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Full-Text Articles in Physical Sciences and Mathematics
Fluorescent Conjugated Polymer Dots For Single Molecule Imaging And Sensing Applications, Changfeng Wu
Fluorescent Conjugated Polymer Dots For Single Molecule Imaging And Sensing Applications, Changfeng Wu
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While single molecule imaging and sensing hold the promise of providing unprecedented detail about cellular processes, many advanced applications are limited by the lack of appropriate fluorescence probes. In many cases, currently available fluorescent labels are not sufficiently bright and photostable to overcome the background associated with various autofluorescence and scattering processes. This dissertation describes research efforts focused on the development of a novel class of fluorescent nanoparticles called conjugated polymers dots (CPdots) for single molecule fluorescence detection. The CPdots contain highly fluorescent π-conjugated polymers that have been refined over the last decades as the active material in polymer light-emitting …
Hybrid Bond-Order Potential For Silicon, Suleiman Oloriegbe
Hybrid Bond-Order Potential For Silicon, Suleiman Oloriegbe
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ABSTRACT
A new hybrid bond-order potential for silicon is developed. The functional form of the potential is derived from hybrid of expressions from empirical bond-order formalism and first principles approximations. The total energy is expressed as the sum of attractive, repulsive and promotion energies. By introducing a screening function derived from approximations to first principles expressions, the potential is made long-ranged by allowing covalent interactions beyond the first nearest neighbor shell of atoms in agreement with quantum mechanical descriptions of the bonding in silicon. Environment-dependent promotion energy is introduced that accurately accounts for energetic interactions due to changes in hybridization …
Structure And Transport Characteristics Of Highly Rigid Ionomers, Lilin He
Structure And Transport Characteristics Of Highly Rigid Ionomers, Lilin He
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The structure and transport characteristics in a novel family of ionomers consisting of a hydrophobic polyphenylene backbone substituted by sulfonic acid functionalized phenyl side chains (sPPs) have been investigated. These polymers have potential applications in electrochemistry as well as separation both as membranes and thin films. The bulk structure as a function of hydration has been explored by X-ray and neutron scattering. Interfacial structure was studied by AFM and neutron reflectometry. The characteristics of water in the bulk were studied by NMR and FTIR and that in thin films by neutron reflectometry.
The sPPs exhibit characteristic structure due to their …
Strategies For Expanding The Halogen Bonding Periodic Table And Desigining Complementary Halogen/Hydrogen Bonding Synthons, Hadi Arman
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Halogen bonding is the donation of electron density from an electron donor, such as N, O, S, Se atoms, to an electron acceptor such as a dihalogen or organohalogen. This interaction plays an important role in biological systems, such as the thyroid gland and is useful in many other fields such as drug design, crystal engineering, synthetic chemistry, material science and bioinorganic chemistry. However, currently there is a lack of information for this interaction in systems involving organoiodines with sulfur and selenium electron donors.
A variety of sulfur and selenium Lewis base donors were investigated with various organoiodines. The main …
Synthesis, Electronic Structure, And Reactivity Of Endohedral Metallofullerenes And Other Endohedral Carbon Nanostructures, Bevan Elliott
Synthesis, Electronic Structure, And Reactivity Of Endohedral Metallofullerenes And Other Endohedral Carbon Nanostructures, Bevan Elliott
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The discovery in 1985 of fullerenes combined with the development of STM beginning in 1981 is credited as the starting point of the current nanoscience revolution. Endohedral fullerenes, discovered shortly after, have drastically different electronic properties when compared with the empty fullerenes. This dissertation has as its central focus the synthesis and electronic properties of endohedral metallofullerenes and other endohedral nanostructures.
The opening two chapters give a brief background of the discovery of fullerenes. A comprehensive literature list is given for the various families of trimetallic nitride endohedral fullerenes as well as other large endohedral metallic cluster fullerenes. Finally, a …
Structure And Dynamics Of Poly (Para-Phenyleneethynylene)S In Solutions And Thin Films, Yunfei Jiang
Structure And Dynamics Of Poly (Para-Phenyleneethynylene)S In Solutions And Thin Films, Yunfei Jiang
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This research focuses on the structure and dynamics of a family of rigid polymers, poly(para-phenyleneethynylene)s (PPEs) in solutions and thin films using small angle neutron scattering, neutron spin echo, nuclear magnetic resonance, X-ray scattering, atomic force microscopy and fluorescence spectroscopy. The effects of the solvent and the side chain on the molecular conformation and the association of PPEs have been investigated.
In dilute solutions, the phase diagram of dinonyl PPE in toluene and cyclohexane exhibits three distinct phases. At higher temperatures, PPEs form molecular solutions with extended conformations in toluene and worm-like chains in cyclohexane. With decreasing temperatures, PPEs associate …