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Full-Text Articles in Physical Sciences and Mathematics

Flexible Tethers In Multi-Chromophoric Systems: Linking Photophysics With Assembly, Jeffrey M. Lucas Nov 2014

Flexible Tethers In Multi-Chromophoric Systems: Linking Photophysics With Assembly, Jeffrey M. Lucas

Doctoral Dissertations

Aggregation and folding events in conjugated polymers have a dramatic effect on the photophysics, and in turn, the efficiency of said species in organic electronic devices. The factors that lead to twisting, bending and folding in conjugated polymers have been studied in numerous polymeric materials, but due to the variability of these events, they remain poorly understood. To probe the spectroscopic signatures of folding and to link them with conformational and morphological features formed by these species in the solid state, a series of alternating co-polymers were then synthesized, incorporating the 2- and 4-carbon tethers with oligo-phenylenevinylene derivatives. Static absorption, …


Engineering Surface Functionality Of Nanoparticles For Biological Applications, Yi-Cheun Yeh Nov 2014

Engineering Surface Functionality Of Nanoparticles For Biological Applications, Yi-Cheun Yeh

Doctoral Dissertations

Engineering the surface functionality of nanomaterials is the key to investigate the interactions between nanomaterials and biomolecules for potent biological applications such as therapy, imaging and diagnostics. My research has been orientted to engineer both of the surface monolayers and core materials to fabricate surface-functionalized nanomaterials through the synergistic multidisciplinary approach that combine organic chemistry, materials science and biology. This thesis illustrates the design and synthesis of the surface-funcitonalized quantum dots (QDs) and gold nanoparticles (AuNPs) for the fundamental studies and practical applications. For QDs, A new class of cationic QDs with quaternary ammonium derivatives was synthesized to provide permanent …


The Discovery And Study Of Fluvirucin B1 Polyketide Synthase, Tsung-Yi Lin Nov 2014

The Discovery And Study Of Fluvirucin B1 Polyketide Synthase, Tsung-Yi Lin

Doctoral Dissertations

Rapidly decreasing numbers of viable therapeutic leads in the pharmaceutical pipeline demand new, sustainable methods for improved drug discovery and development. Despite vast improvements in de novo drug design and target recognition, Nature remains the richest source of small molecule therapeutics. Among many natural products, polyketides are not only the most promising ones for developing new antibiotic leads, but also exhibit unusually high therapeutic value ranging from clinical use as anticancer, antiviral, and immunosuppressant drugs. Modular polyketide synthases (PKSs) are dedicated nano-machinery that can be manipulated to produce a structurally diverse library for drug discovery programs. The ability to manipulate …


Understanding Structure-Property Relationships At The Nano-Bio Interface For Delivery Applications, Krishnendu Saha Nov 2014

Understanding Structure-Property Relationships At The Nano-Bio Interface For Delivery Applications, Krishnendu Saha

Doctoral Dissertations

The surface chemistry of the nanomaterials creates an effective interface between two entirely different worlds: nanotechnology and biology. Understanding the interaction between nanomaterial surface chemistry and biological entities can be useful for a wide variety of biomedical applications as well as can provide crucial information for nanotoxicology. In my research, I have used gold nanoparticles as a model platform to synthesize a family of nanoparticles with atomic level control of their surface properties and probe their interaction with biological systems. First part of my research focused on the understanding the uptake mechanisms, toxicity, and hemolytic properties of cationic nanoparticles, an …


Nanoparticle Building Blocks For Functional Structures, Youngdo Jeong Nov 2014

Nanoparticle Building Blocks For Functional Structures, Youngdo Jeong

Doctoral Dissertations

A major goal in material science is achieving a desired function using structures fabricated with designed building blocks. Advanced synthetic and self-assembly techniques allow various nanomaterials to become promising building blocks, providing the control of the interaction between building blocks. The unique properties of nanomaterials can be transferred to structured systems. Among nanomaterials, inorganic nanoparticles such as gold nanoparticles (AuNPs), magnetic particles, and quantum dots (QDs) provide useful physical properties stemming from their inorganic core, large surface areas, and oriented surface functionalities. My research has focused on fabricating functional systems using gold nanoparticles (AuNPs), manipulating the interaction between AuNPs, bio-entities, …


Mass Spectrometric Characterization And Imaging Of Nanoparticles In Biological Samples, Bo Yan Aug 2014

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 …


Molecular Engineering Strategies For The Design And Synthesis Of New Organic Photovoltaic Materials, Paul J. Homnick Aug 2014

Molecular Engineering Strategies For The Design And Synthesis Of New Organic Photovoltaic Materials, Paul J. Homnick

Doctoral Dissertations

Dramatic improvements in organic photovoltaic device efficiency can be obtained by optimizing spectral absorbance and frontier molecular orbital (FMO) energies, increasing solid state exciton/charge mobility, and utilizing p-/n-type nanoarchitecture. Combining all of these properties into a new material presents a considerable synthetic challenge because potential commercial applications require materials that are high-performance and inexpensive. Thus, it is advantageous to design new materials using a versatile, modular synthetic approach that allows each design criterion to be engineered individually, in a synthetically efficient manner. Several strategies were successfully pursued using simple interchangeable electron donor and acceptor components as functional modules, which …


Developing Spatial Reasoning Skills In General Chemistry Students, Deborah L. Carlisle Aug 2014

Developing Spatial Reasoning Skills In General Chemistry Students, Deborah L. Carlisle

Doctoral Dissertations

The study of organic chemistry requires the understanding and use of spatial relationships, which can be challenging for many students. Prior research has shown that there is a need to develop students’ spatial reasoning skills. To that end, this study implemented guided activities designed to strengthen students’ spatial skills, with the aim of preparing students for organic chemistry and other future STEM courses. Students, taking the second semester of a two-semester general chemistry course, engaged in these activities. This study followed a quasi experimental design, in which the experimental (n = 209) and the control group (n = 212) were …


Ligand-Receptor Interactions For Supramolecular Disassembly With Applications In Screening And Drug Delivery, Diego Amado Torres Aug 2014

Ligand-Receptor Interactions For Supramolecular Disassembly With Applications In Screening And Drug Delivery, Diego Amado Torres

Doctoral Dissertations

Proteins have the capacity to bind specific sets of compounds known as ligands, these are small molecules with a recurrent theme in their molecular design that is a characteristic exploited here to (i) identify particular affinities of small molecules for proteins with the aim of using them as ligands, inhibitors, or targeting moieties in more complex systems by means of a methodology that screens small molecules based on protein affinity; (ii) decorate a self-assembling supramolecular system at different positions, making it responsive to a complementary protein with the aim of exploring differences in disassembly and sensitivity of the release of …


Push-Pull Molecules: Models And Polymer Building Blocks For Organic Photovoltaic Applications, Raymond Devaughn Jan 2014

Push-Pull Molecules: Models And Polymer Building Blocks For Organic Photovoltaic Applications, Raymond Devaughn

Masters Theses 1911 - February 2014

Several fluorenone alkynyl based oligo conjugated molecules were synthesized and characterized. Most compounds exhibited UV-Vis absorption onset at ca. 500 nm and a PL emission onset of ~329-370 nm, with excimer emission suspected from most systems near ~530-560 nm. Experimentally determined EHOMO and ELUMO energies range from -6.02 to -5.73 eV and -3.47 and 3.55 eV, respectively, with the lowest experimental Eg lying at -2.26 eV for 2-(trimethoxyphenylacetylene)-fluorenone. Cyclic voltammetry indicates quasi-reversible reduction for all systems, with 2,7-bis(nitrophenylacetylene)fluorenone exhibiting a high reduction potential of -1.25 eV. Only 2,7-bis(trimethoxyphenylacetylene)fluorenone exhibited a quasi-reversible oxidation, due to electron rich methoxy …