlier detection methods, better treatment options and effective cures. While current diagnostic procedures are powerful tools in diagnosing diseases, they are ineffective in informing physicians on the real-time behavior of the signal transduction mechanisms associated with diseases and disorders. Currently, disease progression is monitored over time through routine patient visits and testing by one or more of the above techniques. By developing an approach that can monitor structural and conformational changes of proteins …