Tesis: "Functional nanoparticles"

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Campioli, Elisa. "Functional fluorescent organic nanoparticles". Phd thesis, Université Rennes 1, 2013. http://tel.archives-ouvertes.fr/tel-00954407.

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During the past two decades, increasing research attention has been devoted to nanomaterials (materials in the range of 10-100 nm) because of their unique optoelectronic properties. In particular, inorganic nanomaterials, such as quantum dots, metal-based nanoparticles and silica nanoparticles, have been investigated extensively. Instead, nanomaterials based on organic molecules are been subject of research only since very recent years. This thesis presents an extensive study of novel fluorescent organic nanoparticles and fluorescent organic binary and ternary nanoassemblies. In particular the attention is focused on the preparation and characterization of organic nanoparticles and new nanocomposites obtained from different types of small organic chromophores, their stabilization and the use of these materials for biological and optoelectronics applications.

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2

Gass, James. "Functional Magnetic Nanoparticles". Scholar Commons, 2012. http://scholarcommons.usf.edu/etd/4047.

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Nanoparticle system research and characterization is the focal point of this research and dissertation. In the research presented here, magnetite, cobalt, and ferrite nanoparticle systems have been explored in regard to their magnetocaloric effect (MCE) properties, as well as for use in polymer composites. Both areas of study have potential applications across a wide variety of interdisciplinary fields. Magnetite nanoparticles have been successfully dispersed in a polymer. The surface chemistry of the magnetic nanoparticle proves critical to obtaining a homogenous and well separated high density dispersion in PMMA. Theoretical studies found in the literature have indicated that surface interface energy is a critical component in dispersion. Oleic acid is used to alter the surface of magnetite nanoparticles and successfully achieve good dispersion in a PMMA thin film. Polypyrrole is then coated onto the PMMA composite layer. The bilayer is characterized using cross-sectional TEM, cross-sectional SEM, magnetic characterization, and low frequency conductivity. The results show that the superparmagnetic properties of the as synthesized particles are maintained in the composite. With further study of the properties of these nanoparticles for real and functional uses, MCE is studied on a variety of magnetic nanoparticle systems. Magnetite, manganese zinc ferrite, and cobalt ferrite systems show significant broadening of the MCE and the ability to tune the peak temperature of MCE by varying the size of the nanoparticles. Four distinct systems are studied including cobalt, cobalt core silver shell nanoparticles, nickel ferrite, and ball milled zinc ferrite. The results demonstrate the importance of surface characteristics on MCE. Surface spin disorder appears to have a large influence on the low temperature magnetic and magnetocalorie characteristics of these nanoparticle systems.

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3

Beyazit, Selim. "Functional nanoparticles for biomedical applications". Thesis, Compiègne, 2014. http://www.theses.fr/2014COMP2163.

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Cette thèse décrit le développement de nouvelles méthodes pour obtenir des nanoparticules fonctionnelles polyvalentes qui peuvent potentiellement être utilisées pour des applications biomédicales telles que la vectorisation de médicaments, des essais biologiques et la bio-imagerie. Les nanomatériaux sont des outils polyvalents qui ont trouvé des applications comme vecteurs de médicaments, la bio-imagerie ou les biocapteurs. En particulier, les nanoparticules de type core-shell ont attiré beaucoup d'attention en raison de leur petite taille, une relation surface/volume élevée, et une biocompatibilité. Dans ce contexte, nous proposons dans la première partie de la thèse (Chapitre 2), une nouvelle méthode pour obtenir des nanoparticules core-shell via la polymérisation radicalaire en émulsion et vivante combinées. Des particules cœurs de polystyrène de 30 à 40 nm, avec une distribution de taille étroite et portant à la surface des groupements iniferter ont été utilisés pour amorcer la polymérisation supplémentaire d'une couche de polymère. Des nanoparticules core-shell ont été préparées de cette façon. Différents types d’enveloppes : anionique, zwitterioniques, à empreintes moléculaires, thermosensibles, ont ainsi été greffées. Notre méthode est une plate-forme polyvalente permettant d'ajouter des fonctionnalités multiples soit dans le noyau et/ou l'enveloppe pour les études d'interaction cellulaire et de toxicité, ainsi que des matériaux récepteurs pour l'imagerie cellulaire. Dans la deuxième partie de la thèse (Chapitre 3), nous décrivons un procédé nouveau et polyvalent pour la modification de surface des nanoparticules de conversion ascendante (UCP). Ce sont des nanocristaux fluorescents dopés de lanthanides qui ont récemment attiré beaucoup d'attention. Leur fluorescence est excitée dans le proche infrarouge, ce qui les rend idéales comme marqueurs dans des applications biomédicales telles que les tests biologiques et la bio-imagerie, l'auto-fluorescence étant réduite par rapport à des colorants organiques et les quantum dots. Cependant, les UCP sont hydrophobes et non-compatible avec les milieux aqueux, donc une modification de leur surface est essentielle. La stratégie que nous proposons utilise l'émission UV ou visible après excitation en proche infrarouge des UCP, comme source de lumière secondaire pour la photopolymérisation localisée de couches minces hydrophiles autour les UCP. Notre méthode offre de grands avantages comme la facilité d'application et la fonctionnalisation de surface rapide pour fixer divers ligands, et fournit une plateforme pour préparer des UCP encapsulée de polymères pour des différentes applications. Des hydrogels stimuli-sensibles sont des matériaux qui changent leurs propriétés physicochimiques en réponse à des stimuli externes tels que la température, le pH ou la lumière. Ces matériaux intelligents jouent un rôle critique dans des applications biomédicales telles que la vectorisation de médicaments ou l'ingénierie tissulaire. La troisième partie de cette thèse (Chapitre 4) propose un nouveau procédé de préparation d'hydrogels photo et pH sensible. Deux composantes, l'un photosensible à base dl'acide 4-[(4-méthacryloyloxy) phénylazo] benzoïque et l'autre cationic contenant des unités 2-(diéthylamino)éthyl méthacrylate, ont été synthétisés. Leur association donne des particules monodispersées de 100 nm photo et pH sensibles. Ces nanoparticules peuvent être potentiellement utilisées pour la vectorisation de médicaments, en particulier de biomolécules telles que protéines ou siARN. En conclusion, nous avons conçu plusieurs nouvelles méthodes efficaces, polyvalentes, génériques et facilement applicables pour obtenir des nanoparticules et nanocomposites de polymères fonctionnels qui peuvent être appliqués dans de différents domaines biomédicaux comme la vectorisation de médicaments, les biocapteurs, les tests biologiques et la bio-imagerie
This thesis describes the development of novel methods to obtain versatile, functional nanoparticles that can potentially be used for biomedical applications such as drug delivery, bioassays and bioimaging. Nanomaterials are versatile tools that have found applications as drug carriers, bioimaging or biosensing. In particular, core-shell type nanoparticles have attracted much attention due to their small size, high surface to volume ratio and biocompatibility. In this regard, we propose in the first part of the thesis (Chapter 2), a novel method to obtain core-shell nanoparticles via combined radical emulsion and living polymerizations. Polystyrene core seeds of 30-40 nm, with a narrow size distribution and surface-bound iniferter moieties were used to further initiate polymerization of a polymer shell. Core-shell nanoparticles were prepared in this way. Different types of shells : anionic, zwitterionic, thermoresponsive or molecularly imprinted shells, were thus grafted. Our method is a versatile platform with the ability to add multi-functionalities in either the core for optical sensing or/and the shell for cell interaction and toxicity studies, as well as receptor materials for cell imaging. In the second part of the thesis (Chapter 3), we describe a novel and versatile method for surface modification of upconverting nanoparticles (UCPs). UCPs are lanthanide-doped fluorescent nanocrystals that have recently attracted much attention. Their fluorescence is excitated in the near infrared, which makes them ideal as labels in biomedical applications such as bioimaging and bioassays, since the autofluorescence background is minimized compared to organic dyes and quantum dots. However, UCPs are hydrophobic and non-compatible with aqueous media, therefore prior surface modification is essential. The strategy that we propose makes use oft he UV or Vis emission light of near-infrared photoexcited upconverting nanoparticles, as secondary light source for the localized photopolymerization of thin hydrophilic shells around the UCPs. Our method offers great advantages like ease of application and rapid surface functionalization for attaching various ligands and therefore can provide a platform to prepare polymeric-encapsulated UCPs for applications in bioassays, optical imaging and drug delivery. Stimuli responsive hydrogels are materials that can change their physico-chemical properties in response to external stimuli such as temperature, pH or light. These smart materials play critical roles in biomedical applications such as drug delivery or tissue engineering. The third part of the thesis (Chapter 4) proposes a novel method for obtaining photo and pH-responsive supramolecularly crosslinked hydrogels. Two building blocks, one containing photoresponsive 4-[(4-methacryloyloxy)phenylazo] benzoic acid and the other, consisting of cationic 2-(diethylamino)ethyl methacrylate units, were first synthesized. Combining the two building blocks yielded photo and pH responsive monodisperse 100-nm particles. These nanoparticles can be eventually utilized for drug delivery, especially delivery of biomolecules such as siRNAs or proteins. In conclusion, we have designed several new efficient, versatile, generic and easily applicable methods to obtain functionalized polymer nanoparticles and nanocomposites that can be applied in various biomedical domains like drug delivery, biosensing, bioassays and bioimaging

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4

Wan, Congshan. "Functional nanoparticles: synthesis and simulation". Thesis, Georgia Institute of Technology, 2014. http://hdl.handle.net/1853/53074.

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Functional nanoparticles have garnered considerable attention due to their intriguing physical properties at the nanoscale for a broad range of applications, such as photocatalysis, capacitive energy storage, thermoelectric power generation, solar energy harvesting, flexible and transparent electronics, drug delivery, biomolecular electronics, and analytic chemistry, etc. Successful synthesis of nanoparticles and precise control over their shapes are critical to achieving desired functions. In the first part of my thesis, an effective synthetic route to plain nanoparticles is briefly introduced. Based on this general route, the synthesis of solid iron oxide nanoparticles and a slightly modified synthetic method of solid silica nanoparticles are presented in detail. In the second part of my thesis, simulation of optical absorption spectra and plasmonic near-field maps of gold nanoparticle and gold/titanium oxide nanoparticle are explored, and the effectiveness of simulation in predicting, optimizing, and guiding experimental design is emphasized.

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5

Khanal, Manakamana. "Functional nanoparticles for biological applications". Thesis, Lille 1, 2014. http://www.theses.fr/2014LIL10100/document.

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Les nanoparticules fonctionnalisées continuent de susciter beaucoup d’interêt dans les applications biomédicales et les essais biologiques. Elles sont devenues un élément clé dans la recherche en nanobiotechnologie. Un des axes primordiaux des travaux de recherche est le développement de stratégies polyvalentes de fonctionnalisation de surface pour différentes nanoparticules allant de nanostructures de diamants à des nanoparticules d'oxyde de fer, des particules de silice et des nanocapsules lipidiques. Un des objectifs en particulier a été l’introduction de diverses fonctionnalisations sur les mêmes nanoparticules en utilisant soit des ligands dérivés de la dopamine ou soit par chimie « click » de Cu(I) catalysé. Il en résulte des nanostructures bien dispersées fonctionnalisées avec différents ligands à leurs surfaces. Les applications de ces nanostructures pour l'inhibition des infections virales et pour la délivrance de gènes ont été étudiées. En effet, l'inhibition de l'entrée du VHC a été identifiée comme étant une stratégie thérapeutique potentielle. Il a pu être démontré que différentes nanoparticules peuvent être efficacement conçues pour afficher les propriétés de lectine et se comporter donc comme des inhibiteurs efficaces d'entrée du virus in vitro. Les pseudo-lectines étudiées ici comprennent les nanoparticules dérivées du fer, de silice, du diamant et des nanocapsules lipidiques comportant toutes des fragments d’acide boronique attachés à leurs surfaces.Par ailleurs, le potentiel des nanoparticules de diamant pour la délivrance de gènes a été étudié
Functionalized nanoparticles continue to attract interest in biomedical applications and bioassays and have become a key focus in nanobiotechnology research. One of the primal focuses of the research work was the development of versatile surface functionalization strategies for different nanoparticles ranging from diamond nanostructures to iron oxide nanoparticles, silica particles and lipid nanocapsules. One particular aim was the introduction of various functionalities onto the same nanoparticles using either dopamine-derived ligands or Cu(I) catalyzed “click” chemistry strategies. This resulted in well-dispersed nanostructures with different ligands present on the surface of the nanostructures. The possibilities to use such nanostructures for the inhibition of viral infections and for gene delivery were investigated. Indeed, inhibiting the entry of HCV has been identified as a potential therapeutic strategy. It could be demonstrated that various nanoparticles can be efficiently engineered to display “lectin-like” properties and indeed behave as effective viral entry inhibitors, in vitro. The pseudo-lectins investigated here include iron-, silica-, diamond-, (lipid nanocapsule)-derived nanoparticles all featuring surface-attached boronic acid moieties. In parallel to work on HCV entry inhibition, the potential of diamond nanoparticles as gene delivery system was investigated. Water dispersible and biocompatible polypegylated diamond particles were prepared using different dopamine ligands and their effect on gene delivery has been studied

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6

Pawluk, Tiffany. "Iridium nanoparticles : a density functional theory study /". Available to subscribers only, 2005. http://proquest.umi.com/pqdweb?did=1075692711&sid=20&Fmt=2&clientId=1509&RQT=309&VName=PQD.

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7

Aarons, Jolyon. "Density functional theory applied to metallic nanoparticles". Thesis, University of Southampton, 2018. https://eprints.soton.ac.uk/418013/.

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This thesis will focus on DFT for calculations of large metallic nanoparticles. It will show new algorithms that were developed for reduced scaling DFT methods for metals; the testing, verification and design of new descriptors for predicting the catalytic activity of metallic nanoparticles; application of large-scale DFT calculations to model nanoparticle sequences to show size and oxygen adsorption coverage trends, and finally the application of these techniques and knowledge to perform a study of oxygen adsorption on real-world, experimentally determined platinum nanoparticles in collaboration with the Nellist group at Oxford materials. We explore the binding of atomic oxygen to cuboctahedral platinum nanoparticles of up to 1000 atoms using DFT calculations in ONETEP. We demonstrate convergence to the infinite slab limit for single oxygen adsorption in chapter 4 and correlate adsorption strength against popular descriptors for catalytic activity, such as the d-band centre approach. This approach is possible because of work which will be described in chapter 3 to implement angular momentum projected density of states calculations in ONETEP. The effects of oxygen coverage on the Pt55 and Pt147 cuboctahedral nanoparticles will also be analysed, which serves to advance our simulations towards realistic conditions. We show in our investigation into half monolayer, hemispherical oxygen coverage on platinum nanoparticles that oxygen tends to gravitate towards the edges and lower coordinated sites in the nanoparticle and away from the centres of facets. This effect correlates with the site specific, single oxygen adsorption energies on Pt309 and experimental platinum nanoparticles which is presented in chapter 5. We show that when subdividing the binding of monolayers of oxygen into only (111) and (100) facets that these have a lower adsorption strength per oxygen atom than combined (100) and (111) facets as well as lower binding strength than single oxygen adsoprtion. In the next part of the study, which is discussed in chapter 5, we show large scale DFT calculations on real platinum nanoparticles, which were measured by the Nellist group at Oxford materials using advanced electron microscopy techniques. These DFT calculations provide the electronic structure of the experimentally measured nanoparticles, which allowed us to apply electron density based catalytic activity descriptors to the nanoparticles, such as the d-band centre approach, or our own electronic density based descriptor described in chapter 3. We find that surface roughness of the experimental nanoparticles contributes to more potential oxygen binding sites with low electron density, which correlatates with stronger oxygen adsorption strength in our model, when compared with the relative smoothness of cuboctahedral and truncated octahedral facets. In the analysis which is presented in chapter 5, the proportion of sites which lie within 0.2 eV of the oxygen binding strength required for optimum catalytic activity is predicted with high efficiency, based on our catalytic activity descriptor. Finally, in chapter 6 we describe a new method for large scale DFT calculations on metallic systems which we call the AQuA-FOE method. We show how this method can have a computational cost which increases effectively linearly with the number of atoms. The AQuA-FOE method works by implicitly heating and quenching the electrons in the system to find the oneparticle density matrix, while conserving the electron number. We show validation of this method inside the EDFT procedure by comparing numerically with the diagonalisation based EDFT that is already implemented in ONETEP showing agreement in the energies to better than 10⁻⁵ EH per atom. We will also demonstrate the effectively linear-scaling computational cost of our method with calculation times on regular truncated octahedral Palladium nanoparticles ranging from 2,406 to 12,934 atoms.

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8

Waltz, Florian [Verfasser]. "Inorganic nanoparticles for functional coating applications / Florian Waltz". Hannover : Technische Informationsbibliothek und Universitätsbibliothek Hannover (TIB), 2012. http://d-nb.info/1030087733/34.

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9

Alayo, Bueno Nerea. "Fabrication methods for functional nanoparticles and interdigitated nanoelectrodes". Doctoral thesis, Universitat Autònoma de Barcelona, 2013. http://hdl.handle.net/10803/129122.

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Esta tesis presenta el desarrollo de nuevos métodos de nanofabricacion para la preparación de nanopartículas funcionales y electrodos interdigitados. El trabajo incluye el diseño, fabricación y caracterización de diferentes métodos que solucionan algunas de los retos que presenta la nanotechnología hoy en día. Estas estrategias aprovechan las ventajosas propiedades que surgen de las dimensiones nanometricas. En primer lugar, se ha desarrollado un método que facilita el estudio de la conductividad de una única nanopartícula. Este método está basado en la preparación de una plataforma donde se deposita una capa muy fina de un nuevo nanocompuesto. El nanocompuesto está formado de nanocristales embebidos en una resina altamente aislante. Esto facilita la conexión de las nanopartículas usando una punta de AFM mientras estas están aisladas eléctricamente del medio. Se exponen el diseño y optimización de la técnica, además de los resultados preliminares obtenidos de las medidas eléctricas. Además, se han fabricado nanopartículas metálicas mediante litografía por nanoimprint. Esta técnica es un avance en el estado del arte, ya que permite la fabricación de nanoestructuras con una alta relación de aspecto, facilita el liftoff, y proporciona una alternativa para obtener nanopartículas de diferentes tamaños, formas y materiales, incluso combinaciones de estos. También se ha evaluado el comportamiento de las partículas como plasmones de resonancia para su aplicación en sensores LSPR (localized surface plasmon resonance). Se ha presentado el desarrollo de la fabricación y caracterización de nanoelectrodos interdigitados para usar como (bio)sensores, incluyendo la adaptación de métodos de nanolitografía y encapsulados. La caracterización funcional de los nanoelectrodos interdigitados demuestra una mejoría en la selectiva detección de dopamina en presencia de ácido ascórbico debido a la miniaturización de los dispositivos. Los resultados experimentales han sido confirmados mediante simulaciones de elementos finitos. En esta tesis, se ha demostrado que los nuevos métodos desarrollados permiten la fabricación de nanoestructuras y nanodispositivos con nuevas y mejoradas funciones. Además, los métodos presentados pueden ser aplicados a otras áreas como los biosensores, la nano/microelectrónica, medicina o energía.
This thesis presents the development of novel nanofabrication methods for the preparation of functional nanoparticles and interdigitated nanoelectrodes. The work includes the design, fabrication and characterization of different approaches that overcome some of the current challenges in nanotechnology. These approaches take advantage of the enhanced properties that arise from the nanometer scale dimensions. First, a novel method to study the electrical conductivity of single nanoparticles has been developed. This method is based on the preparation of a platform where a thin film of a new nanocomposite is placed. The nanocomposite is composed of nanocrystals embedded in a highly isolating resist. It facilitated the connection of the particles by AFM tip while keeping them electrically isolated from their surroundings. The design and optimization of the method, as well as the preliminary electrical results have been exposed. Moreover, metallic nanoparticles arrays have been fabricated by nanoimprint lithography. This technique is a step forward in the nanoimprint lithography’s state of the art, since allows the fabrication of high aspect ratio nanostructures, facilitates the lift-off, provide alternative to obtain nanoparticles of different size, shapes and materials, and even combination of them. Plasmonic resonance behavior of the particles has also been evaluated for their application as localized surface plasmon resonance (LSPR) sensors. In addition, fabrication and characterization of interdigitated nanoelectrodes to be used as (bio)sensors have been developed, including the adaptation of nanolithography methods and packaging strategies. The functional characterization of the interdigitated nanoelectrodes showed an improvement on the selective detection of dopamine in presence of ascorbic acid resulted from the miniaturization of the devices. The experimental results are correlated to finite element simulations. In this thesis, it is demonstrated that the new developed methods allow fabricating nanostructures and nanodevices with novel and enhanced functionalities. Moreover, the presented methods can be further applied to different areas, such as biosensors, nano/microelectronics, medicine or energy.

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10

Myakonkaya, Olesya. "Separation and Recovery of Functional Colloids and Nanoparticles". Thesis, University of Bristol, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.526011.

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11

Gao, Xin. "Novel development of functional magnetic nanoparticles for applications". Thesis, University of Reading, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.415544.

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12

Lim, I.-Im Stephanie. "Molecularly mediated assembly of nanoparticles towards functional nanostructures". Diss., Online access via UMI:, 2008.

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13

Ubaldo, Pamela Cabalu. "Towards Combined Computational and Experimental Studies on Toxicity of Silver Nanoparticles". OpenSIUC, 2015. https://opensiuc.lib.siu.edu/dissertations/992.

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Despite the growing applications of silver nanoparticles, toxicity information on this nanomaterial is still deficient. Conclusions on the toxicity of silver nanoparticles vary and atomic level toxicity mechanisms are not yet achieved. Consequently, our group conducted combined computational and experimental toxicity studies of silver nanoparticles (AgNPs). Toxicity of 10 nm citrate stabilized AgNPs on HepG2 cells were investigated. Experimental results show that the 10 nm citrate stabilized AgNPs begin to be toxic to HepG2 cells at a dosage that exceeds 1 ppm and LD50 was observed at 3 ppm. Elevated reactive oxygen species levels were seen upon exposure to AgNPs with the maximum at the LD50 concentration of 3 ppm. Normal protein regulation of HepG2 cells were affected by exposure to AgNPs. TEM images of HepG2 cells exposed to AgNPs reveal that AgNPs can penetrate and agglomerate inside the cells. Our preliminary computational study was guided by one of the widely accepted toxicity mechanism of AgNPs in which the nanoparticles dissolute to Ag+. The computational model was composed of a 1:1 ratio of silver and phospholipid head. The silver employed are in atomic and anionic form while the phospholipid head are the phosphocholine (PC) and phosphoethanolamine (PE), which are abundant in HepG2 cells. Computational study shows that the presence of Ag+ results in partial oxidation of both the phospholipid heads. Our preliminary experimental and computational studies lead us to develop new computational methods that can accurately predict oxidation potentials (HOMO), reduction potentials (LUMO), and absorption spectra that can be used in studying toxicity mechanism of AgNPs through the oxidation pathway. Thus, computational methods for cyclic voltammetry and absorption spectroscopy that use DFT and TD-DFT, respectively, were improved to provide more accurate electronic and optical properties. Cyclopenta-fused polycyclic hydrocarbons (CP-PAHs) with available experimental data for HOMO, LUMO, ΔEgap and absorption spectra and have potential application as AgNP stabilizers were used in developing the improved computational methods for cyclic voltammetry and absorption spectroscopy. The improved computational method for cyclic voltammetry was developed by accounting for the anion species that occur experimentally and by using B3LYP the best density functional in predicting the HOMO, LUMO and ΔEgap of CP-PAHs with overall MAE of 014 eV. The best absorption spectra otef CP-PAHs were predicted using B3LYP for geometry optimizations followed by TD-CAMB3LYP with MAE of 29 nm. All calculations of CP-PAHs were implemented using the 6-311g (d,p) basis set and tetrahydrofuran (THF) as solvent. These two developed computational methods were tested on a group of methyl triphenyl amine (MTPA) derivatives with available experimental data for HOMO, LUMO, ΔEgap and absorption spectra and have potential application as AgNP stabilizers. The new computational methods for cyclic voltammetry and absorption spectroscopy also provided the most accurate predicted electronic and optical properties of MTPA derivatives. Among the ten density functionals employed, prediction of HOMO, LUMO and ΔEgap were most accurate using B3LYP and B3PW91 with overall MAE of 0.31 eV and 0.27 eV, respectively. Absorption spectra of MTPA derivatives were still best predicted using the B3LYP/TD-CAMB3LYP method with MAE of 13 nm. All calculations of MTPA were implemented using the 6-31+g (d,p) basis set and dichloromethane as solvent.

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14

Yu, Zitian. "The Preparation of Gold Nanoparticles for Multi-Functional Surface". University of Akron / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=akron1428063689.

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15

Kemal, Lydia Materials Science &amp Engineering Faculty of Science UNSW. "Gold and silver nanoparticles: synthesis, characterization and functional properties". Publisher:University of New South Wales. Materials Science & Engineering, 2008. http://handle.unsw.edu.au/1959.4/43108.

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This thesis focuses on the shape-controlled metal nanoparticles for functional applications, covering the synthesis, characterization and optical properties. Three parts are mainly involved in this work, including, gold worm-like nanoparticles, silver nanoplates, and silver induced selenium nanowires. The first part focuses on a facile synthesis method for shape control of gold nanoparticles by treating an aqueous solution of chloroauric acid with sodium citrate and poly(vinyl pyrrolidone) (PVP), in which those worm-like nanoparticles were investigated by various advanced experimental characterizations combining density function theory (DFT) calculation. These nanoparticles can be used for optical sensing detection of ions in aqueous system. The second part involves the synthesis, growth, and optical properties of silver nanoplates (triangles and circular discs). Such nanoplates could be synthesized by a self-seeding co-reduction method at ambient conditions. In particular, molecular dynamics simulation is used to quantify the interaction energies between surfactant molecules and different facets of silver crystal. Such molecular information, together with measurements using x-ray diffraction (XRD), transmission electron microscopy (TEM), atomic force microscopy (AFM) and ultraviolet??visible (UV??vis) spectroscopy, has proven to be useful for understanding the growth mechanisms of silver nanoplates. The third part focuses on the template of silver nanoparticles for generating trigonal selenium (t-Se) nanowires. This technique exhibits some advantages in fabricating t-Se nanostructures, including no need to use stabilizers and sonichemical process and all operations being proceeded in aqueous media and at room temperature. Particularly it can successfully achieve the transformation from amorphous α-Se to crystalline t-Se in aqueous solution and this method would be useful for generating one-dimensional nanostructures with similar lattice parameter(s). It is considered that the technique for the shape-controlled metal nanoparticles can at least partially, be extended to other nanomaterials for functional applications.

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16

Raimondo, Corinna. "Photoresponsive gold nanoparticles : towards multi-functional organic electronics devices". Phd thesis, Université de Strasbourg, 2012. http://tel.archives-ouvertes.fr/tel-00954743.

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In the last three decades Organic Electronics emerged and established itself as an interdisciplinary field of science and as part of our daily life. Presently, the greatest scientific challenges in this field of research are two: the former relies on the improvement of devices efficiency which can be accomplished by using new materials, whereas the latter consist in the integration of multiple functionalities in a single device. To accomplish these goals one needs to develop a deep understanding on the fundamental physical-chemistry ruling the properties which are on the basis of organic electronics such as charge injection, charge transfer and transport. This PhD project reports the developing of efficient multicomponent electroactive self-assembled systems whose electro- and optical properties can be modulated, in devices, as a response to multiple external and independent stimuli. This goal has been achieved by engineering of the proper building blocks and the study of the the physico-chemical properties to be able to model all the mechanisms involved.

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17

Lapitan, Lorico Delos Santos. "Development of functional nanoparticles for biosensing and antibacterial applications". Thesis, University of Leeds, 2018. http://etheses.whiterose.ac.uk/21668/.

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PART 1 The ability of ultrasensitive detection of specific genes and discrimination of disease related single nucleotide polymorphisms (SNPs) is important for biomedical research and clinical disease diagnosis. Herein, we report an ultrasensitive approach for label-free detection and discrimination of full-match target-DNA from its cancer related SNPs by combining magnetic nanoparticle (MNP) capture and poly-enzyme nanobead signal amplification. It uses a MNP linked capture-DNA and a biotinylated signal-DNA to sandwich the target followed by ligation to offer high SNP discrimination: only the perfect-match target-DNA yields a MNP covalently linked biotinylated signal-DNA for subsequent binding to a neutravidin-horseradish peroxidase conjugate (NAV-HRP) and signal amplification. The use of polymer nanobeads each tagged with thousands of copies of HRPs greatly improves the signal amplification power, allowing for detection of 10 aM target-DNA with a large dynamic range of 5 orders of magnitude (0.01-1000 fM). Moreover, this sensor also offers excellent signal discrimination between the perfect-match gene and its cancer-related SNPs and can positively detect 1 fM perfect-match target-DNA in the presence of 100 fold excess of co-existing SNPs. Furthermore, it works robustly in clinical relevant media (e.g. 10% human serum) and gives almost identical SNP discrimination as that in clean buffers. This ultrasensitive SNP sensor appears to have excellent potential for rapid detection and diagnosis of genetic diseases. This study also reports the design of a MNP-DNAss-HRP nanoprobe for the label-free detection of DNA and ECOR-I. The Fe3O4 MNP were prepared by thermal decomposition and coated with silica by the reverse micelle method yielding core-shell nanoparticles. These silica coated MNP were modified with amino groups for further conjugation with DNA. In Design-1, the capture DNA contain DBCO and biotin group at the 5’ and 3’ end respectively. The capture DNA was linked to the amino modified MNP through copper free click chemistry approach. The NAV-HRP was linked to the DNA strands through biotin-strepatividin interaction. The MNP-DNA conjugates were further incubated with NHS-PEG~17-OCH3 to cap unreacted amines. In Design-2, the capture DNA also contain DBCO group at 5’ end but a thiol (-SH) group at 3’ end. The capture DNA strand was linked to MNP and the unreacted surface amines were blocked following the same strategy for Design-1. Incubation with maleimide-HRP led to the covalent linking of the enzyme to the DNA strands. The MNP-DNAss-HRP nanoprobes and target DNA are hybridized and the resulting double strand DNA contains specific sequence that is recognized and cleaved by ECOR-I. This releases thousands of HRP enzyme to the solution which in turn can catalyse a colourimetric reaction. Using Design-2, the optimal incubation temperature was 30 °C and 1 hour incubation time with ECOR-I. This approach can detect 10 U·mL-1 of ECOR-I and 1 nm of target DNA. PART 2 Silver nanomaterials have been widely utilized for antimicrobial applications. Silver nanoparticles (Ag NPs) have been used in many biomedical and environmental applications for many years. Interestingly, silver nanoclusters (Ag NCs) have emerged as a new class of silver nanomaterials and currently being investigated for its antibacterial properties. In this study, we report the antibacterial properties of Ag NPs and NCs that were synthesized using the same protocol and capped with the same dihydrolipoic acid (DHLA) based ligands against S. aureus and E. coli. These ligands were DHLA-EGn-NH2 (n=3,12), DHLA-PEGn-OCH3 (n ~17, 23) and DHLA-zwitterion. The Ag NC-DHLA and Ag NC-PEG~23-OCH3 inhibited S. aureus and E. coli with MIC results of 128, 64 and 64, 128 μg·mL-1 respectively. The Ag NPs were observed to be more effective antimicrobial agents as revealed by MIC results. The 5.7 nm Ag NP-zwitterion is the most potent antibacterial agent among all the Ag NPs tested with an MIC of 8 μg·mL-1 for both bacterial strains. This study demonstrated, for the first time, that the antibacterial properties of silver nanomaterials differ significantly when coated with different ligands. Moreover, surface coating and charge are most likely the key factors that control the antimicrobial efficacy of Ag NCs and NPs.

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18

Mahhouti, Zakaria. "Synthesis and characterization of functional monodispersed cobalt ferrite nanoparticles". Electronic Thesis or Diss., Amiens, 2019. http://www.theses.fr/2019AMIE0010.

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Dans le présent travail, les nanoparticules monodispersées à base de ferrite de cobalt ont été explorées pour leurs propriétés magnétiques et leur effet magnétostrictif, ainsi que pour une utilisation en tant que ferrofluide. Les nanoparticules ont été dispersées avec succès dans un solvant organique. La chimie de surface de la nanoparticule magnétique s'avère cruciale pour obtenir une dispersion haute densité homogène et bien séparée dans l'hexane. De plus, l'acide oléique a été utilisé pour modifier la surface des nanoparticules de ferrite de cobalt et permettre d'obtenir une bonne dispersion. Les nanoparticules obtenues sont caractérisées par XRD, spectroscopie Raman, TGA, FT-IR, DLS, SEM et la caractérisation magnétique. En utilisant l'analyse STEM, nous avons constaté que la taille et la forme des nanoparticules pouvaient être contrôlées en faisant varier certains paramètres tels que la température de synthèse, la quantité et la nature des réactifs. En outre, des membranes anodiques poreuses à pores très ordonnés ont été fabriquées avec succès avec une anodisation en plusieurs étapes. Des nanorods de ferrite de cobalt ont été produites par la transformation des nanoparticules de CoFe2O4 à l'aide d'une membrane d’alumine poreuses. L'insertion des nanoparticules de CoF2O4 dans les pores des membranes a été étudiée par le microscope électronique à balayage, et il a été possible de suivre le comportement des nanoparticules de CoFe2O4 dans les pores lors de l'insertion ainsi que lors de la transformation
In the present work, monodisperse cobalt ferrite nanoparticle systems have been explored in regard to their magnetic properties and magnetostrictive effect, as well as for use as a ferrofluid. Nanoparticles have been successfully dispersed in an organic solvent. The surface chemistry of the magnetic nanoparticle proves critical to obtaining a homogeneous and well separated high density dispersion in Hexane. In addition, Oleic acid was used to alter the surface of cobalt ferrite nanoparticles and successfully achieve good dispersion. The obtained nanoparticles are characterized using XRD, Raman spectroscopy, TGA, FT-IR, DLS, SEM, and magnetic investigations. Using STEM analysis, we found that the size and shape of nanoparticles could be controlled by varying certain parameters such as the synthesis temperature, the quantity, and nature of reagents. Furthermore, porous anodic membranes with highly ordered pores were successfully fabricated with multi-steps anodizing. Cobalt ferrite nanorods were produced by a transformation of CoFe2O4 nanoparticles using anodic alumina membrane. The insertion of CoF2O4 nanoparticles into the pores of the AAO membranes was studied with a scanning electron microscope, and it was possible to follow the behavior of CoFe2O4 nanoparticles in the pores during the insertion step as well as the transformation step

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19

Ma, Jun Ping. "Rapid and continuous synthesis of functional nanoparticles on a microfluidic platform". Thesis, University of Macau, 2018. http://umaclib3.umac.mo/record=b3952501.

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Peng, Suili. "Nano/micro particle-based functional composites and applications /". View abstract or full-text, 2007. http://library.ust.hk/cgi/db/thesis.pl?NSNT%202007%20PENG.

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21

Alea, Reyes María Elisa. "Novel ᴫ-Functional Components of Micro- and Nanoparticles for Nanomedicine". Doctoral thesis, Universitat de Barcelona, 2017. http://hdl.handle.net/10803/404880.

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The present thesis is included in the area of Nanomedicine and supramolecular chemistry, focused on the design and preparation of different nano and microtools for delivery, therapy and sensing. Initially, the synthesis and characterization of structures derived from gemini-type pyridinium amphiphiles were reported. They have the ability to play multiple roles such as transfer agent and stabilizer, as well as ionophores, and also are responsible for the preparation, stability, and delivery properties of the gold nanoparticles (AuNPs), which gold core is stabilized by the anions present in the bis-pyridinium salts. The gold nanoparticles synthesized proved stable and to have low polydispersity and showed the ability to incorporate piroxicam. Therefore, the in vitro release of 3·AuNPs and 4·AuNPs at two different pH values (7.4 and 5.5) proves a faster release profile at pH 7.4, indicating their suitability as promising materials for delivery in physiological conditions. On the other hand, this report also includes the synthesis and characterization of porphyrin derivatives as photosensitizers in particular metalloporphyrins and their subsequent incorporation to different vehicles such as gold nanoparticles, microparticles (polysilicon-gold) and gold nanorods for their use in photodynamic therapy, due to their capacity to produce reactive oxygen species after irradiation, inducing the cell death. The successfully functionalization of this vehicles were followed by UV-visible absorption spectroscopy, High-Resolution Transmission Electron Microscopy (HRTEM) or Transmission Electron Microscopy (TEM), Dynamic Light Scattering (DLS), X-ray Photoelectron Spectroscopy (XPS), Thermogravimetric analysis (TGA), Fluorescence Spectroscopy, contact angle measurements and fluorescence microscopy. Additionally, the formation of self-assembled monolayers (SAMs) on polysilicon substrates (wafers and microparticles) was investigated, using different immobilization methodologies (covalent and non-covalent) in order to obtain a functionalization protocol which can be easily repetitive and effective. Firstly, this substrates were functionalized with two groups of compounds (pyridinium and imidazolium salts) used as host in the subsequent incorporation of the Zn(II) porphyrin with a high potential to be used in PDT. The immobilization of the different hosts was following by contact angle, while the presence of the Zn(II) porphyrin was confirmed by fluorescence microscopy. The concentration of the photosensitizer incorporated on the polysilicon microparticles was found in the range of 2.2-2.6 µM. On the other hand, a release study of the incorporated porphyrin during a week was performed, resulting in a very low percentage of the total incorporated porphyrin. This result indicates that a stable interaction is established between the porphyrin and the host on the surface. Finally, we describe the non-covalent functionalization of polysilicon substrates (wafers and microparticles) with gemini-type amphiphilic bipyridinium salts (1·4PF6- 3·4PF6), witch act as host for the subsequent incorporation of the neurotransmitters Dopamine hydrochloride (Dop), Serotonin hydrochloride (Ser), Adrenaline hydrochloride (Adr) and Noradrenaline hydrochloride (Nor), in order to obtain the optimum system potentially suitable for sensors of compounds with electron rich groups. The successfully functionalization of the polysilicon substrates was followed by contact angle measurements. Additionally, fluorescence microscopy was used to detect the complex bis-bipyridinium salt-neurotransmitter in both substrates showed an increase on the fluorescence intensity on the substrates functionalized with the bis- bipyridinium salts and subsequent incorporation of the neurotransmitters respect to the controls. Polysilicon surfaces functionalized with 1·4PF6 and subsequent incorporation of Dop or Ser showed the higher values of fluorescence intensity of 71 and 72%, respectively. In this context the bis-bipyridinium 1·4PF6 and neurotransmitters Dop or Ser were selected to functionalize polysilicon microparticles. 1·4PF6 was neither cytotoxic nor genotoxic to the cell lines studied 3T3/NIH, HepG2 and CaCo-2 at the maximum concentration tested of 500 µg/mL. With our work, we set up the non- covalent functionalization methodology to develop a microsystem potentially useful for drug sensors purposes.
La presente tesis se incluye en el área de Nanomedicina y química supramolecular, enfocada en el diseño y preparación de diferentes sistemas nano y micro estructurados para la liberación, terapia y detección. Inicialmente, fueron sintetizadas y caracterizadas un grupo de moléculas anfifílicas basadas en sales de piridinio tipo gemini, las cuales se caracterizan por desempeñar múltiples funciones, tales como: agente de transferencia y estabilizador, así como ionóforos, además de ser responsables de la preparación y estabilidad de nanopartículas de oro. Las nanopartículas de oro sintetizadas resultaron ser estables y de baja polidispersión, además de ser capaces de incorporar fármacos como piroxicam y liberarlo a pH 7,4 y 5,5, obteniéndose un perfil de liberación más rápido a pH 7,4. Por otro lado, la tesis también describe la preparación de nano y microsistemas para su aplicación en terapia fotodinámica (PDT). La PDT se basa en el uso de moléculas específicas llamadas fotosensibilizadores, que al ser irradiadas, activan el proceso de la muerte celular debido a la formación de radicales libres de oxígeno. La combinación de la utilización de nano y micro vehículos modificadas con un fotosensibilizador resulta un buen objetivo que podría mejorar la terapia antitumoral, disminuyendo los efectos secundarios de la misma. Concretamente, se describe la preparación de nuevos fotosensibilizadores derivados de las porfirinas en particular metaloporfirinas con el fin de ser incorporados en diferentes vehículos como nanopartículas de oro, micropartículas (polisilicio y polisilicio-oro) además de nanohilos de Cobalto-Niquel recubiertos con oro. También se detalla el estudio de la capacidad de los nuevos nano and microsistemas obtenidos, de producir oxígeno singlete como elemento inductor de la apoptosis celular. Estos estudios, demuestran la posibilidad de dichos nanos y microsistemas para ser usados en PDT. Finalmente, micropartículas de polisilicio fueron no covalentemente funcionalizadas con sales de bipiridinio tipo gemini como moléculas ᴫ-aceptoras que actúan como huésped en la subsecuente incorporación de neurotransmisores como moléculas ᴫ-donoras. De esta forma fue posible establecer la metodología de funcionalización no covalente para desarrollar un microsistema potencialmente útil para propósitos de sensores de moléculas con grupos ricos en electrones como es el caso de los neurotransmisores estudiados.

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22

Wang, Wenjing [Verfasser]. "Multivalent adsorption of biological nanoparticles on functional surfaces / Wenjing Wang". Magdeburg : Universitätsbibliothek, 2016. http://d-nb.info/1128726432/34.

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23

Xu, Youyong. "Functional cylindrical polymer brushes and their hybrids with inorganic nanoparticles". kostenfrei, 2008. http://opus.ub.uni-bayreuth.de/volltexte/2009/497/.

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24

Dahl, Jennifer Ann 1976. "Synthesis of functional nanomaterials within a green chemistry context". Thesis, University of Oregon, 2007. http://hdl.handle.net/1794/6131.

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xvii, 183 p. : ill. (some col.) A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number.
In recent years, nanoscience has evolved from a multidisciplinary research concept to a primary scientific frontier. Rapid technological advancements have led to the development of nanoscale device components, advanced sensors, and novel biomimetic materials. However, potential negative impacts of nanomaterials are sometimes overlooked during the discovery phase of research. The implementation of green chemistry principles can enhance nanoscience by maximizing safety and efficiency while minimizing the environmental and societal impacts of nanomaterials. This dissertation introduces the concept of green nanosynthesis, demonstrating the application of green chemistry to the synthesis of nanornaterials. A comprehensive review of the synthesis of metal nanomaterials is presented, demonstrating how individual green chemistry principles can improve traditional synthetic routes as well as guide the design of new materials. Detailed examples of greener syntheses of functionalized gold nanoparticles with core diameters of 2-10 nm are described in subsequent chapters, beginning with a method for functionalizing citrate-stabilized gold nanoparticles that are desirable for advanced applications. Although citrate-stabilized gold nanoparticles can be easily produced from a classic procedure using mild reagents and benign methods, functionalization via ligand exchange is often unsuccessful. It was discovered that an ill-defined layer comprised of citrate and other ligands interferes with functionalization processes. By removing excess citrate in a manner where overall structure and stability is maintained, gold cores produced by this route are readily functionalized by incoming thiols, affording unprecedented control over surface composition and functionality. A direct route to functional nanomaterials using Bunte salt precursors is discussed next, describing the use of easily synthesized shelf-stable alternatives to thiols in the preparation of water-soluble gold nanoparticles. Control of core size and surface chemistry is demonstrated through simple manipulation of reagent ratios, yielding products similar to those produced by traditional direct syntheses which rely on the use of thiols. The use of functionalized nanoparticles as "building blocks" for more complex structures was demonstrated in self-assembly processes. Cationic gold particles were deposited upon DNA scaffolds to create linear arrays. A discussion of the future outlook of green nanosynthesis concludes this work, identifying immediate challenges and long-term goals. This dissertation contains previously published and co-authored materials.
Adviser: James E. Hutchison

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25

Hühn, Dominik [Verfasser] y Wolfgang [Akademischer Betreuer] Parak. "Functional Gold Nanoparticles for Biomedical Applications / Dominik Hühn. Betreuer: Wolfgang Parak". Marburg : Philipps-Universität Marburg, 2014. http://d-nb.info/1051934982/34.

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26

Li, Dan Chemical Sciences &amp Engineering Faculty of Engineering UNSW. "Designing functional magnetic nanoparticles with flame spray pyrolysis for bio-applications". Publisher:University of New South Wales. Chemical Sciences & Engineering, 2009. http://handle.unsw.edu.au/1959.4/43346.

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Magnetic nanoparticles (MNPs) hold great promise in the fields of biology and medicine. The synthesis of functional MNPs with precisely controlled crystallographic, physicochemical, and magnetic properties on a large scale still remains the challenge today. This thesis reports the exploration of liquid-fed flame spray pyrolysis (FSP) in the synthesis of functional MNPs, their surface modifications, and potential bio-applications. Superparamagnetic and ferromagnetic maghemite (γ-Fe2O3) nanoparticles, and silica-coated maghemite (SiO2/γ-Fe2O3) nanocomposites were synthesised using FSP. The size of γ-Fe2O3 was controllable from 6 to 53 nm, with morphology evolving from a disordered near-spherical shape to fully ordered 2-D hexagonal/octagonal platelet. The saturation magnetisation (Ms) increased from 21 to 74 emu/g with increasing particle size, up to 13 nm when Ms approached the bulk γ-Fe2O3 characteristics. In the case of SiO2/γ-Fe2O3, three distinct morphologies, namely the single segregated γ-Fe2O3 core- SiO2 shell, transitional mixed morphologies, and multi γ-Fe2O3 cores embedded in submicron SiO2 shell, were obtained. The core size, composite size, and morphology of γ- Fe2O3 were tunable by varying %SiO2 loading and the use of a quartz tube enclosure during flame synthesis. The magnetic behaviour correlated well with the crystal microstructure. Following the core particle design, protein adsorption-desorption behaviour on FSP-madeMNPs was studied. Bovine serum albumin (BSA) adsorption was found to follow the Langmuir isotherm, with high binding capacities (150−348 mg BSA/g particle) and fast association constants. Electrostatically governed BSA orientations were proposed for different particle-buffer systems. The adsorbed BSA was effectively recovered by pH-shift using K2HPO4. Subsequently, terminal amine, aldehyde, carboxylic, epoxy, mercapto and maleimide functionality were anchored onto the FSP-made γ-Fe2O3 particles. These versatile functional groups led to conjugation of active trypsin. The immobilised trypsin exhibited superior durability with >60% residual activity after one week, and excellent reusability for >5 cycles. The trypsin-conjugated MNPs are promising carriers in proteomics, demonstrating good substrate specificity with equivalent or better sequence coverage compared to free trypsin in insulin and BSA digestion. In another application, a refined silanisation procedure simultaneously reduced γ-Fe2O3 to Fe3O4, and generated thiol enriched surface for matrix metalloproteinase-2 (MMP-2) conjugation. The highly active MMP-2-conjugated MNPs could potentially enhance the interstitial transport of macromolecule/nanoparticles in drug delivery.

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27

Nolan, Mark Gerard. "Novel routes to functional (CVD) films containing nanoparticles and their applications". Thesis, University of Salford, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.420454.

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28

Popov, Anton. "Synthesis of functional nanomaterials by femtosecond laser ablation in liquids". Thesis, Aix-Marseille, 2019. http://www.theses.fr/2019AIXM0065.

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Cette thèse visait à développer des techniques d'ablation au laser et de fragmentation dans des liquides pour la synthèse de nouveaux NPs ayant des fonctionnalités utiles. L’approche de la thèse est axée sur l’élaboration de la technique ablative au laser pour la synthèse de matériaux conventionnels avec des paramètres pour des applications biomédicales sélectionnées, ainsi que sur le développement de cette technique pour la synthèse de nouveaux nanomatériaux destinés à des applications biomédicales. En particulier, il comprend:1. Nous avons élaboré un régime de fragmentation laser fs à partir de colloïdes de Si pour la synthèse de NPs de Si ayant une taille, une cristallinité et un état d'oxydation contrôlables.Nous avons testé un certain nombre d’applications biomédiales particulières de Si Si préparés de cette manière.2. Nous avons développé une technique d'ablation et de fragmentation au laser fs pour fabriquer des noyaux Au NPs et des carottes en Au-Si nus pour SERSapplications. Une approche est basée sur l'ablation au laser de la cible Au dans une solution colloïdale de NP Si.3. Pour la première fois, nous avons synthétisé de nouveaux NP plasmoniques à base de nitrure de titane. Nous avons également montré qu’une étape supplémentaire de fragmentation du laser fs entraînait une diminution de la taille des NP à 5 nm. En outre, nous avons constaté que ces NP ont un très large pic d'extinction dans le proche IR.4. Pour la première fois, nous avons démontré la synthèse de NPs organiques fluorescentes d'un luminophore à émission induite par agrégation spécialement conçu (AIE LP). La luminosité de ces NP a été jugée comparable à celle des points quantiques
This thesis as aimed at the development of techniques of fs laser ablation and fragmentation in liquids for the synthesis of novel NPs having useful functionalities. The approach of the thesis is focused on the elaboration of the laser ablative technique for the synthesis of conventional materials with parameters for selected biomedical applications, as well as the development of this technique for the synthesis of novel nanomaterials for biomedical applications. In particular it includes:1. We elaborated a regime of fs laser fragmentation from Si colloids for the synthesis of Si NPs having controllable size, crystallinity and oxidation state. We tested so-prepared Si NPs a number of particular biomedial applications.2. We elaborated a technique of fs laser ablation and fragmentation to fabricate bare Au NPs and Au-Si core-shells for SERSapplications. One approache is based on laser ablation of Au target in colloidal solution of Si NPs. 3. For the first time we synthesized novel plasmonic NPs based on titanium nitride. We also showed that an additional fs laser fragmentation step leads to the decrease of NPs size to 5 nm. Besides, we found that such NPs have a very broad extinction peak in the near IR.4. For the first time we demonstrated the synthesis of fluorescent organic NPs of specially designed aggregation-induced emission luminophore (AIE LP). The brightness of such NPs was determined to be comparable to that of quantum dots

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29

Dirlam, Philip Thomas. "The Preparation of Functional Surfaces". DigitalCommons@CalPoly, 2011. https://digitalcommons.calpoly.edu/theses/588.

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Diels-Alder chemistry was utilized to manipulate the surface energy of glass substrates in reversible manner. Glass slides and capillaries were functionalized with hydrophobic dieneophiles resulting in a non-wetting surface. A retro Diels-Alder reaction facilitated by the thermal treatment of the surface’s function to cleave the hydrophobic dieneophile and resulted in the fabrication of a hydrophilic surface. Contact angle (CA) measurements were used as preliminary measurements for monitoring the changes in surface energy exhibited during the initial hydrophobic state (CA - 70±3°), after attachment of the dieneophile creating a hydrophobic state (CA - 101±9°) followed by reestablishment of the hydrophilic state (CA - 70±6°) upon cleavage of the Diels-Alder adduct. The treatments developed on flat glass surfaces were transferred to glass capillaries, with effective treatment confirmed by fluid column measurements. Effective flow gating was developed in the capillaries via patterning of the surface with hydrophilic/hydrophobic regions. Finally, attempts to create self-pressurizing capillaries were unsuccessful due to pronounced contact angle hysteresis for the hydrophobic surface treatment. Indium-tin oxide (ITO) substrates were functionalized with successive surface intiated atom transfer radical polymerization (SI-ATRP) and electropolymerization. A novel hybrid styrenic/thiophene monomer (ProDOT-Sty) was synthesized and employed in the polymerization events. This unique monomer and combination of polymerization methods allowed for the templation of electropolymerized poly(3,4-alkyleneoxythiophene) brushes by first creating a poly(styrene) backbone via SI-ATRP. An ITO electrode functionalized with poly(ProDOT-Sty) brushes grafted from the ITO surface via SI-ATRP was analyzed via cyclic voltammetry which clearly indicated the electropolymerization event beginning at approximately +0.7 V vs Fc/Fc+. Photo patterning of the phosphonic acid ATRP initiator immobilized on the ITO surface was undertaken in order to create a surface that would limit growth of the polymer species to a patterned area for facile film brush thickness characterization via atomic force microscopy (AFM) at a later time. This was accomplished via lithography with ultraviolet radiation (UV) and was confirmed via scanning electron microscopy (SEM). A nanohetero structure composed of platinum tipped cadmium selenide seeded, cadium sulfide nanorods (CdSe@CdS-Pt NRs). CdSe quantum dots (QDs) with variable sizes were prepared by adjusting reaction temperatures and times. CdS nanorods were then grown utilizing the CdSe QDs as seeds. Various lengths of the CdSe@CdS NRs were produced that ranged from ~25 nm to ~135 nm. Investigation of the influence of the various synthetic conditions of the nanorod synthesis led to the conclusion that the ratio of CdSe seeds to Cd and S precursors could be manipulated in order to influence the length to which the nanorods grew. Pt tips were attached to an end of the CdSe@CdS nanorods as photocatalytic hydrogen production sites. TEM was utilized to characterize the different types of nanoparticles at each stage of assembly.

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30

Prevo, Brian Geoffrey. "ENGINEERED DEPOSITION OF FUNCTIONAL COATINGS FROM MICRO- AND NANOPARTICLES USING CONVECTIVE ASSEMBLY". NCSU, 2006. http://www.lib.ncsu.edu/theses/available/etd-11202005-150427/.

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The potential technological applications of micro- and nanoparticle coatings necessitate the development of rapid, inexpensive and easily controlled deposition procedures. We have developed a technique for making structured thin films from micro- and nanoparticles by dragging on a substrate a liquid meniscus at constant velocity. The advantages of this technique are improved process speed, efficiency and reduced material consumption relative to standard dip coating techniques. The governing mechanism of the deposition process was found to be convective assembly at high volume fractions. Uniform, large area coatings (square centimeters in area) can be deposited in minutes at rates approaching 100 microns per second from microliters of suspension. Operational ?phase? diagrams were constructed from coating data, relating the coating layer thickness and particle packing symmetry to the process parameters: deposition speed, particle volume fraction, and solvent evaporation rate. Varying these parameters provided the means to control and tune nanocoating structure and properties. We found the most potent parameter to be the deposition speed. The deposition process was well modeled by a simple macroscopic species balance taken around the thin film drying site. We have successfully applied this deposition technique to a wide variety of colloidal systems including: latex and silica microspheres, gold nanoparticles, ferritin proteins, and living yeast cells. Conductive coatings from metal nanoparticles exhibited tunable optical and electronic properties simply by virtue of the adjusting deposition speed. The antireflective (AR) capabilities of silica nanoparticle coatings on glass and silicon substrates can also be facilely tuned using this deposition process. These AR coatings demonstrably improved the photovoltaic efficiency of solar cells. We have also investigated the use of compressed carbon dioxide as a replacement solvent for colloidal coating deposition. We achieved rapid sedimentation of uniform, conformal nanoparticle coatings using liquid and supercritical carbon dioxide (primarily as an antisolvent). These results show potential for fabricating conformal coatings of self cleaning, technologically relevant materials by simple self-assembly techniques.

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31

Lesnyak, Vladimir [Verfasser]. "Colloidal Semiconductor Nanoparticles as Functional Materials : Design, Assembly and Applications / Vladimir Lesnyak". Dresden : Technische Universität Dresden, 2021. http://d-nb.info/1231845910/34.

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32

Dahl, Jennifer Ann. "Synthesis of functional nanomaterials within a green chemistry context /". Connect to title online (Scholars' Bank) Connect to title online (ProQuest), 2007. http://hdl.handle.net/1794/6131.

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Thesis (Ph. D.)--University of Oregon, 2007.
Typescript. Includes vita and abstract. Includes bibliographical references (leaves 158-183). Also available online in Scholars' Bank; and in ProQuest, free to University of Oregon users.

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33

Weerawardene, K. L. Dimuthu M. "Optical and luminescence properties of noble metal nanoparticles". Diss., Kansas State University, 2017. http://hdl.handle.net/2097/38189.

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Doctor of Philosophy
Department of Chemistry
Christine M. Aikens
The remarkable optical and luminescence properties of noble metal nanoparticles (with diameters < 2 nm) attract researchers due to potential applications in biomedicine, photocatalysis, and optoelectronics. Extensive experimental investigations on luminescence properties of thiolate-protected gold and silver nanoclusters during the past decade have failed to unravel their exact photoluminescence mechanism. Herein, density functional and time-dependent density functional theory (DFT and TDDFT) calculations are performed to elucidate electronic-level details of several such systems upon photoexcitation. Multiple excited states are found to be involved in photoemission from Au₂₅(SR)₁₈– nanoclusters, and their energies agree well with experimental emission energies. The Au₁₃ core-based excitations arising due to electrons excited from superatom P orbitals into the lowest two superatom D orbitals are responsible for all of these states. The large Stokes shift is attributed to significant geometrical and electronic structure changes in the excited state. The origin of photoluminescence of Ag₂₅(SR)₁₈– nanoclusters is analogous to their gold counterparts and heteroatom doping of each cluster with silver and gold correspondingly does not affect their luminescence mechanism. Other systems have been examined in this work to determine how widespread these observations are. We observe a very small Stokes shift for Au₃₈(SH)₂₄ that correlates with a relatively rigid structure with small bond length changes in its Au₂₃ core and a large Stokes shift for Au₂₂(SH)₁₈ with a large degree of structural flexibility in its Au₇ core. This suggests a relationship between the Stokes shift of gold−thiolate nanoparticles and their structural flexibility upon photoexcitation. The effect of ligands on the geometric structure and optical properties of the Au₂₀(SR)₁₆ nanocluster is explored. Comparison of the relative stability and optical absorption spectra suggests that this system prefers the [Au₇(Au₈SR₈)(Au₃SR₄)(AuSR₂)₂] structure regardless of whether aliphatic or aromatic ligands are employed. The real-time (RT) TDDFT method is rapidly gaining prominence as an alternative approach to capture optical properties of molecular systems. A systematic benchmark study is performed to demonstrate the consistency of linear-response (LR) and RT-TDDFT methods for calculating the optical absorption spectra of a variety of bare gold and silver nanoparticles with different sizes and shapes.

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34

Dalzon, Bastien. "Etude des réponses des macrophages aux nanoparticules d'oxydes métalliques par une combinaison d'approches protéomiques et ciblées". Thesis, Université Grenoble Alpes (ComUE), 2018. http://www.theses.fr/2018GREAV013.

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De par leurs propriétés, les nanoparticules suscitent des sentiments très contrastés. Elles sont considérées comme prometteuses dans de nombreux champs d’application, notamment dans le domaine médical. Beaucoup d’approches thérapeutiques utilisent aujourd’hui des nanoparticules comme par exemple, pour soigner les cancers. Cependant, les nanoparticules sont également vues comme une source potentielle de danger pour la santé humaine, en particulier lorsque l’on considère les crises sanitaires historiques liées à l’inhalation répétée de particules de silice cristalline ou de fibres d’amiante qui provoque de graves maladies telles que la silicose et l’asbestose. Les macrophages alvéolaires sont aujourd’hui connus pour jouer un rôle central dans l’évolution de ces deux maladies. Nous nous sommes donc intéressés aux aspects à la fois positifs et négatifs des nanoparticules. Dans un premier projet, afin de répondre à un problème de santé public, nous avons étudié l’effet de différents types de nanoparticules de silices amorphes sur la dérégulation des fonctionnalités principales des macrophages. Les principaux tests effectués ont montré un effet important sur les macrophages lorsque les nanoparticules de silice sont à des concentrations subtoxiques (dose létale 20), en revanche nous avons seulement observé un léger effet lorsque les macrophages sont exposés à des doses journalières équivalentes aux normes d’expositions imposées. Dans un deuxième projet, nous avons développé une stratégie de cheval de Troie dans laquelle des macrophages différenciés in vitro servent à véhiculer une grande quantité de nanoparticules d’oxyde de fer photoactivables au niveau des sites tumoraux. Cela afin d’améliorer les radiothérapies actuelles. Les premiers tests ont démontré que le Ferinject® était peu toxique pour les macrophages même à de fortes concentrations. Ensuite, les expérimentations pré-cliniques effectuées sur la souris ont validé notre concept puisque les macrophages injectés dans la circulation sanguine sont capables de migrer vers la tumeur
Because of their properties, nanoparticles have generated opposed views. They are perceived as promising in many fields of application, particularly in medicine. Nanoparticles are currently used in many therapeutic approaches such as cancer therapy. However, in view of past health crises related to the repeated inhalation of crystalline silica particles and asbestos fibers, nanoparticles are also viewed as a source of potential risks for human health. Alveolar macrophages are now known to play a major role in the evolution of these two diseases. We thus chose to study both the positive and negative aspects of nanoparticles. In order to address a public health issue, our first project focused on the effect of different types of amorphous silica nanoparticles on the disruption of the main functionalities of macrophages. The main tests performed showed a significant effect on macrophages when amorphous silica nanoparticles were tested at subtoxic concentrations (lethal dose 20). However, we only observed minor effects when macrophages were exposed to a daily dose equivalent to the safety standards. For the second project we developed a Trojan horse strategy using macrophages to bring a significant quantity of photoactivatable nanoparticles to the tumor site so as to improve current radiotherapies. The first assays proved that Ferinject® was not toxic to macrophages even at high concentrations. Then, the pre-clinical experiments performed on mice validated our strategy because macrophages injected into the bloodstream were able to migrate toward the tumor

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35

Huang, Xing. "Structure and Catalytic Properties of Ultra-Small Ceria Nanoparticles". UKnowledge, 2014. http://uknowledge.uky.edu/cme_etds/25.

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Cerium dioxide (ceria) is an excellent catalytic material due to its ability to both facilitate oxidation/reduction reactions as well as store/release oxygen as an oxygen buffer. The traditional approach to assess and improve ceria's catalytic behavior focuses on how efficiently O-vacancies can be generated and/or annihilated within the material, and how to extend established understandings of "bulk" ceria to further explain the greatly enhanced catalytic behavior of ultra-small ceria nanoparticles (uCNPs) with sizes less than 10 nm. Here, using density functional theory (DFT) calculations, we reexamine the atomic and electronic structures of uCNPs, especially their surface configurations. A unique picture dissimilar to the traditional point of view emerges from these calculations for the surface structure of uCNPs. uCNPs similar to those obtained by experimental synthesis and applied in catalytic environments exhibit core-shell like structures overall, with under-stoichiometric, reduced CNP "cores" and over-stoichiometric, oxidized surface "shell" constituted by various surface functional groups, e.g.,-Ox and/or -OH surface groups. Therefore, their catalytic behavior is dominated by surface chemistry rather than O-vacancies. Based on this finding, reaction pathways of two prevalent catalytic reactions, namely CO oxidation and the water-gas shift reaction over uCNPs are systematically investigated. Combined, these results demonstrate an alternative understanding of the surface structure of uCNPs, and provide new avenues to explore and enhance their catalytic behavior, which is likely applicable to other transition metal oxide nanoparticles with multivalent ions and very small sizes.

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36

Maye, Mathew M. "Design, synthesis, and assembly of functional nanoarchitectures". Online access via UMI:, 2005.

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37

Amorín, Ferré Laura. "New functional ligands for the preparation of photoactive nanoparticle‐based materials". Doctoral thesis, Universitat Autònoma de Barcelona, 2014. http://hdl.handle.net/10803/315652.

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La nanociència i la nanotecnologia han esdevingut les noves disciplines del nou mil·leni. Els processos desenvolupats per molts científics arreu del món, com per exemple el disseny, la fabricació i la manipulació a escala nanomètrica, han revolucionat la física, la química, la biologia i la tecnologia. La present tesi doctoral s'emmarca dins aquests camps. Més concretament, s'han dissenyat, sintetitzat i caracteritzat diferents lligands orgànics per (i) introduir-los en nanopartícul·les de polímers de coordinació (CPPs) i estudiar processos d'alliberament de fàrmacs, o (ii) estabilitzar nanopartícul·les semiconductores, o quantum dots (QDs), per enllaçarlos ordenada i controladament. Les CPPs són partícules metal·lorgàniques capaces de nanoestructurar-se que s’han proposat com a potencials materials en el camp de la medicina, com a novedosos agents portadors de fàrmacs o d’agents de contrast. Encara que s'ha demostrat la seva capacitat portadora i la seva eficiència d'alliberament, a dia d'avui no existeix cap estudi del mecanisme d'alliberament dels compostos encapsulats. És per això que s'ha proposat com a primer objectiu d'aquesta tesi doctoral l'estudi racional dels mecanismes implicats quan un compost és alliberat per aquests sistemes. Així, s'han dissenyat i sintetitzat diferents compostos orgànics fluorescents per introduir-los dins de les nanopartícul·les de polímers de coordinació, atrapades físicament i enllaçades covalentment a la matriu polimèrica, i estudiar-ne els mecanismes d'alliberament mitjançant mesures de fluorescència. L'anàlisi dels resultats obtinguts demostra una ràpida difusió del fàrmac (durant les primeres hores) i, només després d’un cert temps, un procés de degradació amb una cinètica més lenta. Aquest treball demostra que futurs sistemes portadors de fàrmacs poden ser racionalment dissenyats depenent de la cinètica d'alliberament desitjada en cada cas particular. Per altra banda, els QDs són nanopartícules col·loïdals cristal·lines semiconductores amb propietats opto-electròniques extraordinàries i fàcilment modulables variant-ne la composició, la mida o la forma que s'han aplicat en la construcció de light emitting diodes (LEDs) i de cel·les solars. La present tesi doctoral té per objectiu la construcció de nous cables fotònics d’escala nanomètrica basats en QDs on processos de transferència energètica entre QDs conduiran l’energia lumínica unidireccionalment. L'estratègia dissenyada es basa en la reacció de cicloaddició alquí-azida promoguda per tensió anular (Strain-Promoted Alkyne-Azide Cycloadditon, SPAAC) entre ambdós compostos que han estat prèviament ancorats a la superfície de QDs amb propietats òptiques diferents. Amb aquest objectiu, s'han sintetitzat i caracteritzat diferents estabilitzants orgànics amb grups funcionals lliures (ciclooctí i azida) que són capaços de reaccionar selectivament entre ells. Els resultats obtinguts han demostrat la viabilitat de l'estratègia plantejada ja que s'han obtingut agregats discrets de diferents quantum dots amb altes eficiències de transferència d'energia.
Nanoscience and nanotechnology are the novel disciplines emerged at the new millennium. The abilities for designing, fabricating and applying nanostructures and nanomaterials have revolutionized physics, chemistry, technology and biology. The present PhD thesis is focused on these fields. In particular, the design, synthesis and characterization of different organic ligands have been the main goal of the current work for (i) introducing them into coordination polymer particles (CPPs) and studying drug delivery processes, or (ii) stabilizing semiconductor nanoparticles, or quantum dots (QDs), and linking them in an ordered and controlled manner. CPPs are metaloorganic nanoparticles that have been proposed as potential drug carriers or contrast agents in the field of medicine. Even though many scientists have demonstrated CPPs are efficient carriers and delivers, to date no rational study exists for the drug delivery mechanisms. In view of this, the main objective of the first project of this PhD thesis is to rationally establish the release mechanisms of a drug from those systems. In this way, different fluorescent organic ligands have been designed, synthesized and characterized for introducing them into the CPPs and studying the delivery mechanisms by means of fluorescence measurements. Analysis of the obtained results demonstrates a fast diffusion of the drug (during the first hours of release) and slower degradation processes. By selectively monitoring the release kinetics of those fluorophores, we have not only demonstrated the occurrence of such mechanisms, but also assessed for the first time their individual efficiencies in view of the rational design of future systems with tailored drug delivery profiles. On the other hand, QDs are crystalline and colloidal semiconductor nanoparticles with unique optoelectronic properties, which can be modulated by finely tuning their composition, size or shape. QDs have been applied in the preparation of light emitting diodes (LEDs) and of solar cells. The present PhD thesis aims to the formation of new QD-based photonic nanowires for the efficient and unidirectional transport of excitation energy between the different QDs. Our approach relies on the functionalization of the semiconductor nanoparticles with ligands bearing azide and cyclooctyne groups, which can undergo Cu-free, strain-promoted azide-alkyne cycloaddition (SPAAC) under standard ambient conditions. As a first step towards the fabrication of future nanophotonic devices, we aimed herein to demonstrate the viability and potential of this synthetic strategy to conduct the controlled assembly of quantum dots. The obtained results demonstrated SPAAC-induced formation of QD heteroaggregates, which showed high energy transfer efficiences. This work opens up the door for future application of this methodology to the construction of 1D assemblies of well-ordered QDs.

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38

Ghosh, Suvojit. "Self-assembly of magnetic nanoparticles: A tool for building at the nanoscale". Diss., Virginia Tech, 2014. http://hdl.handle.net/10919/54539.

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Nanoparticles can be used as building blocks of materials. Properties of such materials depend on the organization of the constituent particles. Thus, control over particle organization enables control over material properties. However, robust and scalable methods for arranging nanoparticles are still lacking. This dissertation explores the use of an externally applied magnetic field to organize magnetic nanoparticles into microstructures of desired shape. It extends to proofs of concept towards applications in material design and tissue engineering. First, external control over dipolar self-assembly of magnetic nanoparticles (MNPs) in a liquid dispersion is investigated experimentally. Scaling laws are derived to explain experimental observations, correlating process control variables to microstructure morphology. Implications of morphology on magnetic properties of such structures are then explored computationally. Specifically, a method is proposed wherein superparamangetic nanoparticles, having no residual magnetization, can be organized into anisotropic structures with remanence. Another application explores the use of magnetic forces in organizing human cells into three-dimensional (3D) structures of desired shape and size. When magnetized cells are held in place for several days, they are seen to form inter-cellular contacts and organize themselves into tight clusters. This provides a method for 3D tissue culture without the use of artificial scaffolding materials. Finally, a method to pattern heterogeneities in the stiffness of an elastomer is developed. This makes use of selective inhibition of the catalyst of crosslinking reactions by magnetite nanoparticles. The last chapter discusses future possibilities.
Ph. D.

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39

Okada, Hiroshi. "Development of Functional Materials Based on Organic-Inorganic Hybrids". 京都大学 (Kyoto University), 2014. http://hdl.handle.net/2433/188609.

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40

Sette, Daniele. "Functional printing : from the study of printed layers to the prototyping of flexible devices". Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENI065/document.

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Depuis les années 2000, l'impression fonctionnelle connait un grand succès pour la fabrication de composants électroniques. Elle se positionne de manière complémentaire par rapport aux technologies du silicium et vise principalement les marchés de l'électronique grande surface (écrans, panneaux photovoltaïques) et de l'électronique flexible (RFID, capteurs, textiles intelligents). Dans ce travail, des couches d'argent imprimées par jet d'encre ont été caractérisées en fonction des conditions d'impression et de recuit. L'évolution de leur microstructure, de leurs propriétés électriques et mécaniques a été étudiée. Dans ce cadre, des méthodes expérimentales ont été développées et validées par la bonne corrélation entre les mesures et les modèles. La maîtrise des propriétés de ces couches et l'optimisation de leur procédé de fabrication nous ont conduits à concevoir, fabriquer et caractériser plusieurs composants flexibles: un filtre passe bande centré à 17 GHz sur un substrat polyimide, un micro-capteur de vide fonctionnant sur le principe de Pirani et un bouton-poussoir d'épaisseur inférieure à 250 µm pour des claviers souples. Enfin, des condensateurs RF ont été réalisés par la superposition de couches imprimées diélectriques (BaSrTi) et conductrices (Ag). Les performances des prototypes réalisés sont proches de l'état de l'art et ouvrent la voie à de nouvelles applications pour les technologies d'impression. Cette étude démontre le potentiel des couches d'argent imprimées par jet d'encre pour la fabrication de dispositifs flexibles
In the last decade, functional printing has gained a large interest for the manufacturing of electronic components. It stands aside to silicon technologies and specifically targets markets of large area devices (screens, photovoltaics) and flexible electronics (RFID antennas, sensors, smart textiles). In this work, inkjet printed silver layers are characterized depending on the printing conditions and the required post-printing annealing. The evolution of their microstructure, electrical and mechanical properties is investigated as a function of the annealing temperature. The correlation of the measurements with theoretical models supports the experimental methods that were developed. The knowledge of the printed silver layers assets and the optimization of the printing process lead to the design, fabrication and characterization of flexible electronics devices: a 17 GHz band-pass filter printed on polyimide, a flexible vacuum micro-sensor working on the Pirani principle, and a 250 µm thick membrane switch for keyboards. Finally, all printed RF capacitors were realized by stacking Barium Strontium Titanate (dielectric) and silver printed layers. These prototypes exhibit performances near the state-of-the-art and suggest new opportunities for printing technologies. This thesis offers a thorough study of inkjet printed silver layers and assess their potential for the manufacturing of flexible devices

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41

Keller, Dominic Charles André [Verfasser] y G. [Akademischer Betreuer] Delaittre. "Functional Core-Shell Nanoparticles for Enzyme Immobilization / Dominic Charles André Keller ; Betreuer: G. Delaittre". Karlsruhe : KIT-Bibliothek, 2017. http://d-nb.info/1139360396/34.

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42

Manson, Joanne. "PLGA films containing poly(ethylene glycol) functional gold nanoparticles for potential drug delivery applications". Thesis, University of Ulster, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.557399.

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In this study novel composites comprising poly(ethylene glycol) functionalised gold nanoparticles (PEG-AuNP) dispersed within a poy(DL-Iactic-co-glycolic) (PLGA) film were produced via a solvent-casting technique and their effect on the degradation of PLGA investigated. In addition to the release profile of AuNPs during degradation was studied. The production of PLGA films containing PEG-AuNPs is a first step proof-of-principle concept for the aim of producing a composite capable of both targeted and sustained drug delivery. PLGA films were produced via solvent-casting using a number of molecular weight 50:50 PLGA polymers and three commonly reported solvents, namely dichloromethane, chloroform and acetone. The effect of molecular weight and solvent choice was investigated in regard to drying time required and subsequent residual solvent levels. Analysis reported a drying time of 14 days at 40°C, 400 mbar, with dichloromethane displaying the lowest residual solvent content after drying, PLGA 3A (0.58 dL/g) was found to be the most robust sample in terms of ease of handing. The mould material is one of the most important features of solvent-casting in terms of removing the sample after drying, to this end it was demonstrated that glass petri dishes pre-coated with RainX proved ideal. PEG functionalisation of the AuNP surface allows for successful drying and re- dispersion in a range of media (PBS, H20, PBS-BSA, and DCM). A PEG capping density of 16.8 μg/mL was found from UV-Vis, TGA and DLS to be the most suitable for successful incorporation into PLGA films via solvent-casting. A range of weight percentages of PEG-AuNPs were successfully incorporated into PLGA films namely, 0.2, 0.4, 0.6, 0.8, 1 and 2 wt%. The AuNP release profile of PLGA containing 1 and 2 wt% PEG functionalised AuNPs was studied using ICP-MS during degradation. Unfunctionalised AuNPs could not be successfully incorporated in PLGA films due to irreversible aggregation after drying. The incorporation of PEG-AuNPs into PLGA films was found to aid in the drying process and resulted in reduced levels of residual solvent. The addition of 1 and 2 wt% PEG functionalised AuNPs was found to increase the PLGA degradation time from 39 to 58 days. Release of PEG-AuNPs from PLGA films during degradation was investigated using ICP-MS and appeared to follow a relatively sustained release profile for both 1 and 2 wt% PEG-AuNPs over the 58 day degradation timeframe.

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43

Park, Kyoung-Won. "Solar-driven overall water splitting on CoO nanoparticles : first-principles density functional theory studies". Thesis, Massachusetts Institute of Technology, 2018. http://hdl.handle.net/1721.1/117802.

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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Materials Science and Engineering, 2018.
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged student-submitted from PDF version of thesis.
Includes bibliographical references (pages 143-157).
Photoelectrochemical (PEC) water splitting has been suggested as a promising techinique for large-scale hydrogen fuel production. In particular, spontaneous photocatalytic overall water splitting on self-standing particles in water without external driving potential has been highlighted as a clean and economical energy generation method for the future. Among various photocatalytic materials, some cobalt-based materials including CoP, Co₂P, Co(OH)₂, CoO, have attained major interest because they exhibit improved catalytic activity for hydrogen evolution in the form of nanoparticles, unlike most cobalt-based materials which have been assessed as water oxidizing catalysts in the past decade. CoO nanoparticles have been observed to photocatalytically split water into H₂ and O₂ at room temperature without an externally applied potential or co-catalyst, with high photo-catalytic efficiency (solar-to-hydrogen efficiency of ~5%) which hits the record among single-material self-standing photocatalysts. The photocatalytic activity of CoO nanoparticles was experimentally shown to stem from the optimal conduction and valence band edge positions (Ec and Ev) relative to water reduction and oxidation potential levels (H+/H₂ and H₂O/O₂), such that the Ec and EV span the water redox potentials. The overall water splitting is not expected from CoO micropowder or bulk CoO because they have band edges far below the H+/H2 level, which are not optimal for overall water splitting. However, the origin of the shift in the band edges due to decrease in particle size (from bulk or micropowder to nanoparticle) was unknown. Moreover, the mechanism by which H₂ and O₂ simultaneously and spontaneously evolve on the nanoparticles, as well as how the CoO nanoparticles could exhibit a high photocatalytic efficiency even without a co-catalyst or an external driving potential have remained unanswered. In this work, we use first-principles density functional theory (DFT) calculations to explore thermodynamically stable surface configurations of CoO in an aqueous environment in which photocatalytic water splitting occurs. We also calculate the Ec and Ev of CoO surfaces relative to water redox potentials, showing that the band edge positions are sensitive to surface chemistry which is determined by surface orientation, adsorbates, and stoichiometry, and thus growth conditions and operating environment. In particular, we predict that CoO nanoparticles have fully hydroxylated CoO(111) facets (OH*-CoO(111)), with band edges spanning the water redox potentials, while larger CoO particles (such as CoO micropowders) have a full monolayer of hydrogen on the CoO(111) facets, with a band alignment that favors water oxidation but not water reduction. From these calculations, we demonstrate that explicit inclusion of liquid water is crucial for accurately predicting the band edge positions, and thus photocatalytic behavior of CoO in an aqueous solution. In order to find the origin of the high efficiency and spontaneous overall water splitting without an external bias or a co-catalyst, we also elucidate the mechanisms for charge separation and H₂ and O₂ evolution on CoO nanoparticles under illumination in an aqueous solution. We demonstrate that electrons are driven to CoO(100) facets and holes are driven to OH*-CoO(111) facets as a result of a built-in potential arising from the very different potential levels of the two facets. We show that H₂ evolution preferentially occurs on the CoO(100) facets, while O2 evolves on the OH*-CoO(111) surfaces, based on our new criteria. Importantly, we suggest that the conventional criterion for determining the feasibility of H₂ or O₂ generation from water splitting - i.e., EC < H+/H₂ level or Ev > H₂O/O₂ level - is insufficient. Instead, we suggest that a more appropriate set of criteria is whether the photo-excited electrons and holes have sufficient energy to overcome the kinetic barrier for the H₂ and O₂ evolution reaction, respectively, on the relevant surface facet. This work explains why and how photocatalytic overall water splitting has been observed only on CoO nanoparticles. Our understanding of the overall water splitting mechanism on CoO nanoparticles provides a general explanation of experimentally observed overall water splitting phenomena on a variety of self-standing photocatalysts as well as a new approach for screening novel photocatalytic materials for efficient water splitting and other reactions.
by Kyoung-Won Park.
Ph. D.

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44

Baker, James Stewart Jr. "Synthesis of Functional Vinylbenzocyclobutenes for Use as Crosslinkers in the Preparation of Amphiphilic Nanoparticles". University of Akron / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=akron1321304647.

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45

Chowdhury, Afsar. "Synthesis of Functional Stabilisers for High Volume Fraction Metal Nanoparticles by Controlled Radical Polymerisation". Thesis, University of Manchester, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.525278.

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46

Kayandan, Sanem. "Synthesis and Characterization of Poly(lactide) Functional Oligomers and Block Copolymers". Thesis, Virginia Tech, 2013. http://hdl.handle.net/10919/49592.

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Amphiphilic block copolymers consisting of poly(ethylene oxide) and poly(lactide) have great potential for formulating drug delivery systems. Our approach was to synthesize poly(ethylene oxide-b-D,L-lactide), (PEO-b-PDLLA), block copolymers with controlled molecular weights and good functionality on the poly(ethylene oxide) end for the design of potential core-shell delivery vehicles for HIV drugs. PEO-b-PDLLA block copolymer was used as a polymeric nanocarrier to encapsulate the HIV protease inhibitor, Ritonavir, within magnetite nanoparticles. Well-defined multifunctional polymeric nanoparticles with controlled sizes and size distributions were fabricated by rapid nanoprecipitation using blends of the PEO-b-PDLLA block copolymer with poly(L-lactide), (PLLA) homopolymer. Heterobifunctional PEO oligomers were directly prepared by initiating ethylene oxide with functional alcohols bearing vinylsilane, vinylether and maleimide moieties to provide appropriate end groups for conjugating targeting ligands. The polyethers with narrow molecular weight distributions were utilized as macroinitiators for the synthesis of poly(lactide) block. Heterobifunctional diblock copolymers possessing carboxylic acids were prepared from ene-thiol addition reaction of mercaptoacetic acid across the vinyl group on the PEO end, while preserving the hydroxyl functionality on the other end. Additionally, PDLLAs bearing maleimide functionality with controlled molecular weights were synthesized using maleimide functional initiator. End group modification was performed via Michael addition using cysteamine hydrochloride to introduce an amino group over the vinyl bond. The resulting carboxylic acid functional PEO-b-PDLLA diblock copolymers, and amino functional PDLLAs are potential biocompatible polymers that can be utilized to encapsulate an array of bioactive molecules, targeting ligands.

Master of Science

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47

Chan, Chi Fai. "Multi-functional upconversion nanoparticles for in vivo imaging, in vivo tumor suppression and photodynamic therapy". HKBU Institutional Repository, 2016. https://repository.hkbu.edu.hk/etd_oa/272.

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Upconversion nanoparticles (UCNPs) have been utilized for biological applications. Unlike conventional linear excitation molecules, UCNPs are excited by 980nm and emit photon in visible and near infrared region. The unique photophysical property offers superior penetration depth and lower photo-cytotoxicity. With the aid of various vectors such as target-specific peptides and photosensitizers, the UCNPs can precisely interact selectively with designated proteins (Cyclin D1 and Polo-like Kinase 1) and cancer cells so as to achieve theranostic effect. This thesis illustrated the upconversion mechanism and anti-cancer effect by UCNPs conjugated with peptides. Two research studies focus on Cyclin D1 or Polo-like kinase 1 (Plk1) specific peptides coated UCNPs function as key cell cycle inhibitors, in vitro imaging agent and in vivo tumor suppressor. Apart from inorganic nanomaterials, graphitic phase carbon nitride (g-C3N4) nanoparticles coupled with porphyrin moieties act as cancer directional photodynamic therapy agents was also described in the aspects of detailed photophysical measurements and in vitro theranostic studies.

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48

Ibáñez, Sabaté Maria. "Functional Nanomaterials from the Bottom-up Assembly of Colloidal Nanoparticles. A Strategy Towards Efficient Thermoelectrics". Doctoral thesis, Universitat de Barcelona, 2013. http://hdl.handle.net/10803/307536.

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The work developed during this PhD has embraced several topics that I divide in three blocks. Each block contains two chapters in this dissertation. Additionally, a general introduction of the different topics is provided (Chapter 1). The first block corresponds to the study of colloidal synthetic routes to produce functional nanoparticles (Chapter 2 and 3). In the second block the developed nanoparticles are used to produce bulk nanostructured materials. The functional properties of the nanomaterials are also characterized in this second block. As the paradigmatic application for such bottom-up assembled nanostructured materials I considered thermoelectricity (Chapter 4 and 5). In the last block, I go one step beyond and design and prepare multiphase nanoparticles as building blocks for the bottom up production of nanocomposites with improved thermoelectric performance (Chapter 6 and 7).
El treball desenvolupat durant aquesta tesi doctoral engloba diverses temàtiques que s’han dividit en tres blocs. Cada bloc conté dos capítols. A més a més, com a Capítol 1 s’ha inclòs una introducció general de cadascuna de les temàtiques tractades. En el primer bloc, Capítols 2 i 3, s’estudien diferents síntesis col·loïdals per produir nanopartícules funcionals. En el segon bloc, Capítols 4 i 5, les nanopartícules desenvolupades s'utilitzen per produir materials nanoestructurats en bulk a partir del seu assemblatge. Les propietats funcionals d’aquests nanomaterials es caracteritzen també en aquest segon bloc. Com a aplicació paradigmàtica s’ha considerat la termoelectricitat. En l'últim bloc, Capítols 6 i 7, es va un pas més enllà i es dissenyen nanopartícules heterogènies com blocs de construcció per a la producció de nanocompostos amb millor rendiment termoelèctic.

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Bastos, Arrieta Julio. "Bifunctional nanocomposites: surface modification of reactive matrices with functional metal nanoparticles by intermatrix synthesis technique". Doctoral thesis, Universitat Autònoma de Barcelona, 2014. http://hdl.handle.net/10803/285551.

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En aquesta Tesi Doctoral s'ha desenvolupat la tècnica de Síntesi intermatricial (IMS), com a una metodologia factible per la modificació de matrius reactives amb nanopartícules (NPs) basada en les propietats d'intercanvi iònic de la superfície que es vol modificar; com ara: resines intercanviadores iòniques i la innovació en la modificació de nanofilms polimèrics funcionalitzats, nanotubs de carboni (CNTs) i nanodiamantes (NDs). L’efecte dels materials nanoestructutrats sobre el medi ambient és un dels temes més importants a la tecnologia en els darrers anys. A causa del seu alt grau de desenvolupament, producció, difusió i aplicació, les majors preocupacions associades als Nanomaterials (NMs) inclouen: a) l'elevada reactivitat i toxicitat de molts NMs en comparació dels seus anàlegs macroscòpics, b) l'absència de tècniques analítiques òptimes per a la seva determinació en el medi ambient i c) l'absència d'una legislació efectiva que regularitzi els nivells permesos de diversos NMs en sòl, aigua i aire. Per això és primordial la seguretat i estabilitat dels NMs a través de la seva incorporació en els Nanocomposites bifuncionals (BFNCs) La bifuncionalitat dels BFNCs és determinada per les propietats pròpies de la matriu en la qual les NPs metàl·liques (MNPs) són sintetitzades (per exemple polímers d'intercanvi iònic) i per les propietats respectives de les MNPs (magnetisme, activitat bactericida, nanocatlizadores). La modificació superficial de les matrius reactives amb MNPs es porta a terme a través de la IMS acoblada a l'Efecte d'exclusió de Donnan (DEE). D'aquesta manera, els BFNCs preparats amb valor afegit són caracteritzats, les seves propietats són avaluades i es comprova l'estabilitat i la distribució favorable de les MNPs principalment en la superfície dels BFNCs. La IMS inclou diferents possibilitats per a la preparació de MNPs i BFNCs. En una primera etapa es realitza un intercanvi iònic sobre la matriu per fixar els precursors de les NPs. Posteriorment la IMS pot incloure: a) Reducció dels ions a l'utilitzar un agent reductor com NaBH4 o b) precipitació de NMs com quantum dots (QDs) o òxids metàl·lics a l'afegir el contraió respectiu. Sigui quina sigui la ruta que s'empri, els grups funcionals d'intercanvi iònic propis de la matriu són regenerats; de manera que els cicles de IMS poden repetir-se per augmentar el gruix de les MNPs o bé per produir MNPs bimetàl·liques tipus core-shell. Una versió estesa de la IMS és presentada a l'utilitzar el desplaçament galvànic com a precursor per Au- MNPs i AgAu-MNPs a matrius catiòniques, utilitzant MNPs sintetitzades inicialment com nanoplantilles per a la cristal·lització de les noves MNPs mono- o bi- metàl·liques. Un avantatge molt important que aporta la tècnica IMS és la seva gran versatilitat, possibilitant la síntesi de BFNCs amb les propietats desitjades per a les diferents aplicacions: activitat bactericida, magnetisme, catàlisi heterogènia i electroquímica, entre d'altres.
En esta Tesis Doctoral se ha desarrollado la técnica de Síntesis Intermatricial (IMS), como una metodología factible para la modificación de matrices reactivas con Nanoparticulas(NPs) basada en las propiedades de intercambio iónico de la superficie que se desea modificar; tales como: como resinas intercambiadoras iónicas y la innovación en la modificación de nanofilms poliméricos funcionalizados, nanotubos de carbono (CNTs) y nanodiamantes (NDs). El efecto de los materiales nanoestructurados sobre el medio ambiente es uno de los temas más importantes de la tecnología en los últimos años. Dado su alto grado de desarrollo, producción, difusión y aplicación, las mayores preocupaciones asociadas a los Nanomateriales (NMs) incluyen: a) la elevada reactividad y toxicidad de muchos NMs en comparación con sus análogos macroscópicos, b) la ausencia de técnicas analíticas adecuadas para su determinación en el medio ambiente y c) la ausencia de una legislación efectiva que regularice los niveles permitidos de varios NMs en suelo, agua y aire. Por ello es primordial la seguridad y estabilidad de los NMs a través de su incorporación en los Nanocomposites Bifuncionales (BFNCs) La bifuncionalidad de los BFNCs es determinada por las propiedades propias de la matriz en la que las NPs metálicas (MNPs) son sintetizadas (por ejemplo polímeros de intercambio iónicos) y por las propiedades respectivas de las MNPs (magnetismo, actividad bactericida, nanocatlizadores). La modificación superficial de las matrices reactivas con las MNPs se lleva a cabo a través de la IMS acoplada al Efecto de Exclusión de Donnan (DEE). De esta manera, los BFNCs preparados con valor añadido son caracterizados, sus propiedades son evaluadas y se comprueba la estabilidad y la distribución favorable de las MNPs principalmente en la superficie de los BFNCs. La IMS incluye diferentes posibilidades para la preparación de MNPs en BFNCs. En una primera etapa se realiza un intercambio iónico sobre la matriz para fijar los precursores de las NPs. Posteriormente la IMS puede incluir: a) Reducción de los iones al utilizar un agente reductor como NaBH4 o b) precipitación de NMs como quantum dots (QDs) u óxidos metálicos al agregar el contraión respectivo. Sea cual sea la ruta que se siga, los grupos funcionales de intercambio iónico propios de la matriz son regenerados; por lo que los ciclos de IMS pueden repetirse para aumentar el grosor de las MNPs o bien para producir MNPs bimetálicas tipo core-shell. Una versión extendida de la IMS es presentada al utilizar el desplazamiento galvánico como precursor para Au- MNPs y AgAu-MNPs en matrices catiónicas, utilizando MNPs sintetizadas inicialmente como nanoplantillas para la cristalización de las nuevas MNPs mono o bimetálicas. Una ventaja muy importante que aporta la técnica IMS es su gran versatilidad, posibilitando la síntesis de BFNCs con las propiedades deseadas para las diferentes aplicaciones: actividad bactericida, magnetismo, catálisis heterogénea y electroquímica, entre otras.
In this Doctoral Thesis, the Intermatrix Synthesis (IMS) technique has been described as a feasible methodology for the modification of reactive matrices with Nanoparticles (NPs), which is based on the ion exchange properties of the NPs supporting surface, such as ion exchange resins and the innovation of the application of IMS on polymeric nanofilms, carbon nanotubes (CNTs) and nanodiamonds(NDs). The effects of nanostructured materials on the environment are one of the most important issues of technology in recent years. Given their high level of development, production, dissemination and application, the main concerns associated with nanomaterials (NMs) include: a) the high reactivity and toxicity of many NMs compared to their macroscopic analogues, b) the lack of appropriate analytical techniques for their determination in environment and c) the absence of effective legislation to regularize the convenient levels of various NMs in soil, water and air. Therefore, it is a must to ensure the security and stability of NMs through its incorporation into the Bifunctional Nanocomposites (BFNCs) The bifunctionality of BFNCs is determined by the specific properties of the matrix in which the metal NPs (MNPs) are synthesized (for example by ion exchange polymers) and by the respective properties of the MNPs (magnetism, bactericidal, nanocatlizadores). Surface modification of reactive matrices with MNPs is conducted through the IMS coupled to Donnan exclusion effect (DEE). Thus, the added value BFNCs prepared are characterized, their properties are evaluated and stability and the favourable distribution of the MNPs mainly on the surface of BFNCs is verified. The IMS includes different possibilities for the preparation of MNPs on BFNCs. In the first stage ion exchange is performed on the matrix to attach the NPs precursors. Subsequently, the IMS includes: a) Reduction of ions by using a reducing agent such as NaBH4 or b) precipitation of NMs as quantum dots (QDs) or metal oxides by adding the respective counterion. Whichever route is followed, the ion exchange functional groups of the matrix are regenerated; so IMS cycles can be repeated to increase the thickness of the MNPs or to produce bimetallic core-shell type MNPs. An extended version of the IMS is presented as using galvanic replacement for the preparation of Au- MNPs and AgAu-MNPs in cationic matrices using MNPs initially synthesized as nano-templates for crystallization of new mono or bimetallic MNPs. An important advantage provided by the IMS technique is its versatility, allowing the synthesis of BFNCs with the desired properties for different applications: bactericidal activity, magnetism, electrochemistry and heterogeneous catalysis, among others.

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Röder, Juliane [Verfasser], Ulrich [Akademischer Betreuer] Commandeur y Dirk [Akademischer Betreuer] Prüfer. "Displaying functional molecules on plant virus-based nanoparticles / Juliane Röder ; Ulrich Heinrich Commandeur, Dirk Prüfer". Aachen : Universitätsbibliothek der RWTH Aachen, 2018. http://d-nb.info/1181108861/34.

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