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Koh, Liling. "Investigations of bio-responsive peptide-inorganic nanomaterials." Thesis, Imperial College London, 2008. http://hdl.handle.net/10044/1/1376.
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Growth in nanotechnology has been fuelled by miniaturization of electronic systems, development of biomedical sciences and interest in nanomaterials that exhibit interesting properties. Current techniques to fabricate small devices have difficulty in accessing the size range between 10-100 nm, and conjugation of biomolecules with inorganic nanoparticles (NPs) can potentially be used to bridge this gap. Biological functions of living cells operate in the nanoscale and there is great potential in using bionanotechnology to discover new biomedical applications in diagnostics, drug delivery and cancer therapy. In this thesis, N-fluorenylmethoxycarbonyl (Fmoc)-protected peptides are explored as tethers to self-assemble gold NPs. Assembly is characterized by transmission electron microscopy, UV-visible spectroscopy, Raman spectroscopy, zeta potential measurements, dynamic light scattering and a new technique, Nanoparticle Tracking Analysis system (NTA). Solutions of gold NPs exhibit unique colour changes depending on their aggregation state, and the use of peptide-functionalised NPs (peptide-NPs) in a novel approach of protease sensing is developed here. Detection of the protease, Thermolysin from Bacillus thermoproteolyticus Rokko was demonstrated, and design of peptide-NPs was further optimized for detection of two medically relevant proteases, non-bindingto- alpha-chymotrypsin prostate specific antigen (nACT-PSA) and human neutrophil elastase (HNE). nACT-PSA and HNE are proteases related to prostate cancer and lung diseases respectively, and detection of PSA using the engineered peptide-NPs resulted in higher sensitivity than previously reported approaches. Surface enhanced Raman scattering was also used to monitor thermolysin action on peptide-NPs, in a novel approach which gave higher sensitivity than when using UVvisible spectroscopy for detection. The quartz crystal microbalance was also applied in complementary measurements to elucidate enzyme action on the peptides. The successful approach demonstrated here of using peptides to self-assemble gold NPs could pave new ways for the fabrication of small devices. Novel approaches of protease-sensing using peptide-NPs further illustrate potential of nanomaterials for new biomedical applications.
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Duan, Huanan. "Synthesis, integration, and characterization of functional inorganic nanomaterials." Worcester, Mass. : Worcester Polytechnic Institute, 2009. http://www.wpi.edu/Pubs/ETD/Available/etd-052809-122349/.
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Dissertation (Ph.D.)--Worcester Polytechnic Institute.Keywords: electrodeposition; chemical vapor deposition; AAO template-assisted nanofabrication; 1 D nanomateirals; inorganic nanomaterials; nanostructured electrode. Includes bibliographical references (leaves 102-103).
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Chen, Rong. "Synthesis, characterization and biological applications of inorganic nanomaterials." Click to view the E-thesis via HKUTO, 2006. http://sunzi.lib.hku.hk/hkuto/record/B36840907.
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Chen, Rong, and 陳嶸. "Synthesis, characterization and biological applications of inorganic nanomaterials." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2006. http://hub.hku.hk/bib/B36840907.
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Patil, Avinash J. "Novel organoclay based self-assembled bio-inorganic nanomaterials." Thesis, University of Bristol, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.409001.
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Alharthi, Fahad Ahmed A. "New inorganic nanomaterials for low-voltage transistor applications." Thesis, University of Hull, 2016. http://hydra.hull.ac.uk/resources/hull:16517.
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This research aims to synthesise and characterise solution-processable high-k dielectric nanorods, which are potentially suitable for use as the dielectric layer in low-voltage Organic Field-Effect Transistor (OFET) applications. Oleic acid-stabilised titanium dioxide nanorods (TiO2-OA), metal-doped anatase titanium oxide (TiO2-OA-M; M=Nb, In, or Nb/In) nanorods, rutile titanium oxide nanorods (TiO2) and barium titanium oxide nanorods (BaTiO3) have been prepared and investigated. Solution processable oleic acid-stabilised titanium dioxide nanorods (TiO2-OA) have been prepared by hydrolysis of titanium (IV) tetraisopropoxide (TTIP) with oleic acid (OA) as surfactant in the presence of trimethylamine N-oxide (TMAO). Furthermore, a series of ligand exchange reactions were carried out to replace the oleic acid bonded on the surface of TiO2-OA with diethyl 2-phenylethyl phosphonate (DEPPNA), octadecylphosphonic acid (ODPA) or octylphosphonic acid (OPA). The ligand exchange rate was characterised by a combination of 31P liquid NMR, ICP, CHN, and FT-IR. The solubility of the ligand-exchanged products in chlorobenzene was also investigated. A novel method based on the co-hydrolysis of titanium (IV) tetraisopropoxide (TTIP) and niobium or/and indium isopropoxide or ethoxide has been investigated to prepare solution-processable, oleic acid- stabilised, niobium- and indium-doped, anatase TiO2 nanorods (TiO2-OA-M; M = Nb, In or Nb/In). The effect of niobium and indium precursors, the molar ratio of Nb or In precursors/TTIP and reaction time on the composition, structure and morphology of the Nb or In doped TiO2 products have been investigated by a combination of XPS, XRD, ICP, CHN, FT-IR and TEM. Furthermore, a series of ligand exchange reactions were carried out to replace the oleic acid, which is bonded on the surface of TiO2-OA-M, with diethyl 2-phenylethyl phosphonate (DEPPNA) or octadecylphosphonic acid (ODPA). The solubility of the products in chlorobenzene was also investigated. Rutile titanium dioxide nanorods with different sizes were prepared by three different approaches. In the first approach,hair-like rutile nanorods TiO2 were prepared by simple hydrolysis of a TiOCl2 solution at low temperature (50, 70 and 90 °C). In the second approach, rutile nanorods TiO2 with a length of 150-200 nm and a width of 25-40 nm were prepared by using a hydrothermal treatment of TiOCl2 at 220 °C. In the third approach, rutile nanorods TiO2 with length of 80 nm and diameter of 20 nm were prepared by using an hydrothermal reaction of TiOCl2 in the presence of 3-hydroxytyramine hydrogen chloride, [(HO)2C6H3CH2CH2NH2·HCl] at 150°C. In order to improve the solubility of the obtained rutile titanium dioxide nanorods in organic solvents, different surface-modification methods have been investigated to coat the surface of the rutile titanium dioxide nanorods with various organic ligands. In the first method, a modification of the TiO2 nanorods with oleic acid (OA) in chlorobenzene was investigated. In the second method, a two-stage treatment of TiO2 nanorods in an acidic medium was studied, using a selection of oleic acid (OA), diethyl 2-phenylethyl phosphonate (DEPPNA), octylphosphonic acid (OPA) and decylphosphonic acid (ODPA) as ligands. In the third method, wet TiO2 nanorods before dry was directly modified with a range of oleic acid and amines, e.g., octylamine, dodecylamine and hexadecylamine, as ligands. All the products were characterized by a combination of XRD, ICP, CHN, FT-IR and TEM. The preparation of barium titanium oxide nanorods (BaTiO3) has been investigated by different approaches. In the first approach, a hydrothermal reaction was carried out to convert the titanium dioxide nanorods prepared in the first and third parts in this research into BaTiO3 nanorods. The effect of the molar ratio of Ba/Ti, the reaction pH, reaction time and temperature on the composition, structure and morphology of the products were fully investigated. In the second approach, a hydrothermal reaction using a single source Ba/Ti precursor, i.e., barium titanium ethylhexano-isoproxide BaTi(O2CC7H15)(OC3H7)5, was carried out to prepare barium titanium oxide nanorods. In the third approach, barium titanium oxide nanorods were prepared by using a hydrothermal reaction between barium chloride (BaCl2) and titanium oxy chloride (TiOCl2) in the presence of ethylene glycol as surfactant. All the products have been characterised by a combination of XRD, ICP, CHN, FT-IR and TEM.
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Nelo, M. (Mikko). "Inks based on inorganic nanomaterials for printed electronics applications." Doctoral thesis, Oulun yliopisto, 2015. http://urn.fi/urn:isbn:9789526210117.
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Abstract In this thesis several novel inks based on dry inorganic powders enabling magnetic, piezoelectric and memory resistive (memristive) function were researched for printed electronics applications. Low curing temperature screen–printable magnetic inks for high frequency applications based on dry cobalt nanoparticles were developed in the first part of the work. Three publications were achieved. The first one concentrated on ink formulation and its process development, the second on the utilization of multifunctional surfactant, and the third on the development of the inks for plastic substrates. The magnetic inks developed were cured at 120 °C. The electrical performance, microstructure, surface quality and mechanical durability of printed and cured layers were investigated. Relative permeability values up to 3 and related loss tangents up to 0.01 were achieved at 2 GHz frequency, as well as a pull–off strength of up to 5.2 MPa. The maximum loading level of cobalt nanoparticles was 60 vol–%, after which the stability of the ink started to degrade. The developed ink enabled the miniaturization of a patch antenna. In the second part of the thesis, the formulation of inks based on piezoelectric ceramic particles in powder form with ferroelectric polymers as a matrix material is introduced. The performance and quality of the printed inks and cured layers were investigated. The measured pull off –strength was up to 3.25 MPa, relative permittivity was up to 48 at 1 kHz and piezoelectric constant d31 up to 17 pm/V. The printed piezoelectric layer can be utilized in a pressure sensor. In the third part of the thesis, the development of inks for a novel printed memory component, a memristor, is researched. A synthesis route was developed for an organometallic precursor solution, which was formulated into inkjet–printable form. The printing tests were carried out in order to find the most feasible layer thickness with memristive behaviour. The influence of substrate materials and different thermal treatments on the components’ electrical properties, durability of read/erase –cycles and overall lifetime were also investigated. The prepared memristive patterns remained functional for up to 35 days, while the precursor solution remained usable for over a year. The memristive areas withstood up to 30 read/erase cycles and by utilizing heat treatments the shift in resistance value increased by up to three orders of magnitudeTiivistelmä Väitöstyössä kehitettiin epäorgaanisten kuivien jauhemaisten materiaalien pohjalta magneettisia, pietsosähköisiä ja memristiivisiä musteita käytettäviksi painettavan elektroniikan sovelluksissa. Työn ensimmäisessä osassa tutkittiin korkean taajuuden sovelluksissa käytettävien magneettisten, matalassa lämpötilassa kovetettavien, jauhemaisiin kobolttinanopartikkeleihin perustuvien silkkipainomusteiden valmistamista. Tulokset on esitetty kolmessa julkaisussa, joista ensimmäinen keskittyi musteen formulointiin, toinen monifunktionaalisen surfaktantin hyödyntämiseen ja kolmas musteen kehittämiseen muovialustalle sopivaksi. Työssä kehitettiin 120 °C:ssa kovettuvia musteita, joista valmistettujen kalvojen suhteellisen permeabiliteetin maksimiarvoksi saatiin 3 ja häviöiden minimiarvoksi 0,01 kahden gigahertsin taajuudella. Pull–off –vetotestin tulokseksi saatiin jopa 5,2 MPa. Musteet säilyivät vakaina enimmillään 60 tilavuusprosentin metallipitoisuudella. Kehitettyä mustetta käytettiin tasoantennin miniatyrisoinnissa. Toisessa osassa kehitettiin pietsosähköisiä musteita, jotka pohjautuivat keraamijauheeseen ja matriisimateriaalina toimivaan ferrosähköiseen muoviin. Niistä valmistettujen kalvojen parhaaksi pull off –vetotestin tulokseksi saatiin 3,25 MPa, permittiivisyyden maksimiarvoksi 48 yhden kilohertsin taajuudella ja d31–pietsovakion maksimiarvoksi jopa 17 pm/V. Kehitettyjä painettuja rakenteita voidaan käyttää painettavissa paineantureissa. Kolmannessa osassa kehitettiin uudentyyppinen painettava muistikomponentti, memristori ja komponenttien valmistamiseksi uusi prekursoriliuoksen synteesi. Syntetisoitu liuos muokattiin mustesuihkutulostettavaksi. Painokokeiden avulla selvitettiin materiaalin paksuus, jolla saatiin aikaan muistivastukselle ominainen memristiivinen käyttäytyminen. Työssä tutkittiin substraattimateriaalien ja mahdollisten lämpökäsittelyjen vaikutusta komponenttien sähköisiin ominaisuuksiin, luku/kirjoitussyklien kestoon sekä käyttöikään. Valmistetut memristiiviset kalvot säilyivät toimivina 35 vuorokautta ja prekursoriliuos yli vuoden. Memristiiviset pinnat kestivät jopa 30 luku/kirjoitussykliä ja vastusarvon muutos saatiin lämpökäsittelyllä kolmea kertaluokkaa suuremmaksi
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Eguchi, Daichi. "High Functionalization of Nanomaterials by Controlling Organic-Inorganic Interface." Kyoto University, 2017. http://hdl.handle.net/2433/227580.
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Schoth, Alexander [Verfasser]. "Structure control in polymer/inorganic hybrid nanomaterials / Alexander Schoth." Mainz : Universitätsbibliothek Mainz, 2017. http://d-nb.info/1126058068/34.
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Starkey, Christopher L. "Continuous-flow hydrothermal and solvothermal synthesis of inorganic nanomaterials." Thesis, University of Nottingham, 2016. http://eprints.nottingham.ac.uk/37016/.
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Nanomaterials and nanotechnology are presently receiving high levels of interest which is aiding significant advancements to industrial and technological applications. New strategies towards nanoparticle synthesis are needed to produce high quality nanomaterials at industrially viable levels. This thesis presents the continuous flow hydrothermal and solvothermal synthesis (CFHSS) of a range of inorganic nanomaterials produced using a continuous-flow reactor designed at the University of Nottingham. The materials presented herein are currently industrially applicable or projected future trend materials. The aim is to widen the library of materials accessible via this relatively new synthetic strategy. It is mostly concerned with the development of the synthetic protocol towards specific materials and classes of materials, via both chemical and reactor configuration innovations, but additionally yields information about the chemical processes occurring within the reactor and how these can be controlled and exploited. This provides insight into not only the reactor but the field of CFHSS as a whole. Selected materials are subject to application based testing. With a fully industrial scale facility under construction, promising materials are trialled at pilot scale to assess the viability of the transfer of chemistry from laboratory to pilot scale with industrial scale production in mind. Chapter 1 provides an introduction to nanotechnology and nanomaterials in general, giving background to their unique properties and application. Traditional routes of synthesis are discussed, with particular focus then given to hydrothermal methods and continuous flow reactor design and nanoparticle production. Chapter 2 presents the characterisation techniques used in this thesis in terms of their theory and application. Application specific testing of the materials is explained in the relevant chapters. Chapter 3 reports the production of two different metal oxide materials, namely titania and doped titania photocatalyts, and barium strontium titanate nanopowders. Photocatalysis results are reported for the titania nanocrystals, and the barium strontium titanate nanopowders are produced in the first fully hydrothermal continuous flow synthesis at both laboratory and pilot scales to assess their viability for industrial scale production. Chapter 4 presents the development of the first continuous flow hydrothermal production of metal sulphide nanomaterials, via a general route using thiourea as the sulphur source. Full synthetic details and characterisation are discussed, together with information yielded about the materials and reactor and the implications this may have on future materials synthesis using CFHS and the Nottingham reactor. Chapter 5 details firstly batch hydrothermal and solvothermal synthesis of lithium iron phosphate materials to investigate the effect of a range of conditions on the reaction pathway and resulting products, followed by a translation of the knowledge learned into continuous flow hydrothermal and solvothermal reactions using the counter-current reactor. Scale up of the synthesis is achieved, together with electrochemical testing of selected products. Finally, chapter 6 provides general conclusions, summaries and outlooks for future work.
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Di, Pietro Patrizia. "Hybrid organic-inorganic nanomaterials for applications at the biointerfaces." Doctoral thesis, Università di Catania, 2017. http://hdl.handle.net/10761/3843.
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In the last few years, the application of nanomaterials (NMs) as theranostic devices, which combine diagnostic and therapeutic features, has gained a tremendous interest and development. Still, the major challenge is the understanding of the many and often complex processes that occur during the interaction of biological compounds with nanomaterials, in order to modulate their responses to the fixed target. A fine development of such smart nanosystems could occur only by a critical control of chemical/physical properties of NMs at the biological interfaces.
According to such premises, this thesis deals with the investigation of NMs at the biointerfaces for potential theranostic applications. Specifically, the work has been addressed to the synthesis and characterization of several inorganic and organic nanomaterials, including gold and silver nanoparticles, hydroxyapatite, graphene and graphene oxide nanosheets tailored at the surface with stimuli-responsive polymers (polyacrylate and/or polyacrylamide) or specific chemical functionalities (amine functionalisation, sulphur functionalisation). As to the biomolecular counterpart, the performed study involved proteins (ferritin and albumin), drugs (curcumin), peptides mimicking proteins of relevant biomedical interest (such as RGD - the cell adhesive sequence of several extracellular matrix proteins-, neurotrophin peptides, fragments of the vascular endothelial growth factor), artificial membranes (lipid liposomes and supported lipid bilayers), and cells (neuroblastoma, endothelial cells, retinal pigment epithelial cells).
The hybrid nano-bio-interface between the chosen NMs and biomolecules was scrutinized by a multi-technique approach, which relies on various physico-chemical spectroscopic (UV-visible, FT-IR, RAMAN, X-ray photoelectron spectroscopy), microscopic (atomic force microscopy, scanning electron microscopy, transmission electron microscopy, laser scanning confocal microscopy) and spectrometric (Time-of-Flight secondary ion mass spectrometry) methods. The research methodology used was interdisciplinary as well as the performed research, also including some biological assays on cell viability, nanoparticle internalisation by cellular uptake and nanotoxicity.
The obtained results suggest promising applications for further development of these smart nanosystems for theranostic purposes.
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Liu, Dongfang. "Chemical hybridization of fullerenes, [pi]-electron systems and inorganic nanomaterials /." View abstract or full-text, 2008. http://library.ust.hk/cgi/db/thesis.pl?CHEM%202008%20LIU.
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Thachepan, Surachai. "Synthesis and characterization of bio-inorganic nanomaterials in self-organized media." Thesis, University of Bristol, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.445830.
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Viravaidya, Chulanapa. "Controlled synthesis of bio-relevant inorganic nanomaterials using constrained reaction environments." Thesis, University of Bristol, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.432959.
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Rieter, William J. Lin Wenbin. "Development of inorganic-organic hybrid nanomaterials for biological and biomedical applications." Chapel Hill, N.C. : University of North Carolina at Chapel Hill, 2008. http://dc.lib.unc.edu/u?/etd,1979.
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Thesis (Ph. D.)--University of North Carolina at Chapel Hill, 2008.Title from electronic title page (viewed Dec. 11, 2008). "... in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Department of Chemistry." Discipline: Chemistry; Department/School: Chemistry.
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Berestok, Taisiia. "Assembly of colloidal nanocrystals into porous nanomaterials." Doctoral thesis, Universitat de Barcelona, 2018. http://hdl.handle.net/10803/663275.
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This thesis focuses on different aspects of NCs colloidal synthesis, the exploration of the relevant surface chemistries that afford NC assembly and the NC implementation into porous nanomaterials.
The work is divided into two blocks. The first block is devoted to developing and optimizing the synthesis of NCs followed by the examination of their suitability for potential applications in catalysis and photocatalysis. The second block is dedicated to establish procedures to fabricate single-component or multicomponent porous nanomaterials from NC building blocks. To embrace the use of the developed strategies in different application fields, several kind of materials were under research. Namely, metals (e.g. Au), metal oxides (e.g. CeO2, TiO2, Fe2O3), metal chalcogenides (e.g. In2S3, ZnS, PbS, CuGaS2 and Cu2ZnSnSe4), and their composites.
CeO2 NCs synthesis was deeply investigated with the aim to achieve a proper control on the NCs morphology, facets exposed, crystal phase, composition, etc., required for application. Overall, CeO2 NCs with spherical, octapod-like branched, cubic hyperbranched, and kite-like morphology with sizes in the range 7 to 45 nm were produced by adjusting experimental conditions of the synthetic protocol. Branched and hyperbranched NCs showed higher surface areas, porosities and oxygen capacity storage values compared to quasi-spherical NCs.
The NCs morphology-controlled synthesis has been extended to quaternary Cu2ZnSnSe4 (CZTSe). CZTSe NCs with narrow size distribution and controlled composition were produced. It was shown how off-stoichiometric CZTSe compositions were characterized by higher charge carrier concentrations and thus electrical conductivities.
The strategy to functionalize the metal oxide NC surface composition by applying different ligands is proposed. This enables to develop a novel approach to assemble metal oxide NCs into porous gel and aerogel structures. Propylene oxide has been found to trigger the gelation process of glutamine functionalized NCs. The detailed investigation of the gelation mechanism is demonstrated for the case of ceria. The method is applied for NCs with different morphologies. Eventually, the versatility of the concept is proved by using of the proposed approach for the TiO2 and Fe2O3 nanocrystals.
The assembly method has been extended to metal chalcogenides - In2S3 NCs - starting from the NCs synthesis, with further surface chemistry manipulation and eventually follows by the NC assembly into gels and aerogels. The optimization of NC surface chemistry was achieved by testing different ligand exchange approaches via applying short-chain organic and inorganic ligands. The assembly method based on ligand desorption from the NC surface and chalcogenide-chalcogenide bond formation has been established for In2S3. The comparison of the different ligands impact on the NC performance in colloidal form, when assembled into gels and when supported onto substrate is investigated towards photoelectrocatalysis.
The oxidative ligand desorption assembly approach has been extended for multicomponent NCs for the case of CuGaS2 and CuGaS2-ZnS. Optimization of spin-coating process of the formed NCs inks followed by applying of sol-gel chemistry led to formation of highly porous layers from TGA-CuGaS2 and TGA-ZnS. Applied results of CuGaS2/ZnS nanocrystal-based bilayers and CuGaS2–ZnS nanocrystal-based composite layers have been shown by testing their photoelectrochemical energy conversion capabilities.
The approach to adjust NC surface chemistry has been proposed and tested for performing multicomponent NC assemblies. Applying of different ligands for NC surface functionalization endows their surface with different charges which usually provides colloidal NCs stabilization. It has been found that mixing of oppositely
charged NCs with certain concentration enabled their assembly/gelation via electrostatic interaction. The proposed approach has been applied and optimized to produce multicomponent NC gels and aerogels. The detailed investigation of the gelation mechanism is shown for combination of metal-metal oxide and metal oxide-metal chalcogenide NCs (Au-CeO2, CeO2-PbS). Applied results of the Au-CeO2 aerogels were demonstrated for CO-oxidation.Esta tesis se centra en la síntesis coloidal de nanocristales (NCs), en la exploración de su química de superficie y en su ensabanado en nanomateriales porosos funcionales. Para demostrar la versatilidad de aplicación de dichas estructuras, en este estudio se han considerado NCs de distintos tipos de materiales: metales (Au), óxidos metálicos (CeO2, TiO2, Fe2O3), calcogenuros metálicos (In2S3, ZnS, PbS, CuGaS2,Cu2ZnSnSe4) y sus materiales compuestos. El trabajo se dividió en dos bloques. En el primero se desarrolló y optimizó la síntesis de NCs de óxidos y calcogenuros metálicos y se evaluó su potencial para aplicaciones de catálisis y fotocatálisis. Se investigó en profundidad la síntesis de NCs de CeO2, poniendo énfasis en controlar su morfología. Se consiguió producir NCs de CeO2 de forma controlada (esférica, octapodo ramificado, cúbico ramificado y romboidal) y con tamaño controlado (7-45 nm). Asimismo, se obtuvieron NCs de Cu2ZnSnSe4 con una fina distribución de tamaños y composición controlada. En el segundo bloque se establecieron y estudiaron procedimientos para fabricar nanomateriales porosos mono- o multicomponentes a partir del ensamblado de NCs. Se desarrolló una estrategia basada en el ajuste de la química de superficie de NCs de óxidos metálicos (CeO2, Fe2O3,TiO2) y de calcogenuros metálicos (In2S3, CuGaS2-ZnS) que permitió su ensamblaje controlado en estructuras porosas de tipo gel y aerogel. En el caso de los óxidos metálicos, se determinó que el ensamblado se inicia con la adición de un epóxido a NCs funcionalizados con glutamina, causando la gelación. La desorción oxidativa de ligandos basada en la formación de enlaces calcogenuro-calcogenuro se propuso como mecanismo de gelación en calcogenuros mono- (In2S3) y multicomponente (CuGaS2-ZnS). Se investigó el impacto del empleo de distintos ligandos en la eficiencia foto-electrocatalítica de NCs en forma coloidal, ensamblados en geles y soportados en sustratos. Se desarrolló y estudió el ajuste de la química de superficie de NCs para la obtención de ensamblajes multicomponente mediante interacción electrostática de coloides en suspensión. El mecanismo de gelación fue investigado al detalle para materiales compuestos de NCs de oxido metálico (CeO2) con NCs de óxido de calcogenuro (PbS-CeO2) y metálicos (Au-CeO2). Los aerogeles de Au-CeO2 demostraron potencial para la oxidación de CO.
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Navarrete, Gatell Eric. "Synthesis and gas sensing properties of inorganic semiconducting, p-n heterojunction nanomaterials." Doctoral thesis, Universitat Rovira i Virgili, 2021. http://hdl.handle.net/10803/672438.
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En aquesta tesis utilitzant principalment Aerosol Assited Chemical Vapor Deposition, AACVD, com a metodologia de síntesis d'òxid de tungstè nanoestructurat s'han fabricat diferents sensors de gasos. Per tal d'estudiar la millora en la selectivitat i la sensibilitat dels sensors de gasos basats en òxid de tungstè aquest s'han decorat, via AACVD, amb nanopartícules d'altres òxids metàl·lics per a crear heterojuncions per tal d'obtenir un increment en la sensibilitat electrònica, les propietats químiques del material o bé ambdues. En particular, s'han treballat en diferents sensors de nanofils d'òxid de tungstè decorats amb nanopartícules d'òxid de níquel, òxid de cobalt i òxid d'iridi resultant en sensors amb un gran increment de resposta i selectivitat cap al sulfur d'hidrogen, per a l'amoníac i per a l'òxid de nitrogen respectivament a concentracions traça. A més a més, s'han estudiat els mecanismes de reacció que tenen lloc entre les espècies d'oxigen adsorbides a la superfície del sensor quan interactua amb un gas. I també s'ha treballat en intentar controlar el potencial de superfície de les capes nanoestructurades per tal de controlar la deriva en la senyal al llarg del temps, quan el sensor està operant, a través d'un control de temperatura.En esta tesis utilizando principalmente Aerosol Assited Chemical Vapor Deposition, AACVD, como metodología de síntesis de óxido de tungsteno nanoestructurado se han fabricado diferentes sensores de gases. Para estudiar la mejora en la selectividad y la sensibilidad de los sensores de gases basados en óxido de tungsteno estos se han decorado, vía AACVD, con nanopartículas de otros óxidos metálicos para crear heterouniones para obtener un incremento en la sensibilidad electrónica, las propiedades químicas del material o bien ambas. En particular, se han trabajado en diferentes sensores de nanohilos de óxido de tungsteno decorados con nanopartículas de óxido de níquel, óxido de cobalto y óxido de iridio resultante en sensores con un gran incremento de respuesta y selectividad hacia el sulfuro de hidrógeno, para el amoníaco y para el óxido de nitrógeno respectivamente a concentraciones traza. Además, se han estudiado los mecanismos de reacción que tienen lugar entre las especies de oxígeno adsorbidas en la superficie del sensor cuando interactúa con un gas. Y también se ha trabajado en intentar controlar el potencial de superficie de las capas nanoestructuradas para controlar la deriva en la señal a lo largo del tiempo, cuando el sensor está trabajando, a través de un control de temperatura.
In this thesis, using mainly Aerosol Assited Chemical Vapor Deposition, AACVD, as a synthesis methodology for nanostructured tungsten oxide, different gas sensors have been manufactured. To study the improvement in the selectivity and sensitivity of gas sensors based on tungsten oxide, they have been decorated, via AACVD, with nanoparticles of other metal oxides to create heterojunctions to obtain an increase in electronic sensitivity, in the chemical properties of the material or at the same time in both. Particularly, we have worked on different tungsten oxide nanowire sensors decorated with nanoparticles of nickel oxide, cobalt oxide and iridium oxide resulting in sensors with a large increase in response and selectivity towards hydrogen sulfide, for ammonia. and for nitrogen oxide respectively at trace concentrations. In addition, the reaction mechanisms that take place between oxygen species adsorbed on the sensor surface when it interacts with a gas have been also studied. Furthermore, efforts have been put on trying to control the surface potential of the nanostructured layers to control the drift in the signal over time, when operating the sensors, through temperature control.
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Howlader, Ashraful Hossain. "Morphology Engineering of Sn-Based All-Inorganic Perovskite Films for Photodetector Applications." Thesis, The University of Sydney, 2021. https://hdl.handle.net/2123/27282.
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At present, halide perovskite (HP) materials, as a family of promising semiconductors, have been a hot topic in the field of energy and optoelectronic technologies. These materials offer a range of remarkable properties like large absorption coefficients, tunable bandgaps, high carrier mobilities, and long carrier diffusion lengths, etc. Besides these physical properties, due to their low-cost and low-temperature solution processability, HPs are becoming materials of research interests among researchers. Among various optoelectronic applications based on perovskites, photodetectors are the remarkable one which has attached considerable research interests. However, efficient photo-generated carrier extraction and faster carrier transport are the fundamental requirements for good photodetection. Unfortunately, during perovskite thin film (PTF) preparation through the solution process, pinhole generation is prevalent. Therefore, photo-generated carrier face unwanted recombination and trapping. These pinholes are the product of atomic vacancies (AV), and AVs are one of the main causes of hysteresis. In this respect, morphology engineering (ME) of solution-processed PTFs to mitigate hysteresis is mandatory. Exploring different anti-solvents treatments is an option. Carbon nanomaterials (CNM) also can help to reduce unwanted recombination and trappings by improving the TFs’ quality. Among various CNMs, the carbon nanotubes (CNT) are very suitable to make promising composite TFs for high-performance devices. CNTs also help in efficient carrier extraction and faster transmission. Again, all-inorganic perovskites (AIP) offer better stability compared to organic-inorganic hybrid perovskites (OIHP) in an ambient environment. Moreover, the popular Pb-based AIPs pose a potential environmental threat. In this thesis, I am interested in exploring the ME and hybridization of AIPs (CsSnI3) with CNTs and related photodetectors.
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Pomogailo, A. D. "Synthesis and Structure of Intercalated Organo-inorganic Nanocomposites." Thesis, Sumy State University, 2012. http://essuir.sumdu.edu.ua/handle/123456789/35070.
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The synthesis and structure of organo–inorganic nanocomposites prepared by intercalation of monomers
or polymers into the interlayer galleries of layered matrices are analyzed. General features and the mechanism
of the intercalation process, as well as materials used for this purpose, mostly often naturally occurring
materials (clays, silicates, layered phosphates, chalcogenides, and other moieties hosts), are discussed.
Mechanisms governing the intercalation of monomers or polymer repeating units into the interlayer
galleries as guests are compared. One of the most widespread and commercially important intracrystalline
chemical reactions is the incorporation of monomer molecules into pores or layered lattices of the host substances
with subsequent post-intercalation transformations into polymer, oligomer, or hybrid–sandwich
products. Particular emphasis is placed on nanocomposites based on epoxy polymers and various mineral
matrices. Basic application areas of hybrid nanomaterials are considered.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/35070
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Peterson, Alisha D. "Synthesis and Characterization of Novel Nanomaterials: Gold Nanoshells with Organic- Inorganic Hybrid Cores." Scholar Commons, 2010. http://scholarcommons.usf.edu/etd/3612.
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Gold nanoshells, a material generally composed of a core of silica surrounded by
a thin shell of gold, are of great interest due to their unique and tunable optical properties.
By varying the shell thickness and core size, the absorption and scattering properties are
greatly enhanced. The nanoshells can be made to absorb or scatter light at various
regions across the electromagnetic spectrum, from visible to the near infrared. The
ability to tune the optical properties of nanoshells allows for their potential use in many
different areas of research such as optical imaging, tumor ablation, drug delivery, and
solar energy conversion. The research in this thesis focused on the synthesis and
characterization of two novel gold nanoshell materials containing thermally-responsive,
organic-inorganic hybrid layers. One type of material was based on a two-layer particle
with a thermally responsive hybrid core of N-isopropylacrylamide (NIPAM)
copolymerized with 3-(trimethoxysilyl)propyl methacrylate (MPS) that was then coated
with a thin layer of gold. The second material was a three-layer particle with a silica
core, a thermally responsive copolymer of NIPAM and MPS middle layer and an outer
shell of gold. Various techniques were used to characterize both materials. Transmission
electron microscopy (TEM) was used to image the particles and dynamic light scattering
(DLS) was used to determine particle size and the temperature response. Additionally,
UV-Vis spectroscopy was used to characterize the optical properties as a function of
temperature.
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Tsui, Hei Man. "Synthesis and Characterization of Magnetic Cabides and Oxides Nanomaterials." VCU Scholars Compass, 2018. https://scholarscompass.vcu.edu/etd/5366.
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The design and development of nanoparticles is of great interest in the current energy and electronic industry. However, based on the current materials available the production cost can be high with insignificant magnetic and mechanical properties. Specifically, rare-earth magnetic materials composed of neodymium and samarium are known for their high magnetic performance, however, due to the cost of development there is a need to develop a versatile and cost effective material. Alternatively, cobalt carbide nanomaterials have shown to be a promising alternative for rare-earth free magnets as they exhibit comparable properties as hexaferrite magnetic materials. The primary goal of this dissertation focuses on the development of nanoparticles for permeant magnetic, and magnetic refrigeration applications. The first part of this work focuses on the synthesis of cobalt carbide (CoxC, x=2,3) nanoparticles using a novel polyol synthesis method by introducing a small amount of Ru, Cu, or Au as nucleating agent. It was found that the morphology and magnetic properties of the as-synthesized CoxC nanoparticles change as a result of directional growth of nanoparticles using nucleating agents. Needle-like particle morphology ranges from 20-50 nm in width and as long as 1 µm in length were synthesized using Ru as nucleating agent. These particles exhibit magnetization saturation of 33.5 emu/g with a coercivity of 2870 Oe and a maximum energy product 1.92 MGOe (BHmax) observed. Particle morphology is a critical aspect in the development of magnetic nanoparticles as anisotropic particles have shown increased coercivity and magnetic properties. These CoxC nanomaterials have a higher maximum energy product compared to previous work providing further insight into the development of non-rare earth magnetic material.
The second part of this dissertation work focuses on the sol-gel synthesis of perovskite LaCaMnO3 (LCMO) nanomaterials. In this process, various chain lengths of polyethylene glycol (PEG) was added into a solution consisting of La, Ca, and Mn salts. The solution was left for the gelation process, and high temperature sintering to obtain the final product. By varying the polymer chain of the PEG, the size of the as synthesized LaCaMnO3 nanomaterials were altered. The as-synthesized LCMO nanomaterials have shown a maximum change in magnetic entropy (-ΔSM) was found to be 19.3 Jkg-1K-1 at 278 K for a field change of 0-3 T and 8.7 Jkg-1K-1 for a field change of 0-1 T. This is a significant improvement in comparison to current literature of the material suggesting that this is a promising alternative to Gd materials that is prone to oxidation. With additional development, LCMO or related maganites could lead to application in commercial technologies.
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Huba, Zachary. "Synthesis and characterization of cobalt carbide based nanomaterials." VCU Scholars Compass, 2014. http://scholarscompass.vcu.edu/etd/3320.
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Permanent magnets are used heavily for multiple applications in industry and current electronic technologies. However, the current permanent landscape is muddled by high cost of materials and insufficient magnetic or thermal properties. The primary focus of this dissertation work is the synthesis and optimization of a new permanent magnetic material, in the form of cobalt carbide nanomaterials. The optimization revolved around controlling the crystal phase and particle shape of synthesized cobalt carbide particles; these parameters have significant impact on the observed magnetic properties of magnetic nanoparticles. Co3C was identified to be the preferred crystal phase, leading to better magnetic properties. Cobalt Fumarate was found to be the ideal precursor to synthesize anisotropic Co3C particles and enhance magnetic properties of the synthesized cobalt carbide particles. Lastly, an ethanol based reduction system was employed to develop the greener synthesis of Co and Ni magnetic particles.
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Buckley, Hannah C. "Applications of layered double hydroxides as inorganic adjuvants." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:353bd7f3-89ed-4392-9b71-64a27c271522.
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The primary aim of this thesis is to explore the immunostimulatory properties of a family of layered, crystalline, inorganic materials known as layered double hydroxides (LDHs). Chapter One provides an introduction to relevant aspects of the immune system, and the context for investigating the immunostimulatory properties of inorganic materials in terms of vaccine/adjuvant formulations. The possible mechanisms of action of commercial adjuvant materials are also reviewed, and the structure, synthesis methods and applications of LDHs are discussed. Chapter Two details the controlled synthesis and characterisation of LDHs in specific particle sizes. A series of MgAl-CO3 LDHs with precisely controlled particle sizes ranging from 20 to 10000 nm were successfully synthesised, then the techniques used were extended to other compositions to create a panel of LDHs for use in subsequent Chapters. In Chapter Three, the responses of monocyte-derived dendritic cells (Mo-DC) to the LDH particle sizes discussed in Chapter Two are assessed in terms of viability, surface molecule expression, and cytokine secretion. A statistical modelling approach using the physicochemical properties of the LDHs as explanatory variables for immune responses was employed to evaluate the validity of the model formulated in the previous work, and to establish if particle size could be used to improve its predictive ability. It was found that strong relationships between LDH particle size and certain Mo-DC responses exist, and that these responses could be predicted with a high degree of accuracy. Chapter Four is concerned with the investigation of T cell responses to LDH-stimulated allogeneic Mo-DC. Various methods were used for assessing T cell division and proliferation, and a protocol for intracellular cytokine staining was developed to probe T cell polarisation. Five LDHs, which have elicited potentially interesting T cell responses in previous work, were selected for investigation. However, using the assays described, no discernible improvement in proliferation or polarisation was observed with any of the LDHs tested. Chapter Five presents an initial exploration of the interactions between LDH particles and cells. Experiments have shown that LDH particles both adhere to and are internalised by Mo-DC. Variations in the extent of internalisation with both particle size and composition were highlighted by confocal microscopy studies. Through investigations into interactions between LDH particles and the plasma membrane using protease enzymes, it was revealed that adhesion of LDH particles is partly protein-dependent. Further studies have also demonstrated a pH-dependent element to particle association with Mo-DC. Details of the experimental procedures employed are included in Chapter Six. Supplementary information referred to in the main thesis may be found in the Appendices.
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Lisowski, Carmen Ellen 1978. "Hybrid organic/inorganic nanomaterials: Development of malonamide-functionalized nanoparticles designed for lanthanide ion detection." Thesis, University of Oregon, 2010. http://hdl.handle.net/1794/10523.
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xviii, 174 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.Hybrid nanoscale complexes incorporate the attributes of organic and inorganic components to yield novel multifunctional materials. Because the individual components themselves and the combinations used can be widely varied to tune the properties of the resulting complex, the potential for new properties and practical applications is nearly limitless. However, widespread use of these materials relies on appropriate design, synthesis and characterization strategies to ensure proper function and compositional integrity. This dissertation describes the chemistry of these hybrids, made possible by combining organic ligands, inorganic nanoparticles, and metal ions, and the interesting optical and spectroscopic properties associated with the hybrid nanomaterials. Organic ligands containing Bunte salt and acyclic malonamide functionalities were attached to gold nanoparticles to produce colorimetric sensors for lanthanide ion detection. Bunte salt functionality stabilizes the gold core and malonamide functionality offers selective and sensitive lanthanide ion binding. The binding interaction controls a nanoparticle cross-linking event that changes the color of the nanoparticle solution, resulting in visual, colorimetric lanthanide ion detection. Next, the concentration of malonamide ligand was diluted and replaced with a diluent ligand yielding nanoparticles stabilized with a mixed ligand composition. The mixed ligand environment makes the optical response of the colorimetric sensor reversible. Furthermore, the use of Bunte salt ligands during nanoparticle synthesis has allowed the investigation of the role of reducing agent on nanoparticle stability. In addition to exploring interactions pertaining to gold nanoparticle complexes, a new approach to sensitize europium ion luminescence was developed by fabricating a zinc oxide/europium complex. A molecular linker permits simultaneous zinc oxide nanoparticle functionalization and trivalent europium binding in order to tether the europium ion close to the nanoparticle surface. The zinc oxide nanoparticle can then act as an inorganic antenna, transferring energy to the europium ion and enhancing its luminescence. Finally, a strategy was developed to synthesize bifunctional bicyclic malonamides. Synthesis of these ligands allows the enhanced f-block ion binding affinity of bicyclic malonamides to be incorporated into functional materials to compare their performance to our previously prepared acyclic malonamide hybrid complexes. This dissertation includes my previously published and co-authored materials.
Committee in charge: Darren Johnson, Chairperson, Chemistry; James Hutchison, Advisor, Chemistry; Catherine Page, Member, Chemistry; Michael Haley, Member, Chemistry; Barbara Roy, Outside Member, Biology
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Raju, D. "Studies on metal accumulation and synthesis of inorganic nanomaterials in plants and their applications." Thesis(Ph.D.), CSIR-National Chemical Laboratory, Pune, 2012. http://dspace.ncl.res.in:8080/xmlui/handle/20.500.12252/2132.
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Skowron, Stephen T. "Irradiation induced reactions in carbon nanomaterials in transmission electron microscopy." Thesis, University of Nottingham, 2016. http://eprints.nottingham.ac.uk/34629/.
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Aberration corrected transmission electron microscopy is a powerful tool for the structural characterisation of materials at the atomic scale, but the passage of high velocity electrons through the material can often induce structural changes via the transfer of large amounts of energy from the beam. The work in this thesis theoretically considers the nature of this transfer of energy and its impact upon the material being studied. The computational modelling of molecular species encapsulated inside carbon nanotubes and their response to electron irradiation is compared to results from TEM experiments, and used to explain the experimental observations. The high rate of destruction of C-H bonds under the beam is quantified, and its implications for TEM studies of organic materials considered. An effective solution for mitigating this rate of destruction is found, applied to a model system, and then confirmed experimentally. Using the considerations of stability under the beam, two experimentally witnessed reactions are investigated in detail, and careful comparison to intermediate structures observed in TEM allows full reaction mechanisms to be proposed. The dynamic motion of atomic defects in irradiated graphene is considered with the aid of a large library of experimental TEM images. A novel defect structure is observed, and is seen to undergo structural rearrangements on a quicker time-scale than accessible to TEM imaging. This species enables the very quick migration of defect structures across the graphene lattice, and is attributed to a trivacancy structure. The rates of beam induced reactions are considered in the framework of chemical kinetics, and a method for extracting kinetic parameters of a reaction from the statistics of a large number of TEM observations of it occurring is developed. This is used to obtain the first cross-sections for the formation and healing of the irradiation induced Stone-Wales bond rotation, and the first experimental activation energy for its healing. The latter agrees well with a theoretically predicted mechanism of catalysis, while the former demonstrates that the widely assumed process of direct knock-on damage cannot be responsible for the beam induced reaction. An alternative mechanism is proposed, resulting from the electronic excitation of the defect.
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Han, Chenhui. "Nanomaterials stabilized pickering emulsions and their applications in catalysis." Thesis, Queensland University of Technology, 2019. https://eprints.qut.edu.au/134131/1/Chenhui%20Han%20Thesis_Redacted.pdf.
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This thesis is an exploratory study of nanomaterials stabilized Pickering emulsions and their applications. The study illustrates some novel emulsion behaviour through dynamic observation and develops a mechanically switchable emulsion based on the microstructure design of nanomaterials. The droplets of emulsion are demonstrated as an effective microreactor for chemical reactions that happen at the oil-water interface, showing the potential application of Pickering emulsion in catalysis.
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Prebe, Arnaud. "Different routes for synthesis of Poly(lactic acid) : silicon-based hybrid organic-inorganic nanomaterials and nanocomposites." Lyon, INSA, 2010. http://theses.insa-lyon.fr/publication/2010ISAL0015/these.pdf.
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The general aim of this work was to study the different routes that can be taken in order to generate a polymer-nanocomposite taking into account the current knowledge in this scientific domain. Consequenlty, four routes were studied: The first route starts from the preformed inorganic phase, i. E. Fumed silica, and the polymer matrix, i. E. Poly(lactic acid) (PLA). The second route starts from the preformed inorganic filler and PLA monomer, i. E. L-Lactide, in order to in-situ polymerize the L-Lactide in the presence of the fumed silica. The third route starts from the preformed polymer matrix, i. E. PLA, and the use of alkoxysilane as precursors for in-situ generation of an inorganic-rich phase into the polymer. The fourth and last route combines the generation of the inorganic-rich phase and the polymerization of the organic monomer. The objectives of this work focused on the chemical paths and processes instead of the final properties of the resulting nanocomposites. Due to the very broad series of PLA-based nanocomposites which could be generated from the different routes, we choose to have a special attention on the chemistry(ies) involved. Finally, the different routes leading to various types of PLA-nanocomposites in terms of molar mass, crystallinity and morphology were reported. The key point for having a high better state of dispersion seems to depend on the process as we demonstrated that the extrusion step offers high shear enabling a good dispersion. Moreover, it was shown that compatibility between the PLA matrix and the inorganic phase can be tailored by the functionality of the nanofiller surface or the functional groups of an interfacial agentL’acide polylactique génère depuis quelques années un engouement certain puisqu’il apparaît comme un des biopolymères les plus aptes à remplacer les polymères issus de l’industrie pétrolière. Toutefois, afin de pouvoir prétendre remplacer ces polymères dans les applications tel que l’emballage, etc. , les propriétés mécanique se doivent d’être au moins égale. Il est maintenant bien reconnu qu’il est possible d’accroitre une multitude de propriété en nanostructurant à l’aide d’une phase inorganique les polymères. Cependant il existe plusieurs possibilité quand au procédé choisi. Ici on se propose d’étudier la production d’un nanocomposite à base d’acide polylactique et d’une phase inorganique siliconée en utilisant différentes voies de production. En premier lieu, la synthèse in-situ du PLA en présence de silice pyrogénée a été étudiée tout en faisant varier la compatibilité par la fonctionnalisation en surface. Ensuite la génération de la phase inorganique à partir de précurseur alkoxysilane a été menée directement dans l’acide polylactique fondu par extrusion réactive avec l’ajout ou non d’agent d’interface. Puis les deux voies ont été combinées afin de générer la phase inorganique dans le monomère fondu (L-Lactide) puis de polymériser celui-ci dans le même réacteur. Enfin ces trois voies ont été comparées entre elles et avec le simple mélangeage dans le fondu de silice pyrogénée avec l’acide polylactique en extrusion
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Abouserie, Ahed [Verfasser], Andreas [Gutachter] Taubert, Stefanie [Gutachter] Dehnen, and Peer [Gutachter] Schmidt. "Ionic liquid precursors for multicomponent inorganic nanomaterials / Ahed Abouserie ; Gutachter: Andreas Taubert, Stefanie Dehnen, Peer Schmidt." Potsdam : Universität Potsdam, 2018. http://d-nb.info/1218404043/34.
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Lee, Michael M. "Organic-inorganic hybrid photovoltaics based on organometal halide perovskites." Thesis, University of Oxford, 2013. http://ora.ox.ac.uk/objects/uuid:9384fc54-30de-4f0d-86fc-71c22d350102.
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This thesis details the development of a novel photovoltaic device based on organometal halide perovskites. The initial focus of this thesis begins with the study of lighttrapping strategies in solid-state dye-sensitised solar cells (detailed in chapter 3). While I report enhancement in device performance through the application of near and far-field light-trapping techniques, I find that improvements remain step-wise due to fundamental limitations currently employed in dye-sensitised solar cell technology— notably, the available light-sensitising materials. I found a promising yet under researched family of materials in the methyl ammonium tri-halide plumbate perovskite (detailed in chapter 4). The perovskite light-sensitiser was applied to the traditional mesoscopic sensitised solar cell device architecture as a replacement to conventional dye yielding world-record breaking photo-conversion e!ciencies for solid-state sensitised solar cells as high as 8.5%. The system was further developed leading to the conception of a novel device architecture, termed the mesoporous superstructured solar cell (MSSC), this new architecture replaces the conventional mesoporous titanium dioxide semiconductor with a porous insulating oxide in aluminium oxide, resulting in very low fundamental losses evidenced through high photo-generated open-circuit voltages of over 1.1 V. This development has delivered striking photo-conversion ef- ficiencies of 10.9% (detailed in chapter 6).
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Di, Pasqua Anthony J. "Carboplatin Exploring mechanism of action and improved drug delivery 1. Role of carbonate in the mechanism of action of carboplatin 2. Cytotoxicity of mesoporous silica nanomaterials /." Related electronic resource: Current Research at SU : database of SU dissertations, recent titles available full text, 2008. http://wwwlib.umi.com/cr/syr/main.
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Ma, Hui. "Nanomaterials for Biological Applications: Drug Delivery and Bio-sensing." ScholarWorks@UNO, 2013. http://scholarworks.uno.edu/td/1647.
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The idea of utilizing nanomaterials in bio-related applications has been extensively practiced during the recent decades. Magnetic nanoparticles (MPs), especially superparamagnetic iron oxide nanoparticles have been demonstrated as promising candidates for biomedicine. A protective coating process with biocompatible materials is commonly performed on MPs to further enhance their colloidal and chemical stability in the physiological environment. Mesoporous hollow silica is another class of important nanomaterials that are extensively studied in drug delivery area for their ability to carry significant amount of guest molecules and release in a controlled manner.
In this study, different synthetic approaches that are able to produce hybrid nanomaterials, constituting both mesoporous hollow silica and magnetite nanoparticles, are described. In a two-step approach, pre-synthesized magnetite nanoparticles are either covalently conjugated to the surface of polystyrene beads and coated with silica or embedded/enclosed in the porous shell during a nanosized CaCO3 templated condensation of silica precursors, followed by acid dissolution to generate the hollow structure. It was demonstrated that the hollow interior is able to load large amount of hydrophobic drugs such as ibuprofen while the mesoporous shell is capable of prolonged drug. In order to simplify the fabrication procedure, a novel in-situ method is developed to coat silica surface with magnetite nanoparticles. By refluxing the iron precursor with mesoporous hollow silica nanospheres in polyamine/polyalcohol mixed media, one is able to directly form a high density layer of magnetite nanoparticles on silica surface during the synthesis, leaving reactive amine groups for further surface functionalization such as fluorescence conjugation. This approach provides a convenient synthesis for silica nanostructures with promising potential for drug delivery and multimodal imaging.
In addition to nanoparticles, nanowires also benefit the research and development of instruments in clinical diagnosis. Semiconductive nanowires have demonstrated their advantage in the fabrication of lab-on-a-chip devices to detect many charge carrying molecules such as antibody and DNA. In our study, In2O3 and silicon nanowire based field effect transistors were fabricated through bottom-up and top-down approaches, respectively, for ultrasensitive bio- detection of toxins such as ricin. The specific binding and non-specific interaction of nanowires with antibodies were also investigated.
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Clifford, Dustin M. "Non-Conventional Approaches to Syntheses of Ferromagnetic Nanomaterials." VCU Scholars Compass, 2016. http://scholarscompass.vcu.edu/etd/4205.
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The work of this dissertation is centered on two non-conventional synthetic approaches to ferromagnetic nanomaterials: high-throughput experimentation (HTE) (polyol process) and continuous flow (CF) synthesis (aqueous reduction and the polyol process). HTE was performed to investigate phase control between FexCo1-x and Co3-xFexOy. Exploration of synthesis limitations based on magnetic properties was achieved by reproducing Ms=210 emu/g. Morphological control of FexCo1-x alloy was achieved by formation of linear chains using an Hext. The final study of the FexCo1-x chains used DoE to determine factors to control FexCo1-x, diameter, crystallite size and morphology. [Ag] with [Metal] provide statistically significant control of crystallite size. [OH]/[Metal] predict 100 % FexCo1-x at > 30. To conclude section 1, a morphological study was performed on synthesis of Co3-xFexOy using the polyol process. Co3-xFexOy micropillars were synthesized at various sizes. The close proximity of the particles in the nanostructure produced an optical anisotropy and was magnetically induced which is evidence for the magneto-birefringence effect.
The second non-conventional synthetic approach involves continuous flow (CF) chemistry. Co nanoparticles (Ms=125 emu/g) were newly synthesized by aqueous reduction in a microreactor and had 30 ±10 nm diameter and were produced at >1g/hr, a marker of industrial-scale up viability. The final work was the CF synthesis of FexCo1-x. The FexCo1-x was synthesized with limitation to the composition. The maximum FexCo1-x phase composition at 20 % resulted from the aqueous carrier solvent triggering oxide formation over FexCo1-x.
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Huh, Seong. "Morphological Control of Multifunctional Mesoporous Silica Nanomaterials for Catalysis Applications." Ames, Iowa : Oak Ridge, Tenn. : Ames Laboratory ; distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy, 2004. http://www.osti.gov/servlets/purl/837271-xREJ4t/webviewable/.
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Thesis (Ph.D.); Submitted to Iowa State Univ., Ames, IA (US); 19 Dec 2004.Published through the Information Bridge: DOE Scientific and Technical Information. "IS-T 2397" Seong Huh. US Department of Energy 12/19/2004. Report is also available in paper and microfiche from NTIS.
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Korir, Daniel Kiplangat. "Design, Synthesis and Characterization of Polymer and Protein Coated Hybrid Nanomaterials: Investigation of Prototypes for Antimicrobial and Anticancer Applications." Thesis, University of North Texas, 2019. https://digital.library.unt.edu/ark:/67531/metadc1505197/.
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This work involves synthesis and characterization of isotropic and anisotropic noble metal nanoparticles for applications ranging from antimicrobial uses to anticancer applications. These nanomaterials are stabilized in genuinely benign biomaterials ranging from polymers to cross linked proteins for targeted cancer treatments. The nanoparticles are found to have tunable optical properties.
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Loch, Marius [Verfasser], Paolo [Akademischer Betreuer] Lugli, Paolo [Gutachter] Lugli, and Marc [Gutachter] Tornow. "Nanomaterials for hybrid organic-inorganic optoelectronic devices processed from solution / Marius Loch ; Gutachter: Paolo Lugli, Marc Tornow ; Betreuer: Paolo Lugli." München : Universitätsbibliothek der TU München, 2019. http://d-nb.info/1178672263/34.
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Parkinson, Patrick. "Ultrafast electronic processes at nanoscale organic-inorganic semiconductor interfaces." Thesis, University of Oxford, 2009. http://ora.ox.ac.uk/objects/uuid:e68168c6-bcc0-437d-9133-1bfaf955c80a.
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This thesis is concerned with the influence of nanoscale boundaries and interfaces upon the electronic processes that occur within both organic and inorganic semiconductors. Photoluminescent polymers, highly conducting polymers and nanoscale inorganic semiconductors have been investigated using state-of-the-art ultrafast optical techniques, to provide information on the sub-picosecond photoexcitation dynamics in these systems. The influence of dimensionality on the excitation transfer dynamics in a conjugated polymer blend is studied. Using time-resolved photoluminescence spectroscopy, the transfer transients both for a three-dimensional blend film, and for quasi-two-dimensional monolayers formed through intercalation of the polymer blend between the crystal planes of a SnS2 matrix have been measured. A comparison of the experimental data with a simple, dimensionality-dependent model is presented, based on point dipole electronic coupling between electronic transition moments. Within this approximation, the energy transfer dynamics are found to adopt a three-dimensional character in the solid film, and a two-dimensional nature in the monolayers present in the SnS2 -polymer nanocomposite. The time-resolved conductivity of isolated GaAs nanowires has been investigated by optical-pump terahertz-probe time-domain spectroscopy. The electronic response exhibits a pronounced surface plasmon mode that forms within 300 fs, before decaying within 10 ps as a result of charge trapping at the nanowire surface. The mobility has been extracted using the Drude model for a plasmon and is found to be remarkably high, being roughly one third of that typical for bulk GaAs at room-temperature and indicating the high quality and low bulk defect density in the nanowires studied. Finally, the time-resolved conductivity dynamics of photoexcited polymer-fullerene bulk heterojunction blends for two model polymers, P3HT and MDMO-PPV, blended with PCBM are presented. The observed terahertz-frequency conductivity is characteristic of dispersive charge transport for photoexcitation both at the π−π* absorption peak (560 nm for P3HT), and significantly below it (800 nm). The photoconductivity at 800 nm is unexpectedly high, which is attributed to the presence of a charge transfer complex. In addition, the excitation-fluence dependence of the photoconductivity is studied over more than four orders of magnitude. The time-averaged photoconductivity of the P3HT:PCBM blend is over 20 times larger than that of P3HT, indicating that long-lived positive polarons are responsible for the high photovoltaic efficiency of polymer:fullerene blends. At early times (~ ps) the linear dependence of photoconductivity upon fluence indicates that interfacial charge transfer dominates as an exciton decay pathway, generating charges with mobility of at least ~0.1cm2 V−1 s−1. At later times, a sub-linear relationship shows that carrier-carrier recombination effects influence the conductivity on a longer timescale (> 1 μs).
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Osborne, Rachel Delyth. "A Detailed Study of GCN4-Based Coiled-Coils, both In Vitro and In Silico, with Potential Applications in Responsive Bio-Inorganic Nanomaterials." Thesis, Imperial College London, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.505310.
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Yu, Lei. "DECONVOLVING THE STEPS TO CONTROL MORPHOLOGY, COMPOSITION, AND STRUCTURE, IN THE SYNTHESIS OF HIGH-ASPECT-RATIO METAL OXIDE NANOMATERIALS." UKnowledge, 2017. http://uknowledge.uky.edu/chemistry_etds/82.
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Metal oxides are of interest not only because of their huge abundance but also for their many applications such as for electrocatalysts, gas sensors, diodes, solar cells and lithium ion batteries (LIBs). Nano-sized metal oxides are especially desirable since they have larger surface-to-volume ratios advantageous for catalytic properties, and can display size and shape confinement properties such as magnetism. Thus, it is very important to explore the synthetic methods for these materials. It is essential, therefore, to understand the reaction mechanisms to create these materials, both on the nanoscale, and in real-time, to have design control of materials with desired morphologies and functions.
This dissertation covers both the design of new syntheses for nanomaterials, as well as real-time methods to understand their synthetic reaction mechanisms. It will focus on two parts: first, the synthesis of 1-dimension (1-D) featured nanomaterials, including manganese-containing spinel nanowires, and tin dioxide and zinc oxide-based negative nanowire arrays; and second, a mechanistic study of the synthetic reactions of nanomaterials using in situ transmission electron microscopy (TEM). The work presented here demonstrates unique synthetic routes to single crystalline “positive” and “negative” metal oxide nanowires, and introduces a new mechanism for the formation of single-crystalline hollow nanorods.
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Mercurio, James M. "Interlocked host structures for anion recognition and metal nanoparticles for catalysis and sensing applications." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:40178988-4945-4a98-af98-59a1a35a12d5.
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This thesis describes the synthesis and anion recognition properties of a variety of interlocked host receptors and the application of metal nanoparticles in the areas of catalysis and sensing. Chapter One introduces the field of anion supramolecular chemistry, with particular emphasis on areas relevant to the research discussed in later chapters. Following this, the synthesis and applications of metal nanoparticles are outlined. Chapter Two details the synthesis of a range of halo-triazolium based rotaxanes and explores the effects of altering both the halogen bond donor atom and degree of preorganisation on the anion recognition properties of the interlocked host system. A halogen bond containing catenane is also prepared and its anion binding properties investigated. Chapter Three initially reports the anion-templated synthesis of a series of neutral pyridine N-oxide axle containing rotaxanes before their ability to recognise anions in aqueous solvent mixtures is studied. Attempts to enhance anion binding through the incorporation of a positive charge into the macrocyclic component of the rotaxane structure are also explored. Chapter Four outlines the preparation of β-cyclodextrin functionalised metal nanoparticles and investigations of their catalytic and sensing properties. Chapter Five describes in detail the synthetic and analytical procedures discussed in chapters two to four. Chapter Six summarises the conclusions of this thesis.
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Zhang, Baofang. "Examination Of The Solution Behaviors Of The Giant Inorganic-Organic Amphiphilic Hybrids." University of Akron / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=akron1460369559.
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Huang, Wen-Yen. "Responsive theranostic nanoparticles." Thesis, University of Oxford, 2013. http://ora.ox.ac.uk/objects/uuid:275e12ca-e5a4-4f63-af9e-3c73948f8001.
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The development and use of nanotechnology towards theranostics (all-in-one disease diagnostics and therapeutic delivery) have been increasing in popularity in recent years, in particular the use of high capacity of nanomaterials to transport both imaging and therapeutic agents into pathological tissues or abnormal cells. In this work, biocompatible mesoporous silica nanoparticles (MSNs) that can be reliably endocytosed by cells are employed in the investigation of novel cancer treatment and magnetic resonance imaging (MRI). One of the principal aims is to develop T1 contrast nanoparticles not only with extraordinarily high MRI contrast characteristics, but also tunability through surface chemistry and functional protein conjugation. In coupling paramagnetic Gd3+-centres to MSNs, one can effectively marry the advantages afforded by increased molecular bulk with those engendered by confined water environment inside the porous network. Specifically, through exclusively biasing paramagnetic Gd3+-centres in the internal spaces of nanoparticles, their mobility and interaction with water protons can be altered, significantly, with beneficial changes in molecular tumbling (τR), proton exchange (τM) and water diffusion (τD) within relaxation dynamics. These MRI nanoparticles with internalised Gd3+-centres are additionally used in the development of tunable/responsive contrast agents through vectoring protein conjugation. The relaxivity of MSNs can be tailored depending on the separation distances between proteins and nanoparticles; significantly, the simultaneous retention of both high MRI contrast and protein vectoring is achieved by the insertion of long polyethylene glycol (PEG) chain. The image contrast can also be reversibly gated through the competitive displacement of surface proteins by their partner proteins. Specifically, these responsive nanoparticles possess a low contrast resulting from restricted water accessibility when protein moieties are conjugated on the particles, whereas the removal of proteins causes a transition of contrast from a low to high state. The MSNs synthesised in this work are used not only in diagnostic imaging but also in the delivery of therapeutic agents for cancer therapy. The agents can be either physically encapsulated inside the pores or chemically conjugated on the nanoparticles. For the former, their loading and release efficiencies are tunable by the electrostatic interactions with particle surface functional groups; while in the latter case, their retention on nanoparticles, as opposed to being released, plays an important role in the effectiveness of cancer treatment that is achieved by trigging programmed cell death (apoptosis) in this work. This nanoparticle conjugation secures the proteins’ activity by facilitating their bypass of proteolytic degradation. Significantly, specially designed nanoparticles that demonstrate endo/lysosomal escape capability can reliably deliver therapeutic cytochrome c to cell cytosols for the initiation of a caspase cascade within apoptosis with high efficacy.
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Yong, Chaw Keong. "Ultrafast carrier dynamics in organic-inorganic semiconductor nanostructures." Thesis, University of Oxford, 2012. http://ora.ox.ac.uk/objects/uuid:b2efdc6a-1531-4d3f-8af1-e3094747434c.
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This thesis is concerned with the influence of nanoscale boundaries and interfaces upon the electronic processes that occur within the inorganic semiconductors. Inorganic semiconductor nanowires and their blends with semiconducting polymers have been investigated using state-of-the-art ultrafast optical techniques to provide information on the sub-picosecond to nanosecond photoexcitation dynamics in these systems. Chapters 1 and 2 introduce the theory and background behind the work and present a literature review of previous work utilising nanowires in hybrid organic photovoltaic devices, revealing the performances to date. The experimental methods used during the thesis are detailed in Chapter 3. Chapter 4 describes the crucial roles of surface passivation on the ultrafast dynamics of exciton formation in gallium arsenide (GaAs) nanowires. By passivating the surface states of nanowires, exciton formation via the bimolecular conversion of electron-hole plasma can observed over few hundred picoseconds, in-contrast to the fast carrier trapping in 10 ps observed in the uncoated nanowires. Chapter 5 presents a novel method to passivate the surface-states of GaAs nanowires using semiconducting polymer. The carrier lifetime in the nanowires can be strongly enhanced when the ionization potential of the overcoated semiconducting polymer is smaller than the work function of the nanowires and the surface native oxide layers of nanowires are removed. Finally, Chapter 6 shows that the carrier cooling in the type-II wurtzite-zincblend InP nanowires is reduced by order-of magnitude during the spatial charge-transfer across the type-II heterojunction. The works decribed in this thesis reveals the crucial role of surface-states and bulk defects on the carrier dynamics of semiconductor nanowires. In-addition, a novel approach to passivate the surface defect states of nanowires using semiconducting polymers was developed.
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Kong, Liang. "Bismuth oxybromide-based photocatalysts for solar energy utilisation and environmental remediation." Thesis, University of Oxford, 2013. http://ora.ox.ac.uk/objects/uuid:c95ee3cc-b276-4c69-8b3f-eb60cc64e1c0.
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This thesis reports the investigation of Bismuth oxybromide (BiOBr) semiconductor material as an efficient photocatalyst for the sunlight harvesting as well as environmental cleanup. I have utilised different synthetic methodologies to obtain BiOBr and its derivatives, such as co-precipitation, ultrasonification, and photo-deposition; and have studied their structural and optical properties by X-ray diffraction and surface analysis techniques. I report the synthesis and characterisation of two new p-n heterojunction systems, AgBr-BiOBr and BiOBr-ZnFe2O4, and have performed initial studies on photocatalytic reaction and their catalytic decomposition mechanisms. I have also reported the surface modification method including the deposition of noble metal on BiOBr to investigate the role played by the noble metal and the interactions between semiconductor and metal using various characterisation measurements. Furthermore, a continuous series of BiOBr-BiOI solid solutions were synthesised, characterised and the photocatalytic degradation was performed on the as-obtained semiconductors, to study the band structure properties of the solid solutions.
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Ballentine, Michael Drake. "Imidazolium Ionic Liquids as Multifunctional Solvents, Ligands, and Reducing Agents for Noble Metal Deposition onto Well-Defined Heterostructures and the Effect of Synthetic History on Catalytic Performance." TopSCHOLAR®, 2018. https://digitalcommons.wku.edu/theses/2101.
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1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([BMIM]Tf2N) was investigated as a multifunctional solvent, ligand, and reducing agent for platinum deposition onto well-defined CdSe@CdS nanorods. Platinum deposition was carried out thermally and photochemically using Pt(acac)2 as the metal precursor. Thermal deposition was investigated in [BMIM]Tf2N with and without addition of a sacrificial reducing agent, and product topology was compared with the products obtained from polyol reduction using 1,2-hexadecanediol, oleic acid, and oleylamine in diphenyl ether. Photochemically induced platinum deposition was carried out at room temperature in [BMIM]Tf2N, and product topology was compared with the photodeposition products obtained from a toluene dispersion. Thermal deposition of platinum in ionic liquid showed rods of broken morphology and small platinum nanoparticles speckled across the rods’ surface, while photodeposition of platinum exhibited particles decorated throughout the nanorod surface but larger in size than those exhibited by thermal means. Photocatalytic
reduction of methylene blue was studied using these Pt-CdSe@CdS heterostructured nanoparticles, and catalytic performance was correlated with topology and synthetic history. Initial findings of catalytic performance suggest that there in an advantage of depositing platinum nanoparticles onto the CdSe@CdS in the ionic liquid system. Methylene blue dye was degraded using each system and the results show and there is an increased performance of the nanorods synthesized in the ionic system.
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Woolerton, Thomas William. "Development of enzymatic H2 production and CO2 reduction systems." Thesis, University of Oxford, 2012. http://ora.ox.ac.uk/objects/uuid:393741ac-94b1-4d56-b680-d9a434db77e2.
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One of today’s most pressing scientific challenges is the conception, development and deployment of renewable energy technologies that will meet the demands of a rapidly increasing population. The motivation is not only dwindling fossil fuel reserves, but also the necessary curtailment of emissions of the greenhouse gas carbon dioxide (a product of burning fossil fuels). The sun provides a vast amount of energy (120,000 TW globally), and one major challenge is the conversion of a fraction of this energy into chemical energy, thereby allowing it to be stored. Dihydrogen (H₂) that is produced from water is an attractive candidate to store solar energy (a ‘solar fuel’), as are high energy carbon-containing molecules (such as CO) that are formed directly from carbon dioxide. One key aspect is the development of catalysts that are able to offer high rates and efficiencies. In biology, some microbes acquire energy from the metabolism of H₂ and CO. The biological catalysts - enzymes - that are responsible are hydrogenases (for the oxidation of H₂ to protons); and carbon monoxide dehydrogenases (CODHs, for the oxidation of CO to CO₂). These redox enzymes, containing nickel and iron as the only metals, are extraordinary in terms of their catalytic characteristics: many are fully reversible catalysts and offer very high turnover frequencies (thousands per second are common), with only tiny energy input requirements. This Thesis uses a hydrogenase from the bacterium Escherichia coli, and two CODHs from the bacterium Carboxydothermus hydrogenoformans, as the catalysts in H2 production and CO₂ reduction systems. Chapter 3 describes the concept and development not of a solar fuel system, but of a device that catalyses the water-gas shift reaction (the reaction between CO and water to form H₂ and CO₂) - a process of major industrial importance for the production of high purity H₂. Chapters 4, 5 and 6 detail photochemical CO₂ reduction systems that are driven by visible light. These systems, operating under mild, aqueous conditions, involve CODHs attached either to TiO₂ nanoparticles that are sensitised to visible light by the co-attachment of a ruthenium-based dye complex, or to cadmium sulfide nanomaterials that, having a narrow band gap, are inherently photoexcitable by visible light. The motivation here is not the construction of technological devices; indeed, the enzymes that are used are fragile, highly sensitive to oxygen, and impossible to scale to industrial levels. Rather, the drivers are those of scientific curiosity (can the incorporation of these remarkable biological catalysts enable the creation of outstanding solar fuel devices?), and of producing systems that serve as benchmarks and inspiration for the development of fully synthetic systems that are robust and scalable.
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Uddin, I. "Bioinspired inorganic nanomaterial synthesis and its applications." Thesis(Ph.D.), CSIR-National Chemical Laboratory, Pune, 2011. http://dspace.ncl.res.in:8080/xmlui/handle/20.500.12252/3821.
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Pryor, Donald Edward. "Synthesis and Bioactivity Studies of Nanoparticles Based on Simple Inorganic and Coordination Gallium Compounds as Cellular Delivering Vehicles of Ga(III) Ions for Potential Therapeutic Applications." Kent State University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=kent1543554532063877.
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Jones, Simon Philip. "Influence of modifiers on Palladium based nanoparticles for room temperature formic acid decomposition." Thesis, University of Oxford, 2013. http://ora.ox.ac.uk/objects/uuid:873277f2-c4f7-45b7-a16d-bba064e24bee.
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Heterogeneous catalysts form a highly important part of everyday life, ranging from the production of fertiliser enabling the growth of crops that sustain much of the world's population to the production of synthetic fuels. They constitute a key part of the chemical industry and contribute towards substantial economic and environmental benefits. Heterogeneous catalysts are also believed to have an important role to play in a future hydrogen economy, reducing our requirements for fossil fuels. To this end, formic acid has been proposed as a potential hydrogen storage material for small portable devices. Additionally, formic acid has historically been used as a probe molecule to study catalyst materials and recent developments in the knowledge of its decomposition pathways and the preferred sites of these reactions, establish a good foundation for further study. This work explores a range of novel modification techniques that alter the activity of Pd nanoparticles to decompose formic acid to H2 and CO2. The methods used are the addition of polymers, attaching various functional groups to the surface of the catalyst support and decoration of nanoparticles with sub-monolayer coverages of another metal. Using a range of characterisation methods including FTIR of an adsorbed CO probe, XRD and XPS coupled with computational modelling, it is found that these methods result in some significant electronic and/or geometric alterations to the Pd nanoparticles. For polymer modification, the nature of the pendent group is highly important in determining the effects of the polymer on the Pd particles, with all the tested polymers resulting in varying degrees of electronic donation to the Pd surface. The geometric modifications caused by the polymers also varied with pendent groups; with amine containing pendent groups found to selectively block low coordinate sites, preventing the undesired dehydration of formic acid which results in poisoning of the Pd catalyst by the resulting CO. Attachment of amine groups to the surface of metal oxide catalyst supports, is demonstrated to result in dramatic electronic promotional effects to the supported Pd nanoparticles, and when an amine polymer is attached to the support surface the geometric modification is again observed. Finally decoration of Pd nanoparticles with a sub-monolayer coverage of a second metal is examined, resulting in some similar electronic and geometric effects on Pd nanoparticle surfaces to those observed with polymer modification with corresponding changes in formic acid decomposition activity. Overall, a number of methods are displayed to tune the catalytic activity and selectivity of Pd nanoparticles for formic acid decomposition, resulting in catalysts with some of the highest reported TOF's at room temperature. These modification methods are believed to be potentially applicable to a wide range of other catalytic reactions that operate under mild conditions.
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Maggio, Mario. "Carbon-based nanomaterials." Doctoral thesis, Universita degli studi di Salerno, 2017. http://hdl.handle.net/10556/2482.
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2014 - 2015New layered carbon-based materials were prepared and exhaustively characterized exploiting different characterization techniques, such as thermogravimetry (TGA), differential thermal calorimetry (DSC), Fourier transform infrared (FTIR) and wide angle X-ray diffraction (WAXD). Pristine graphite (G) with high surface area and carbon black (CB) samples with different surface areas were selected as starting materials to prepare the corresponding oxidized samples, i.e. graphite oxide (GO) and carbon black oxide (oCB), with the Hummers’ method. Thanks to the strong hydrophilicity and to the lamellar structure of oxidized carbon-based materials, a rich intercalation chemistry is permitted. In fact, after treatments of GO and oCB by strong basis, ordered intercalation compounds have been obtained, not only if the starting material is crystalline like graphite oxide, but also if it is completely amorphous like oxidized carbon black. Starting basified GO, free-standing papers can be obtained by vacuum filtration, as well as by casting procedure, of colloidal dispersions of graphene oxide sheets. The use of basified GO leads to more flexible, solvent resistant and thermally stable GO papers. Spectroscopic analyses of the obtained papers have been conducted aiming to a possible rationalization of the observed behavior. [edited by author]
Per questo lavoro di tesi di dottorato, sono stati preparati nuovi nanomateriali basti su carbonio ed esaustivamente caratterizzati con tecniche quali termogravimetria (TGA), calorimetria a scansione differenziale (DSC), spettroscopia infrarossa (FT-IR) e diffrazione dei razzi X (WAXD). I materiali di partenza utilizzati per questo lavoro di tesi, sono stati la grafite ad alta area superficiale e carbon black con differenti valori di area superficiale, al fine di ottenere i corrispondenti materiali ossidati quali ossido di grafite (GO) e carbon black ossidato (oCB). Il metodo utilizzato per le ossidazioni dei suddetti starting materials è quello di Hummers. Grazie alla forte idrofilicità ed alla struttura lamellare posseduta dai materiali carboniosi ossidati, è possibile ottenere svariati composti di intercalazione trattando il GO (cristallino) e l’oCB(amorfo) con basi forti e con conseguente funzionalizzazione ionica con cationi di natura organica. Inoltre, partendo da dispersioni di GO basificato, sono stati ottenuti fogli di ossido di grafite e di grafene mediante filtrazione e/o per lenta evaporazione del solvente. Utilizzando una base nella procedura di ottenimento dei cosiddetti fogli di ossido di grafite/grafene, sono stati preparati campioni free-standing con elevata flessibilità, resistenza ai solventi e alle alte temperature. [a cura dell'autore]
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