This work discusses the effect of photo-alignment in a liquid-crystal film that is doped with nanoparticles and azo-dye. The vertical alignment that is induced by nanoparticles of polyhedral oligomeric silsesquioxanes can be changed into homogeneous alignment by the absorption of photo-excited azo-dye. Both electro-optical and surface properties are analyzed to confirm this phenomenon. An electrically tunable polarization-dependent LC phase grating is produced using the method. By this method, we also present a transflective liquid crystal display with a single cell-gap in a dual-alignment configuration. This dual structure was fabricated via a single-step laser-light exposure through a photomask. The vertical alignment induced by nanoparticles of polyhedral oligomeric silsesquioxanes can be changed into a homogeneous alignment via absorption of photo-excited azo dye. The LC molecules at the transmissive and reflective pixels are homogeneous and hybrid alignment, respectively, at which optimal phase retardations of half and quarter wavelengths are achieved. Both nanoparticle- and azo-dye-induced vertical and homogeneous alignments are non-contact alignment processes and have potential for practical application.

The strong electromagnetic field that is induced at the surface of a plasmonic nanoparticle can be utilized for many important applications, including spectroscopic enhancement and electromagnetic waveguides. The focus of this thesis is to study some of the properties of induced plasmonic fields around metal nanoparticles. Current methodologies for fabricating nanoparticles are discussed, including lithography and colloidal synthesis. This dissertation includes studies on plasmonic driven nanoparticle motion of surface supported gold nanoprisms from a substrate into solution via a femtosecond pulse. The mechanism of particle motion is discussed and the stability of the unprotected nanoprisms in solution is studied. Fundamental plasmonic near-field coupling between two plasmonic nanoparticles is also examined. Experimental results using electron beam lithography fabricated samples are used to explicitly describe the plasmonic coupling between dimers as a function of the nanoparticle size, shape, and orientation. These variables are systematically studied and the dependence is compared to mathematically derived functional dependencies in order to model and predict the effects of plasmonic coupling. As an extension, the coupling between plasmonic nanoparticles is shown in a common application, surface enhanced Raman scattering. The final chapter is devoted to an investigation of the nature of nanocatalysis, homogeneous and heterogeneous, for several reactions using metal nanoparticles.

Nanostructures and properties of blends of homopolymer and elastomeric block copolymer nanoparticles were studied focusing on the effect of morphology and the viscoelastic properties on blends. The cylindrical and lamellar morphology of PS-b-PI copolymer was employed to generate the morphology of elastomeric nanoparticles such as nanofiber and nanosheet. The particles were synthesized using cold vulcanization process. The vulcanization process using sulfur monochloride (S2Cl2) was used to preserve the morphologies. The crosslinking density of block copolymer was controlled by exposure time of crosslinking agent in the chamber. The blend samples for DMA and rheometer were prepared using solvent casting process. The diameter and thickness of nanofiber and nanosheet obtained by the process were ~40 nm and ~70 nm, respectively. The rheological and dynamic mechanical properties of the blends of polystyrene (PS) and elastomeric nanoparticles were studied in terms of morphology and crosslinking density. The effect of core PI size also investigated and discussed. Based on these viscoelastic results, the theoretical percolation threshold was calculated and compared with experimental results. It is demonstrated that block copolymer is a facile method to generate elastomeric nanoparticles using cold vulcanization and viscoelastic properties can be tuned with addition of nanoparticles.

The major goals of this thesis were to (1) design and synthesize a supported catalyst with well-defined monodisperse palladium nanoparticles evenly distributed throughout an inorganic oxide substrate with tunable porosity characteristics, (2) demonstrate the catalytic activity of this material in the decarboxylation of long chain fatty acids and their derivatives to make diesel-length hydrocarbons, (3) elucidate the deactivation mechanism of supported palladium catalysts under decarboxylation conditions via post mortem catalyst characterization and develop a regeneration methodology thereupon, and (4) apply this catalytic system to a real low-value biofeedstock. In an effort to maximize loading and minimize mass transfer limitations, mesoporous silica MCF was synthesized as catalyst support. Functionalization with various silane ligands facilitated even distribution of palladium precursor salts throughout the catalyst particle, and, after reduction, monodisperse palladium nanoparticles approximately 2 nm in diameter. The Pd-MCF catalyst showed high one-time activity in the decarboxylation of fatty acids to hydrocarbons in dodecane at 300 °C. Subsequent reactions were performed on acid derivatives to elucidate a decarboxylation reaction pathway. The catalyst experienced severe deactivation after only one use and substantial effort was put into elucidating the nature of this deactivation via post mortem catalyst characterization. The deactivation was found not to be caused by nanoparticle sintering, agglomeration or ripening, but instead by organic deposition, mainly of reactant acid. A regeneration methodology was developed and subsequent catalyst reuse exhibited high activity. Finally, the Pd-MCF catalyst was applied to a wastewater-derived brown grease from a poultry rendering facility, in an unpolished and polished form. The latter was successfully decarboxylated to diesel-length hydrocarbons with high conversion and selectivity.

The literature on nanomaterials has been flooded with new shapes, sizes, and compositions of nanostructures. The process of developing and characterizing these particles has been broadly accomplished and many interesting and promising properties have been revealed for application in current and developing technologies. In particular, the phenomenon of surface plasmon resonance seen in metallic gold and silver nanoparticles has drawn substantial interest. It has been established that the electromagnetic fields surrounding plasmonic particle surfaces can influence the properties of nearby systems, causing them to experience effects such as enhanced absorption and emission of light or drastically increased conductivity. For this reason, plasmonic nanoparticles are being applied to an endless number of applications for new materials. This thesis investigated the effects of silver nanocube (AgNC) arrays on the photophysical properties of poly(paraphenyleneethynylene) (PPE) fluorescent polymers, a particularly relevant material to the applications of organic-electronics. AgNCs were selected because of their particularly strong plasmonic field, which is enhanced at the sharp features of the cubes. The PPE polymer is an exceptionally fluorescent conjugated polymer that often serves as a building block for polymer-based sensing applications. By monitoring the absorption and emission of the PPE polymer, a better understanding of plasmonic effects on this polymer system was obtained. Compression of the monolayer of AgNCs on the surface of a Langmuir-Blodgett trough can be used for control of interparticle distance and, thus, the plasmon field intensity felt by an adsorbed layer of PPE polymer. In the Chapter 4, PPE (n = 15) emission was monitored as a function of the AgNC plasmonic field. A two-photon process was found to explain the unusual increase then decrease of the fluorescence intensity. This observation was attributed to exciton-exciton annihilation processes within the polymer. The annihilation process is initiated by large enhancements of the polymer absorption rate when plasmonic fields are at their highest (when the AgNCs are compressed to short interparticle distances). In chapter 5, the optical properties of PPE polymers as a function of their chain length and the AgNC density were examined. A simple study was conducted to consider the conformational/geometrical effects on PPE that were caused by the deposition of PPE onto the AgNC topography. In this study, the structure of the absorption and emission profiles were evaluated and used as evidence of polymer interchain interactions, planarization, and even the potential generation of oligomeric species through breaking of conjugation. Fundamental interactions between materials must be evaluated and optimized prior to their use in devices. This thesis serves to shed a little bit of light on the interaction of a well-defined plasmonic particle with a conjugated polymer. The Langmuir-Blodgett technique serves as a critical tool in applying these colloidally produced nanoparticles to 2D arrays in practical applications. The observation of exciton-exciton annihilation at low-energy excitation is an entirely new phenomenon that was initiated by the plasmonic properties of metal nanoparticles. It is the hope of the author that the results contained herein can aide in the use of plasmonic nanoparticles in future devices.

The UV-Visible spectra of a-C composites and nano composites have provided a very useful information about the electronic states and band structure. The UV-Visible spectra of a-C as well as nanoparticle are qualitatively similar. They do not show any absorption cutoff in wavelength (_max). In fact they are good absorbers of UV-Visible light in whole range. Composites show some absorptions which could be the combined effect of filler as we as host matrix. Since there is no _max, hence it is very unlikely to define any optical band gap. The nanoparticle is a good absorber in midinfrared compared to a-C. That may be due to presence of complicated kind of vibrational modes of carbon cased nanoparticle.Besides Fe3C also produces some additional modes. With kind of spectrum we have it is difficult to identify the different modes unambiguously for nanoparticle. The combined effects of filler as well as host polymer are reflected in both sets of composites. A new absorption is observed in a-C as well as in nanoparticle composites at 2370 cm−1 and 3462 cm−1 respectively. This peak may arise in composites due to interaction between filler and host matrix. The thermo gravimetric analysis is a useful characterization techniques for polymer and composites. It gives the information about the stability, phase change, degradation, chemical reaction and many more. The a-C composites as well as nano composites are stable up to 200_ C. These composites can be safely used for any practical purpose below this temperature. During the synthesis of composites the filler does not take part in any reaction. This fact is reflected in the DTG curve. The composites degrade in the way host polymer degrades.

Polyelectrolyte complexation is a rapidly growing field with applications in functional multilayer (PEM) and nanoparticle (PEC) generation, where PEM films are deposited using Layer-by-Layer technique initiated by Decher and PECs are prepared using mixing-centrifugation technique initiated by our group. Its advantages (e.g. easy preparation) result in various applications in aqueous solution, especially in pharmaceutical and biomedical fields. Therefore, the objectives in this study are to explore interesting applications of polyelectrolyte complexation in the field of low molecular chiral compound and high molecular protein binding. Due to the rapidly growing demands for preparing optically pure compounds in the pharmaceutical field, herein, enantiospecific PEM and PEC were prepared using chiral polyelectrolytes (e.g. homo-polypeptide) and their ability of chiral recognition was investigated by ATR-FTIR, UV/Vis etc.. Chiral PEM and PEC showed pronounced enantiospecificity for both small (amino acids, vitamin) and large (protein) chiral compounds. This chiral recognition is performed by a diffusion process of chiral compounds into PEM based on the structures of chiral selector (PEM, PEC) and chiral probes (chiral compounds). However, the influences, e.g. pH value, ionic strength, surface orientation etc., were found to affect significantly the enantiospecificity. Beside planar substrates, porous membranes (e.g. PTFE) were modified using chiral PEM and successfully applied in enantiospecific permeation. Additionally, protein binding properties of PEC particle dispersions or PEC particle films were also studied. Due to the properties of polyelectrolytes used for PEC (e.g. molecular weight, charge density) and proteins (e.g. isoelectric point, size, hydrophobicity), PEC showed different uptake characteristics towards different proteins. Electrostatic and hydrophobic interaction as well as counterion release force were considered as possible driving forces for protein binding.

<p>Polymeric nanoparticles are potential candidates as carriers for pharmaceutical agents. Development of such nanoparticles generally requires molecules immobilized on the particle surfaces to ensure biocompatibility and/or targeting abilities. Following particle preparation and surface modification, excess reagents must be removed. Ultracentrifugation, which is the most widely used purification technique as per today, is not feasible in industrial applications. In this diploma work, tangential flow filtration is studied as an alternative purification method which is better suited for implementation in a large-scale process.</p><p>Comparison of ultracentrifugation and tangential flow filtration in diafiltration mode for purification of nanoparticles, indicate that they are comparable with respect to particle stability and the removal of the surfactant SDS from methacrylic anhydride nanoparticles. The purification efficiency of tangential flow filtration is superior to that of ultracentrifugation. Conductivity measurements of filtrates and supernatant liquids show that a stable conductivity value can be reached 6 times faster in filtration than in centrifugation with equipment and settings used. This conductivity arises from several types of molecules, and the contribution from surfactant molecules alone is not known. However, protein adsorption on the particles indicates successful removal of surfactant. Conductivity and tensiometry were evaluated as potential methods to quantify surfactant in solutions, but both proved unsatisfactory.</p><p>Using bovine serum albumin as a model protein, the extent of immobilization to nanoparticles is evaluated at different pH. A maximum amount of 6,8 mg/m2 is immobilized, whereof an unknown part is covalently bound. This coverage is achieved at pH 4,0 and is probably partly due to low electrostatic repulsion between particle and protein. An estimation of 2,0 µmol covalently bound BSA per gram of nanoparticles corresponds to 5,3 mg/m2 and a surface coverage of 76%. Removal of excess reagents after surface modification is done with ultracentrifugation instead of filtration, as particle aggregates present after the immobilization reaction might foul the membrane.</p>

Cardiovascular disease is the leading cause of morbidity and mortality in developed nations, and heart disease is predicted to remain the leading killer for the foreseeable future. Acute myocardial infarctions—nearly 1.1 million annually occurring in the U.S. alone—are the major cardiovascular disease subgroup. Current treatments for myocardial infarction are limited to interventions that serve to mitigate the initial insult, but clinical applications to protect or regenerate damaged myocardium are lacking. This dissertation examines three therapeutic systems to treat the infarcted heart. First, the decoration of a polymeric nanoparticle with N-acetylglucosamine for the uptake of anti-­apoptotic therapeutics to ameliorate cardiomyocyte cell death. Second, novel dendrimeric structure architecture to allow for regio­selected decoration of ligands to induce angiogenesis. Third, exosomes secreted from hypoxic cardiac progenitor cells as a naturally derived therapeuticfor angiogenesis and anti-fibrosis, and to provide bio-inspired clues for future therapies.

Nanoparticles are promising platforms for biomedical applications ranging from diagnostic tools to therapeutic delivery agents. During the course of these applications, nanoparticles are exposed to a complex mixture of extracellular serum proteins that nonspecifically adsorb onto the surface. The resulting protein layer, or protein "corona," creates an interface between nanoparticles and the biological environment. Protecting the nanoparticle surface can reduce protein adsorption, but complete inhibition remains a challenge. As a result, the corona, rather than the nanoparticle itself, mediates the cellular response to the nanoparticle. The following dissertation describes the fundamental characterization of the cellular binding of charged nanoparticles, interactions of protein-nanoparticle complexes with cellular receptors, and the structural and thermodynamic properties of adsorbed corona proteins.