Chemistry Commons^™

Aggregation And Coagulation Of C60 Fullerene As Affected By Natural Organic Matter And Ionic Strength, Hamid Mashayekhi

Doctoral Dissertations

With widespread production and use of C₆₀ fullerene nanoparticles, their release to the environment and natural waters is inevitable. The colloidal nature of C₆₀ fullerene in the aquatic environment significantly influences its behavior in the environment including its transport, bioavailability and toxicity to different organisms. Natural organic matter (NOM) is a ubiquitous and reactive material in aquatic environments with significant structural heterogeneity. Therefore, the effect of NOM molecules on the colloidal behavior of fullerene particles needs to be studied. A major part of NOM consists of humic acids (HA). HAs have pronounced effects on the aggregation of C …

Development Of Dihydrochalcone Functionalized Gold Nanoparticles For Augmented Antineoplastic Activity, Jason N. Payne

Masters Theses & Specialist Projects

Phloridzin, an antidiabetic and antineoplastic agent usually found in fruit trees, is a dihydrochalcone constituent that has a clinical/pharmaceutical significance as a sodiumglucose linked transport 2 (SGLT2) inhibitor. Phloridzin never experienced widespread clinical usage in the pharmaceutical market due to its side effects and poor bioavailability when compared to other antidiabetic therapeutics. The poor bioavailability is primarily attributed to the degradation of the glycosidic bond of the phloridzin, resulting in the formation of phloretin, the aglycone of phloridzin and glucose. While phloretin displays a reduced capacity of SGLT2 inhibition, this nutraceutical shows enhanced antineoplastic activity in comparison to phloridzin. Gold …

Development Of New Radiolabeling Methods And Insights On Ionizing Radiation Interactions With Nanoparticles, Travis Shaffer

Dissertations, Theses, and Capstone Projects

Nanoparticles are often combined with radionuclides for various applications, ranging from waste remediation to imaging and therapy in the medical field. The overarching aim of this body of work is two-fold. The first aim is development of new radiolabeling methods for various nanoparticles that allow stable attachment of a variety of imaging and therapeutic radionuclides. The second portion more fully describes mechanisms of interaction between ionizing radiation and nanoparticles.

The following advancements will be presented in this dissertation: i) a new radiolabeling method for silica and silica-based nanoparticles that does not require the use of specific chelators, with both radiochemical …

Expanding The Applicability Of Raman Spectroscopy For Monitoring Photocatalytic Degradation, Franklyn Wallace

Mahurin Honors College Capstone Experience/Thesis Projects

Compared to other types of wastewater pollutants, dangerous chemical compounds such as pharmaceuticals, pesticides, and herbicides are difficult to remove and consequently being detected (at least in part because detection limits have decreased) in drinking water at increasing concentrations. Photocatalytic degradation degrades harmful compounds to innocuous end products using energy from light. Although it is effective and cost-efficient, the underlying chemical mechanisms are not understood well enough to ensure that dangerous intermediate products are not formed during the degradation process. Raman spectroscopy can be used to analyze photocatalytic degradation reactions in real time, identifying intermediate products based on spectral features. …

Assembly Of Nucleic Acid-Based Nanoparticles By Gas-Liquid Segmented Flow Microfluidics, Matthew L. Capek, Ross Verheul, David H. Thompson

The Summer Undergraduate Research Fellowship (SURF) Symposium

The development of novel and efficient mixing methods is important for optimizing the efficiency of many biological and chemical processes. Tuning the physical and performance properties of nucleic acid-based nanoparticles is one such example known to be strongly affected by mixing efficiency. The characteristics of DNA nanoparticles (such as size, polydispersity, ζ-potential, and gel shift) are important to ensure their therapeutic potency, and new methods to optimize these characteristics are of significant importance to achieve the highest efficacy. In the present study, a simple segmented flow microfluidics system has been developed to augment mixing of pDNA/bPEI nanoparticles. This DNA and …

Recent Progresses In Molybdenum-Based Electrocatalysts For The Hydrogen Evolution Reaction, Ze-Xing Wu, Jie Wang, Jun-Po Guo, Jing Zhu, De-Li Wang

Journal of Electrochemistry

Electrochemical catalytic production of hydrogen has been considered as a promising and sustainable strategy for clean and renewable energy technologies. Molybdenum-based non noble metal catalysts for the hydrogen evolution reaction have attracted extensive attention due to its effective catalytic performance. In this review, the recent progresses in molybdenum-carbide, phosphide, nitride and sulfide electrocatalysts are presented. In addition, the strategies to improve the catalytic performance are analyzed and the prospects for the future development trends are expected.

A 1-D Coordination Polymer Route To Catalytically Active Co@C Nanoparticles, Anand Pariyar, Siddharth Gopalakrishnan, Joseph Stansbery, Rajankumar L. Patel, Xinhua Liang, Nikolay Nikolaevich Gerasimchuk, Amitava Choudhury

Chemistry Faculty Research & Creative Works

Pyrolysis of a 1-D polymeric cobalt(ii) coordination complex ([Co(BDC)(Mim)₂]_n, H₂BDC = benzenedicarboxylic acid; Mim = N-methylimidazole) results in the formation of carbon embedded fcc cobalt nanoparticle composites, Co@C. The as-prepared Co@C shows an agglomerated secondary structure with a highly embedded carbon shell comprising of cobalt nanoparticles of 20-100 nm. These Co@C particles show excellent catalytic activity in the reduction of nitrophenol to aminophenol, studied as a model reaction, and evolves as a promising candidate for the gas phase reduction process.

Poly(Ester Amide)S With Pendant Azobenzenes: Multi-Responsive Self-Immolative Moieties For Modulating Polymer Assemblies, Andrew D. Wong, Alex Prinzen, Elizabeth Gillies

Chemistry Publications

Azobenzenes are well-known for their trans–cis photoisomerization, but it was recently demonstrated that azobenzene derivatives could also undergo reduction to trigger a 1,6-elimination and initiate de- polymerization of a self-immolative polymer. Herein we explore the optimization of azobenzenes as reduction-sensitive moieties, and their incorporation into functional materials. A library of azobenzenes with electron-withdrawing groups was synthesized, and their rates of reduction by hydrazine were deter- mined. Unexpectedly, a 2-Cl substituent increased the rate of reduction more than other electronegative or sterically-demanding substituents. Next, a new diester monomer containing the 2-Cl-azobenzene was synthesized and incorporated into a poly(ester amide) (PEA) backbone, …

Restricted Mobility Of Specific Functional Groups Reduces Anti-Cancer Drug Activity In Healthy Cells, Murillo L. Martins, Rosanna Ignazzi, Juergen Eckert, Benjamin Watts, Ramon Kaneno, Willian F Zambuzzi, Luke Daemen, Margarida J Saeki, Heloisa N Bordallo

Chemistry Faculty Publications

The most common cancer treatments currently available are radio- and chemo-therapy. These therapies have, however, drawbacks, such as, the reduction in quality of life and the low efficiency of radiotherapy in cases of multiple metastases. To lessen these effects, we have encapsulated an anti-cancer drug into a biocompatible matrix. In-vitro assays indicate that this bio-nanocomposite is able to interact and cause morphological changes in cancer cells. Meanwhile, no alterations were observed in monocytes and fibroblasts, indicating that this system might carry the drug in living organisms with reduced clearance rate and toxicity. X-rays and neutrons were used to investigate the …

Development And Application Of New Solid-State Models For Low-Energy Vibrations, Lattice Defects, Entropies Of Mixing, And Magnetic Properties, Jacob M. Schliesser

Theses and Dissertations

Low-temperature heat capacity data contain information on the physical properties of materials, and new models continue to be developed to aid in the analysis and interpretation of heat capacity data into physically meaningful properties. This work presents the development of two such models and their application to real material systems. Equations describing low-energy vibrational modes with a gap in the density of states (DOS) have been derived and tested on several material systems with known gaps in the DOS, and the origins of such gaps in the DOS are presented. Lattice vacancies have been shown to produce a two-level system …

Multi-Frequency Ferromagnetic Resonance Investigation Of Nickel Nanocubes Encapsulated In Diamagnetic Magnesium Oxide Matrix, Saritha Nellutla, Sudhakar Nori, Srinivasa R. Singamaneni, John T. Prater, Jagdish Narayan, Alix I. Smirnov

Chemical Sciences Faculty Publications

Partially aligned nickel nanocubes were grown epitaxially in a diamagnetic magnesium oxide (MgO:Ni) host and studied by a continuous wave ferromagnetic resonance (FMR) spectroscopy at the X-band (9.5 GHz) from ca. 117 to 458 K and then at room temperature for multiple external magnetic fields/resonant frequencies from 9.5 to 330 GHz. In contrast to conventional magnetic susceptibility studies that provided data on the bulk magnetization, the FMR spectra revealed the presence of three different types of magnetic Ni nanocubes in the sample. Specifically, three different ferromagnetic resonances were observed in the X-band spectra: a line 1 assigned to large nickel …

Tracking Silver, Gold, And Titanium Dioxide Nanoparticles Through Drinking Water Systems By Single Particle - Inductively Coupled Plasma - Mass Spectrometry, Ariel Renee Donovan

Masters Theses

"Single particle (SP)-ICP-MS methods were developed to characterize and quantify Ti-containing, titanium dioxide, silver, and gold NP concentration, size, size distribution and dissolved metal element concentration in surface water and treated drinking water. The effectiveness of conventional drinking water treatments (including lime softening, alum coagulation, filtration, and disinfection) to remove NPs from surface water was evaluated using six-gang stirrer jar test simulations. Six-gang stirrers were used to simulate drinking water treatments including lime softening, alum coagulation, powdered activated carbon sorption, filtration, and disinfection by free chlorine. Lime softening effectively removed most nanoparticles added. Source and drinking waters from three large …

Development Of Protein-Polymer Core-Shell Nanoparticles (Ppcs-Nps) As Efficient Vehicles To Deliver Therapeutic Agents Across Blood Brain Barrier (Bbb), Napat Tandikul

Theses and Dissertations

Blood Brain Barrier (BBB) plays a main role as selective barrier which controls and limits access of chemicals, molecules and therapeutic agents from blood to brain. The BBB endothelial cells are connected by Tight Junctions (TJs) which close intracellular spaces between the endothelial cells and block the free diffusion of substances, therefore many potential drugs for treating human brain diseases cannot reach the brain in sufficient concentration. Recently, many studies have thrown an interest in development of nanoparticles for delivering drugs and imaging agents across BBB. Our research group has developed protein-polymer core-shell nanoparticles (PPCS-NPs) which demonstrate great potential for …

Studies Of The Properties Of Designed Nanoparticles Using Atomic Force Microscopy, Steve Matthew Deese

LSU Doctoral Dissertations

The purpose of the research in this dissertation was to elucidate the intrinsic properties of how nanoparticles are different from bulk materials. This was done by mechanical and electronic studies of the properties of designed nanoparticles using advanced modes of atomic force microscopy. Information relating to the work functions, contact potential difference, Young’s Moduli, elasticity, and viscoelasticity can be investigated using state-of-the-art atomic force microscope (AFM) experiments. Subsurface imaging of polystyrene encapsulated cobalt nanoparticles was achieved for the first time using Force Modulation Microscopy (FMM) in conjunction with contact mode AFM. Previously prepared sample of polystyrene coated cobalt nanoparticles were …