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Full-Text Articles in Physical Sciences and Mathematics

Rational Design Of Multifunctional Nanocatalysts For Environmental Remediation And Energy Conversion Technologies, Md Ariful Ahsan Dec 2021

Rational Design Of Multifunctional Nanocatalysts For Environmental Remediation And Energy Conversion Technologies, Md Ariful Ahsan

Open Access Theses & Dissertations

The discovery of efficient and sustainable carbon-based nanotechnologies to solve both the scarcity of drinking water and global energy crisis has become a paramount task in the last decades. Owed to the fast population growth and industrialization of the modern society, access to potable water and clean energy technologies is becoming very hard around the globe. Water pollutants have become a serious threat to the environment and ecology because of their toxic nature. Parallelly, the current hydrocarbon-based fuel industries are generating high levels of contamination across the planet, making imperative the development of cleaner energy technologies. In this regard, the …


Synthesis, Characterization, And Direct-Ink-Writing Of Syntactic Foams, Andrea Irigoyen Dec 2021

Synthesis, Characterization, And Direct-Ink-Writing Of Syntactic Foams, Andrea Irigoyen

Open Access Theses & Dissertations

This project encompasses three different methods to fabricate syntactic foams using a PDMS matrix i.e., hollow spheres inclusion, pore generator leaching by solvent, and emulsion. The foam formation by using polysiloxane hollow spheres is done in a 3-step process. The first step is to create a core of polystyrene following a dispersion polymerization process. The goal for the size of the pore is to monodisperse and have an average diameter of 5-10 μm, so the polystyrene core must be as well within that range. After that, the cores are coated with a polysiloxane shell by following a polymerization by condensation …


Combination Of Nir Triggered Lanthanide Upconverting Nanoplatforms With Fullerene For Controlled Drug Release And Photo Cancer Therapy, Lei Ma Dec 2021

Combination Of Nir Triggered Lanthanide Upconverting Nanoplatforms With Fullerene For Controlled Drug Release And Photo Cancer Therapy, Lei Ma

Open Access Theses & Dissertations

Photodynamic therapy (PDT) is an emerging, externally activatable, treatment modality for various diseases, especially for cancer therapy. Similar to radiotherapy, the mode of action with PDT involves the use of electromagnetic radiation to generate radical species in situ. However, PDT is a much milder approach for cancer treatment. Because of the unique physicochemical properties of fullerenes (such as C60), many potential biomedical applications, including PDT, became possible with them. As a main principle of PDT, the anticancer properties of various fullerene preparations usually result from their ability to generate cytotoxic reactive oxygen species (ROS), after photoexcitation. However, because of the …


8th Position Bodipy Chemistry, Laura I. Saucedo Dec 2021

8th Position Bodipy Chemistry, Laura I. Saucedo

Open Access Theses & Dissertations

The projects examined in this dissertation demonstrate how the meso substituents N and S lone pair-BODIPY core interaction influence the chemistry and properties of BODIPY fluorophores. Three objectives were completed experimentally and computationally. In the first project the meso amide substituent delocalizes the nitrogen lone pair into the carbonyl, preventing a hemicyanine resonance that causes blue emission in 8-amino-BODIPYs. The second and third projects substituting aniline or phenylthiol derivatives onto the 8th position, respectively. The aniline and phenylthio lone pair interaction with the BODIPY core can be modulated by electron-donating (ED) or –withdrawing (EW) moieties placed para on the aryl …


Synthesis Of Fullerene Derivatives For Diverse Applications: From Catalysis To Photovoltaics, Olivia Fernandez-Delgado Aug 2021

Synthesis Of Fullerene Derivatives For Diverse Applications: From Catalysis To Photovoltaics, Olivia Fernandez-Delgado

Open Access Theses & Dissertations

AbstractFullerene functionalization has enabled the improvement in their solubility, optoelectronic, semiconductive, chemical and physical properties that allow their use in several fields such as photovoltaics, catalysis and for biological applications. Their good electron transporting properties have been widely studied in perovskite solar cell (PSC) devices and more recently, there have been more articles focused specifically on the molecular interactions of the fullerene functional groups with the perovskite layer which has allowed to obtain high power conversion efficiencies (PCE) of 25.5%. On the other hand, fullerenes are beginning to be studied as molecular catalysts for water splitting electrocatalytic processes, resulting in …


Magnesiothermic Combustion Synthesis Of Nanocrystalline Silicon And Oxidation Kinetics Of Magnesium Particles, Sergio Cordova Aug 2021

Magnesiothermic Combustion Synthesis Of Nanocrystalline Silicon And Oxidation Kinetics Of Magnesium Particles, Sergio Cordova

Open Access Theses & Dissertations

Magnesium (Mg) is a well-known reduction agent in metallurgy (more specifically, in metallothermy). Recently, magnesiothermic reduction of oxides has been used in self-propagating high-temperature synThesis (SHS) of advanced materials such as ultrahigh-temperature ceramics (UHTC). The magnesiothermic SHS has also been used for the conversion of silica (SiO2) to silicon-based materials for thermoelectric applications. However, since oxidation of Mg releases a lot of heat, the direct use of it as the reduction agent leads to excessively high temperatures and undesirable sintering of the products. We have proposed to use magnesium silicide (Mg2Si) instead of Mg in the SHS of nanostructured silicon. …


Synthesis And Study Of F-Block Complexes Containing Metal-Arene Interactions, Jesse Murillo Aug 2021

Synthesis And Study Of F-Block Complexes Containing Metal-Arene Interactions, Jesse Murillo

Open Access Theses & Dissertations

The f-block elements are of great interest due to the under explored nature of their chemical bonding interactions and their unique magnetic and electronic properties. For the 5f-orbital elements, such as uranium, the f-orbitals are more readily available for bonding than the contracted, core like, 4f-orbitals of the lanthanides. This makes uranium complexes informative probes into the nature of f-(p/d/f) bonding interactions. Recently, it has been shown that a growing subset of complexes possessing supported uranium-arene interactions have the capability to stabilize unusually low valent U(II) molecular species and support novel catalytic activity. In our laboratory, we have begun to …


Computational Investigation Of Nanoparticle Immersion And Selfassembly, Tara Allison Tyler Nitka Aug 2021

Computational Investigation Of Nanoparticle Immersion And Selfassembly, Tara Allison Tyler Nitka

Open Access Theses & Dissertations

Both neutral and charged nanoparticles with a variety of compositions, shapes, and sizes have beenpreviously prepared. These nanoparticles have been demonstrated to self-assemble into a variety of superlattices and binary superlattices both in bulk solution and at surfaces of solutions, and the structures formed by self-assembly have been shown to depend on nanoparticle chemistry and charge as well as on whether assembly takes place at a surface or in bulk. Furthermore, the prepared isolated and self-assembled nanoparticles have a number of biomedical, nanotechnology, and industrial applications. In this Dissertation, I present my research on three general topics. First, I will …


Molecular Dynamics Of Nucleic Acids, Proteins, And Their Complexes: From Atomistic And Coarse-Grained Descriptions To New Methodologies, Parth Chaturvedi Aug 2021

Molecular Dynamics Of Nucleic Acids, Proteins, And Their Complexes: From Atomistic And Coarse-Grained Descriptions To New Methodologies, Parth Chaturvedi

Open Access Theses & Dissertations

Computational modeling of biological macromolecules through molecular dynamics (MD) simulations is becoming increasingly useful to interpret the experimental results and guide the future experiments. Over the last decade, MD simulations have become much more powerful and accessible due to advancements in fields of structural biology, computer science and integrated chip design. In this Thesis, I utilize different MD simulation techniques to model interaction of and antiviral mechanisms. Within the framework of nucleic acid modelling, we describe first dynamics of small circular single stranded nucleic acids and highlight key dynamical differences of backbone behavior in solution between DNA and RNA and …


Organic Synthesis For Solving Clinical Conundrums Of Drug Activation And For Facilitating Natural Product Drug Discovery, Elkin Libardo Romero May 2021

Organic Synthesis For Solving Clinical Conundrums Of Drug Activation And For Facilitating Natural Product Drug Discovery, Elkin Libardo Romero

Open Access Theses & Dissertations

Organic chemistry is an exploratory world in which chemists translate their knowledge by creating new molecules and explore their biological and physical properties. For the past three years, our research has been focused on organic synThesis and chemical biology to solve challenges in this area. Two major approaches have been faced: First, the chemical synThesis of the active metabolite of antithrombotic prodrug Plavix (clopidogrel). Clopidogrel (CPG) has been widely used as an antithrombotic prodrug, which undergoes extensive metabolism in patients; among it, only a trivial portion is converted through a series of cytochrome P450 (CYP)-catalyzed thiophene degradation to form active …


Novel N-Derivatized-7-Nitroindolines For The Synthesis Of Photocleavable Crosslinkers, And For Solid Phase Peptide Synthesis, Hector Patricio Del Castillo May 2021

Novel N-Derivatized-7-Nitroindolines For The Synthesis Of Photocleavable Crosslinkers, And For Solid Phase Peptide Synthesis, Hector Patricio Del Castillo

Open Access Theses & Dissertations

7-Nitroindoline-based photochemistry has focused mostly on N-acyl-7-nitroindolines, which have been used as photocleavable protecting groups for carboxylic acids that can be efficiently removed by illumination with UV-light. They offer an alternative to the more commonly used o-nitrobenzyl-based photocleavable protecting groups. N-acyl-7-nitroindolines can also be used as photochemical acylating agents in inert solvents. For example, they have found application in peptide fragment condensation, the convergent synThesis of N-glycopeptides, and the synThesis of peptide thioesters, forming amide and thioester bonds with amine and thiol nucleophiles, respectively, under neutral conditions. The photochemical activation of N-acyl-7-nitroindolines can occur with UV light (λ = 350 …


Synthesis And Characterization Of Functiona Materials For 3d Printed Composites, Elizabeth Irene Reza May 2021

Synthesis And Characterization Of Functiona Materials For 3d Printed Composites, Elizabeth Irene Reza

Open Access Theses & Dissertations

The following body of work encompasses the synThesis, upscaling, additive manufacturing, and characterization of microspheres as functional fillers incorporated into polymer syntactic foams. Synthesizing microspheres permits control over morphology, dispersion of particles, and size while the use of direct write manufacturing allowed for the controllability of filler orientation. Two different syntactic foams were developed from similar methodologies: (1) a silicone syntactic foam (2) epoxy syntactic foam. The silicone epoxy foam showed an increasing in damping and elastic modulus. The epoxy syntactic foams showed an enhanced thermal and electrical properties.