Tesis sobre el tema "Sol-gel Synthesi"
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Pohl, Annika. "Sol−Gel Synthesis of CMR Manganites". Doctoral thesis, Uppsala University, Department of Materials Chemistry, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-3970.
Texto completoThe development of more advanced materials forms the basis of technological progress. One group of fascinating compounds with many potential applications in spintronic devices are the mixed-valence perovskite manganites. These have attracted considerable interest during the last decade through their very large magnetoresistance near the Curie Temperature. Although the properties of a material determinie any application, the development of reliable and flexible synthesis methods is crucial, as is the understanding of these methods. Knowledge of how different materials are formed is also of general importance in tailoring new materials. The aim of this project has therefore been not only to develop a new synthesis route, but also to understand the mechanisms involved.
This thesis describes the synthesis and characterization of a novel manganese alkoxide and its use in sol–gel processing of magnetoresistive perovskite manganites. In searching for a soluble manganese alkoxide for sol–gel processing, we found that the methoxy-ethoxide, [Mn19O12(moe)14(moeH)10]·moeH, has a high solubility in appropriate organic solvents. Being 1.65 nm across, it is one of the largest alkoxides reported; it is also of interest because of its (for oxo-alkoxides) rare planar structure. After mixing with La, Nd, Ca, Sr, and Ba methoxy-ethoxides, [Mn19O12(moe)14(moeH)10]·moeH was used in the first purely alkoxide based sol–gel processing of perovskites manganites. The phase evolution on heating xerogel powders to 1000°C was studied, and thin films were prepared by spin-coating.
It was found that the easily oxidised Mn-alkoxide facilitates the formation of high oxygen-excess modifications of the perovskites. The reactive precursor system yields fully hydrolysed gels almost without organic residues, but the gel absorbs CO2 from the air, leading to carbonate formation. The carbonate decomposition is the limiting step in oxide formation. Transport measurements of La0.67Ca0.33MnO3 films on LaAlO3 substrate show that all-alkoxide sol–gel derived films can compete with PLD films in terms of quality of epitaxy and transport. The somewhat different behaviour of the sol–gel derived films compared to PLD films is attributed to differences in morphology and oxygen stoichiometry.
Mogili, Sravya. "Sol-Gel Synthesis of Aluminosilicate Glasses". Thesis, Southern Illinois University at Edwardsville, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=1584733.
Texto completoThe main goal of this research project is to synthesize aluminosilicate glass materials that are doped with praseodymium. To be useful for optical studies, these glass materials must be optically transparent, strong enough to be handled and polished, and free of cracks. An advantage of the sol-gel process is that we have control over the amount of doping. However, a disadvantage of the sol-gel process is that cracking often occurs during the drying step.
Meegan, Jonathan E. "Sol gel synthesis of organised matter". Thesis, University of Leeds, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.417746.
Texto completoKarg, Matthias. "Fluorolytische Sol-Gel-Synthese von Magnesiumfluorid". Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät, 2015. http://dx.doi.org/10.18452/17292.
Texto completoThe present Ph.D. thesis deals with mechanistic investigations of the fluorolytic sol-gel synthesis of nano magnesium fluoride. Furthermore, variations of the well known synthesis are introduced. The aim of these variations is to tailor the properties of the synthesized materials. The thesis covers three main chapters briefly introduced below: The course of the fluorolysis of magnesium methoxide with methanolic HF-solution will be monitored for six months using 19F NMR spectroscopy. The existence of MgF2 nanoparticles and agglomerates of disturbed MgF2 particles will be proven. It is demonstrated that hydrogen fluoride does not react immediately after the addition of HF-solution. For the first time MAS-NMR experiments of sols will be conducted. Furthermore, stepwise fluorolysis of magnesium chloride will be followed by NMR spectroscopy and X-ray diffraction. In this case no intermediates will be detected. Three different synthetic approaches capable of tailoring the crystallite and particle sizes will be presented. Using a sequential synthesis leads to increased size of the agglomerates in the sols. It will be demonstrated that heating and refluxing of a sol increases the crystallite size slightly. Solvothermal synthesis will be the last method leading to significant increase in crystallite sizes. Several synthetic parameters will be varied to identify their influence on the received crystallites. The influence of nano MgF2 on the crystallisation of amorphous TiO2 is investigated. It will be shown, that the sol-gel synthesis of TiO2 in the presence of a MgF2 sol leads to the crystallisation of the rutile polymorph of TiO2. The temperature treatment for that is comparatively low and just 5 mol% MgF2 are necessary. Furthermore, a different alternative synthesis will be introduced, that gives the anatase polymorph at the same conditions. Eventually a possible mechanism for the structural induction is proposed.
Kapusuz, Derya. "Sol-gel Synthesis Of Dna Encapsulated Silica". Master's thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/2/12610627/index.pdf.
Texto completoSibottier, Emilie. "Génération électro-assistée de films à base de silice : fonctionnalisation, mésostructuration et applications analytiques". Thesis, Nancy 1, 2007. http://www.theses.fr/2007NAN10101/document.
Texto completoThe study deals with various aspects of a novel method of sol-gel synthesis : the electro-assisted generation of functionalized and/or mesostructured silica thin films, and their applications in analytical electrochemistry. Sol-gel-derived silica films functionnalized with amine or thiol groups have been electrogenerated on gold electrodes. The formation of a partial self-assembled monolayer of mercaptopropyltrimethoxysilane (MPTMS) on gold led to a silica film adhering well to the electrode surface owing to the MPTMS acting as a « molecular glue ». The whole process was characterized by two successive distinct rates, starting by a slow deposition stage leading to thin deposits, which was followed by a much faster film growing in the form of macroporous coatings. The use of these modified electrodes was considered as a voltammetric sensor for copper(II). By adding a surfactant in the synthesis medium, it’s possible to electrogenerate mesostructured silica films with hexagonal structure with pore channels oriented perpendiculary to the substrate (which is difficult to get by other methods). The electrochemically-induced-self-assembly of surfactant-templated silica thin films can be applied to various conducting supports. The broad interest of the novel method was demonstrated by its ability to produce homogeneous deposits of silica on non-planar surfaces or heterogeneous substrates, what is difficult by the traditional techniques of film deposition. Finally, a preliminary approach has been proposed in order to apply the electrodeposition process coupled with a scanning electrochemical microscope in order to get localized sol-gel deposits at the micrometric size level on gold
Thakor, Vikalp Amar Peng Zhonghua. "Syntheses and sol-gel polymerizations of organotriethoxysilanes". Diss., UMK access, 2005.
Buscar texto completo"A thesis in chemistry." Typescript. Advisor: Zhonghua Peng. Vita. Title from "catalog record" of the print edition Description based on contents viewed June 27, 2006. Includes bibliographical references (leaves 79-85). Online version of the print edition.
Bheemala, Veera Manesh. "Sol-Gel Synthesis of Lanthanide-Doped Aluminosilicate Glasses". Thesis, Southern Illinois University at Edwardsville, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=1601351.
Texto completoDoping Praseodymium into Al-Si glass has potential applications in permanent holographic data storage and other optical devices. For this we are using the sol-gel method to produce glass monoliths at relatively low temperatures. The silicon precursor is tetraethylorthosilicate (TEOS) and aluminum tri-sec butoxide (ATSB) is the aluminum precursor. TEOS is hydrolyzed in ethanol with HCl as a catalyst. ATSB is then added, as well as praseodymium chloride in water. To prevent cracking we use dimethyl formamide (DMF) as a drying control chemical additive (DCCA). The solution is poured into a polymethylpentene cylinder and maintained at 40°C and the temperature is raised to 150°C to dry and shrink the sample. Samples prepared by this method are amorphous, as indicated by X-ray diffraction. The final aim of this research is to produce optically clear, fracture less monoliths by varying aging, shape and drying conditions.
Yakovlev, A. V. y A. V. Vinogradov. "Inkjetready Sol-gel Synthesis of Nanocrystalline Titania Colloids". Thesis, Sumy State University, 2015. http://essuir.sumdu.edu.ua/handle/123456789/42582.
Texto completoKaur, Rajvinder. "Non-hydrolytic Sol-gel Synthesis of Tin Sulfides". University of Toledo / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1404243055.
Texto completoWuttke, Stefan. "Sol-Gel-Synthese und Charakterisierung nanoskopischer Magnesiumfluorid-Phasen". Berlin mbv, Mensch-und-Buch-Verl, 2009. http://d-nb.info/995893306/04.
Texto completoSchiavon, Giovanni. "Sol-gel derived nanocomposites synthesis, spectroscopy, atomic force microscopy /". [S.l. : s.n.], 2000. http://deposit.ddb.de/cgi-bin/dokserv?idn=962035424.
Texto completoČižauskaitė, Sigutė. "Sol-gel synthesis of perovskite structure aluminates and cobaltates". Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2009. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2009~D_20091202_112230-17664.
Texto completoŠiame darbe vienfazis perovskito struktūros gadolinio aliuminatas GdAlO3 zolių-gelių metodu buvo gautas 1000 oC temperatūroje, gadolinio jonų šaltiniu naudojant Gd2O3, kompleksus sudarančiu reagentu – 1,2 etandiolį, natūralią vyno rūgštį, citrinų rūgštį arba citrinų rūgšties ir etanolamino mišinį. Sintetinant GdAlO3, gautų tyrimų rezultatai parodė, kaip yra svarbu zolių gelių procese pasirinkti tinkamas pradines medžiagas bei kompleksus su metalais sudarančius reagentus: gadolinio jonų šaltiniu naudojant Gd2O3 buvo gauti geresni rezultatai nei naudojant Gd(NO3)3•6H2O, vienfazis GdAlO3 gali būti sėkmingai susintetintas kompleksus sudarančiu reagentu naudojant tiek natūralią vyno rūgštį, tiek 1,2 etandiolį, tiek citrinų rūgštį, tiek citrinų rūgšties ir etanolamino mišinį. Nustatyta, kad sintetinant stronciu pakeistus gadolinio aliuminatus Gd1–xSrxAlO3– (x = 0,10, 0,25, 0,50, 0,75), tinkamesnis gadolinio jonų šaltinis yra gadolinio oksidas nei gadolinio nitratas heksahidratas, kompleksus sudarantis reagentas – EDTA nei natūrali vyno rūgštis. Vienfazis perovskito struktūros stronciu pakeistas gadolinio aliuminatas Gd0,90Sr0,10AlO3– buvo susintetintas zolių-gelių metodu 1000 oC temperatūroje, gadolinio jonų šaltiniu naudojant Gd2O3, stroncio jonų šaltiniu – Sr(NO3)2, kompleksus sudarančiu reagentu – EDTA. Be to, 800 ºC iškaitinimo temperatūra yra per maža šiems junginiams sintetinti. Pirmą kartą pasiūlytas vandeninis zolių gelių metodas lantano ir gadolinio kobaltatams... [toliau žr. visą tekstą]
Dubnikova, Natalija. "Sol-gel synthesis and characterization of lanthanide aluminium garnets". Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2011. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2011~D_20111227_092034-78155.
Texto completoPažangių medžiagų bei technologijų kūrimas ir taikymas - tai labai svarbus šiandieninės informacinės visuomenės uždavinys. Granato kristalinės struktūros medžiagos, pasižymėdamos ypatingomis fizikinėmis bei cheminėmis savybėmis, yra plačiai naudojamos informacinių technologijų, kietafazių lazerių, optikos įrenginių gamybose, medicinos įrangose, bei daugelyje kitų sričių. Todėl jos dėl savo unikalių savybių ir plačiai tebetyrinėjamos iki šiol. Šiame darbe pirmą kartą buvo susintetinti Ce-Al-O, Pr-Al-O, Nd-Al-O, Tb-Al-O, Dy-Al-O, Ho-Al-O, Er-Al-O, Tm-Al-O, Yb-Al-O, Lu-Al-O, Y(Nd)-Al-O ir Y(Sm)-Al-O acetatiniai-nitratiniai-glikoliatiniai geliai zolių-gelių metodu vandeniniuose tirpaluose. Jie buvo panaudoti pradinėmis medžiagomis atitinkamų lantanoidų aliuminio granatų sintezei. Vienfaziai terbio aliuminio granatas (Tb3Al5O12), disprozio aliuminio granatas (Dy3Al5O12), holmio aliuminio granatas (Ho3Al5O12), erbio aliuminio granatas (Er3Al5O12), tulio aliuminio granatas (Tm3Al5O12), iterbio aliuminio granatas (Yb3Al5O12) ir liutecio aliuminio granatas (Lu3Al5O12) buvo gauti, terbio jonų šaltiniu naudojant terbio oksidą, disprozio – disprozio oksidą, holmio – holmio oksidą, erbio – erbio oksidą, tulio – tulio oksidą, iterbio – iterbio oksidą, lutecio – liutecio oksidą, kompleksus sudarančiu reagentu 1,2-etandiolį. Tyrimų rezultatai parodė, kad šių lantanoidų aliuminio granatai gauti santykinai žemoje temperatūroje (1000°C). Zolių-gelių metodu sintetinant cerio aliuminio granatą... [toliau žr. visą tekstą]
Sparks, Andrew William 1977. "Sol-gel synthesis of one-dimensional photonic bandgap structures". Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/9557.
Texto completoIncludes bibliographical references (p. 26-27).
A series of one-dimensional photonic bandgap devices were fabricated using SiO2 and TiO2 films deposited from solution by the sol-gel method. A dielectric mirror, or broadband interference filter, was fabricated by alternating quarter-wave optical thickness layers of the two films on a silicon substrate for a total of six layer pairs. This device exhibited an omnidirectional photonic bandgap of 450 nm in TE-polarization and 110 nm in TM-polarization. A microcavity, or narrowband filter, was fabricated with a TiO2 Fabry-Perot cavity sandwiched between two mirrors of three layer pairs each. The resonant cavity corresponded to a wavelength of roughly 1500 nm and shifted to shorter wavelengths with increasing incident angles. A maximum resonant quality factor of 11. 7 was achieved.
by Andrew William Sparks.
S.B.
Rane, Neelesh Janardan. "Sol-Gel Synthesis and Characterization of Mesoporous Ceria Membranes". University of Cincinnati / OhioLINK, 2003. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1046381173.
Texto completoEltanany, Gehan. "Sol-gel synthesis and properties of nanoscopic aluminum fluoride". Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2007. http://dx.doi.org/10.18452/15679.
Texto completoAluminum fluoride (HS-AlF3) prepared via sol-gel synthesis route under non-aqueous conditions exhibits high surface area and an extremely strong Lewis acidity, comparable with some of the strongest known Lewis acids such as SbF5 and ACF. The basis of its unusual properties is the sol-gel fluorination of aluminum alkoxide with anhydrous HF in organic solvents yielding first an amorphous catalytically inactive precursor with high surface area, which can be dried and eventually post-fluorinated to get HS-AlF3. In this thesis, all steps of the synthesis route were thoroughly investigated. The results of these investigations together with detailed analysis of the obtained materials are reported and discussed. HS-AlF3 supported on Al2O3 with different HS-AlF3 loadings was prepared by wet impregnation method. The properties of the HS-AlF3/Al2O3 samples as Lewis acid catalyst were evaluated for CHClF2 dismutation and CBrF2CBrFCF3 isomerization. The preparation of AlFyOx via sol-gel method is also reported. AlFyOx prepared is amorphous and have high surface are up to 240 m2/g.
Walker, Jeremy D. "Exploring the Synthesis and Characterization of Nanoenergetic Materials from Sol-Gel Chemistry". Diss., Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/14573.
Texto completoForoutan, F. "Sol-gel synthesis of phosphate-based glasses for biomedical applications". Thesis, University College London (University of London), 2015. http://discovery.ucl.ac.uk/1470766/.
Texto completoBogdanoviciene, I., A. Kareiva, M. Misevicius, L. Bauermeistere, A. Viksna, K. A. Gross y A. Beganskiene. "Sol-Gel Synthesis and Characterization of Cerium Substituted Calcium Hydroxyapatite". Thesis, Sumy State University, 2012. http://essuir.sumdu.edu.ua/handle/123456789/34936.
Texto completoKabre, Tushar Shriram. "Co3O4 Thin Films: Sol-Gel Synthesis, Electrocatalytic Properties & Photoelectrochemistry". The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1316552072.
Texto completoLiao, Haidong. "Sol-gel Synthesis and Photocatalytic Characterization of Immobilized TiO2 Films". Licentiate thesis, Stockholm : Skolan för kemivetenskap, Kungliga Tekniska högskolan, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-10683.
Texto completoNewport, Anne Christine. "The sol-gel synthesis of anti-Stokes luminescent glass materials". Thesis, University of Greenwich, 2000. http://gala.gre.ac.uk/6257/.
Texto completoBROUDIC, JEAN-CHARLES. "Syntheses et caracterisation de cordierites obtenues par voie sol-gel". Université Louis Pasteur (Strasbourg) (1971-2008), 1989. http://www.theses.fr/1989STR13116.
Texto completoBelon, Cindy. "Synthèse de revêtements hybrides organique-inorganique par photopolymérisation sol-gel". Thesis, Mulhouse, 2010. http://www.theses.fr/2010MULH3908.
Texto completoThe present work questioned the interest of sol-gel photopolymerization as a novel route to synthesize nanocomposite films from hybrid mono- and bis-silylated precursors. The potentialities of this process that is based on a catalysis promoted by photogenerated Bronsted superacids have been poorly investigated so far. Depending on the precursor nature, the sol-gel photopolymerization was possibly combined with an organic photopolymerization in a view to generate the dual crosslinking of the organic and inorganic networks in a single step. A first aspect of this work concemed the structural properties of the hybrid films: Fourier transformed IR spectroscopy, 29Si and 13C solid state Nuclear Magnetic Resonance spectroscopy and X-rays analysis were thus implemented. These experiments highlighted the numerous advantages of the photoinduced sol-gel process: its high reactivity, its living character, the absence of water or solvent and the local organization in the resulting films. Finally, the thermo-mechanical properties of the UV cured materials were assessed by using a wide range of characterization techniques: dynamic mechanical analysis, differentia!scanning calorimetry, nanoindentation, tribological and scratch tests. The effect of the organic moiety functionality of the precursors was thus evidenced and relationships between microstructure and properties ofthe hybrid films were established
Chowdhury, Anirban. "Synthesis and Characterisation of Ferroelectric Thin Films via Sol-Gel Routes". Thesis, University of Leeds, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.505084.
Texto completoMalek, Mohamad Zahid Abdul. "Synthesis, processing and characterisation of photochromic dye doped sol-gel materials". Thesis, University of Sheffield, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310760.
Texto completoO'Callaghan, Samantha Ann. "Sol-gel synthesis of nanosized sodium potassium niobate-based piezoelectric ceramics". Thesis, University of Cambridge, 2014. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.707999.
Texto completoVarcoe, John Robert. "Synthesis and characterisation of novel inorganic polymer electrolytes". Thesis, University of Exeter, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.302667.
Texto completoCasanova, Martínez Ana. "Synthetic strategies for the preparation of nanoporous carbons with improved electrical conductivity". Thesis, Orléans, 2020. http://www.theses.fr/2020ORLE3093.
Texto completoNanoporous carbons are key materials in many electrochemical applications over a wide variety of competitors (such as noble metals, non-noble metals or metal oxides) due to the diversity of materials with controlled pore architectures combined with adequate properties; particularly, chemical and mechanical stability, biocompatibility, rich surface chemistry and, most importantly, relatively high electronic conductivity.Although some carbons (e.g., graphite, graphene) present electronic properties close to those of metallic electrodes, this feature depends strongly on the spatial arrangement of the carbon atoms. Indeed, most nanoporous carbons are non-polycrystalline materials with a low degree of structural order and, as a consequence, with limited conductivity. Thus, efforts are yet needed to prepare nanoporous carbons with high and well defined pore architectures combining high electrical conductivity without compromising the porous structure.To increase the conductivity of nanoporous carbon electrodes without compromising the porosity, several strategies have been explored such as: (i) heteroatoms’ doping; (ii) coating with a conductive phase; (iii) synthesizing 3D nanoporous graphene-like architectures, and (iv) incorporating a conductive additive in the formulation of carbon electrodes inks. The latter is the common practice for the manufacturing of the electrodes in electrochemical applications, being carbon black the most popular conductive additive.The approach in this PhD consisted in exploring various synthetic approaches to obtain nanoporous carbons with high porous networks and enhanced conductivity upon incorporating various carbon nanostructures as conductive additives. In a first approach, the additive was incorporated during the synthesis of the nanoporous carbon material itself, rather than as percolator in the inks typically used in the preparation of electrodes (e.g., carbon material, binder and percolator). In a second approach, 3D nanoporous graphene-like architectures were obtained by hydrothermal approaches.The synthesis of the nanoporous carbons was carried out by a modification of the polycondensation of resorcinol and formaldehyde mixtures well reported in the literature for the preparation of carbon gels. This approach allows obtaining highly porous materials with tuneable properties compared to conventional activation methods that usually render materials with broad pore size distributions. To overcome the drawback of their low electrical conductivity, various carbon nanostructures were used as conductive additives: carbon black, graphite, graphene and graphene oxide derivatives.The effect of various parameters such as the type, amount, hydrophobic/hydrophilic character and composition of the additive was explored. The study revealed the important role of the nature of the additive not only on the conductivity of the carbon gel/additive composite, but also on the development of the porosity during the synthesis. Carbon additives of hydrophobic nature act as a porogen, favouring the development of multimodal pore architectures, with predominance of large mesopores. Hydrophilic additives rendered materials with lower porosity. Regarding conductivity, the composites showed enhanced values, with percolation thresholds of ca. 8 wt.% for carbon black.In the second approach, various nanostructured carbons were subjected to a hydrothermal treatment. First, graphene synthesis by plasma decomposition of ethanol was optimized, with good production rates and quality for flows of 2-4 g/h. Graphene oxide was also synthesized by a modified Hummers method. The hydrothermal treatment rendered materials with improved porosity.Overall, highly nanoporous carbons with controlled mesopore architectures and enhanced conductivity were obtained. Such materials are of interest as electrodes in electrochemical applications (e.g, energy storage, supercapacitors, electrochemical sensors)
Didier, Benoît. "Synthèse d'un matériau hybride polyimide/silice par voie sol-gel : Etude structure/propriétés". Chambéry, 2005. http://www.theses.fr/2005CHAMS022.
Texto completoThis work consisted to synthesize a hybrid material polyimide/silica by sol-gel process. The preparation of these materials has a problem of compatibility between the phases organic and inorganic. Silica and polymer do not have particular affinity and tend to create strong phase segregation. To avoid this phenomenon several solutions were reported ln the literature, like the use of coupling agent. In our case, we reduced this phenomenon by creating covalent bonds between polyimide and silica. For that, we fixed along the backbone of polyimide some functions alkoxysilanes which are reactive with silica functions. These functions will react with silica during the sol-gel process. We varied various parameters such as the grafting rate between polymer and silica, or catalyst used at the time of the sol-gel process. The continuation of work consisted in studying the various morphologies obtained according to the evolution of the parameters of synthesis. For that, we used various techniques such as the thermogravimetric analysis, the determination of density, the infra-red spectroscopy, or microscopy. This work enabled us to determine the silica rates, the size of the particles within the matrix and their state of dispersion. We also studied the microstructure of our materials per dynamic mechanical spectroscopy. Indeed, different morphologies have various effects on the reinforcement of silica. We thus could identify phenomena of percolation for some of our materials. In a last time, we studied the properties of gas permeation of our materials, in order to draw the great evolutions from the coefficients of permeability and selectivity according to the silica rate and from the rate of grafting between the organic and inorganic phase. We thus showed that the introduction of silica and the grafting of this one with polymer conducted to materials less permeable, but generally more selective
Roux, Richard. "Synthèse de phase stationnaires monolithiques de silice hybrides pour les techniques séparatives miniaturisées". Thesis, Lyon 1, 2009. http://www.theses.fr/2009LYO10208.
Texto completoThis manuscript is dedicated to the synthesis (via sol-gel process) and caracterization of hybrid monolithic silica for miniaturized separation techniques : nano-liquid chromatography (nano-LC), capillary electrochromatography (CEC) and microchips. The bibliography part deals with the recent axis of development of these separatives techniques : increase of efficiency per time unit, increase of peak capacity and miniaturisation of these techniques. After an overview of this evolution, the manuscript is focused on the silica monolithic stationnary phases. Finally, a detailed study on the different kinds of protocol fonctionnalization of these silica monoliths highlights the advantage of simplifying the synthesis using a single step protocol (« one pot »). The experimental part is also focused on this kind of single step protocol so as to synthesize hybrid silica monoliths dedicated to the reversed phase mode in chromatography. First, the synthesis of hybrid C3 silica monoliths shows the ability to synthesize a functionnalized silica monolith via a single step sol gel process (« one pot »). Then, this kind of process is used and optimized in order to synthesize a hybrid C8 silica monolithic into capillaries. These stationary phases allowed reaching performances similar to those synthesized in two steps (sol-gel process and grafting) and to the particulate columns (5 μm)
Martin, Julie. "Design and direct synthesis of peptide-branched polysiloxane. Towards new generation of hybrid biomaterials". Thesis, Montpellier, 2019. http://www.theses.fr/2019MONTS093.
Texto completoThe purpose of this PhD work was the design and synthesis of new hybrid biomaterials based on a polysiloxane backbone. To do so, several biomolecules were silylated, in order to be incorporated in a multifunctional silicone backbone by a bottom-up strategy. Indeed, in contrast to post-grafting approaches, we set up the direct copolymerization of hybrid biomolecule macromonomers presenting a methyldihydroxysilyl moiety, with the dichlorodimethylsilane (DCDMS). Different types of biomolecules have been silylated: peptides, drugs and imaging probes, each of them affording specific properties to the final bioorganic silicone material. Three main applications are described: (i) the design and synthesis of bioactive PDMS cross-linked materials, (ii) silicone-based nanoparticules (NPs) and (iii) silicone-based polyplexes. PDMS materials with biological properties, either antimicrobial or cell adhesion, were obtained by copolymerization of hybrid peptide macromonomer with DCDMS, vinyl and silane reagents followed by hydrosilylation. Silicone-based NPs resulted from the introduction of several hydrophilic macromonomers at 0.5 to 1 mol% compared to DCDMS. Hybrid peptide ligands targeting cancer cell receptors, PEG and a drug model (Methotrexate) were prepared and copolymerized. At last, we investigated the preparation of siRNA polyplexes involving LysHis-based hybrid peptide macromonomers by an in situ polymerization method
Le, Bail Nicolas. "Conception, synthèse par chimie douce et caractérisation de revêtements sol-gel hybrides multifonctionnels sur polycarbonate". Thesis, Ecully, Ecole centrale de Lyon, 2015. http://www.theses.fr/2015ECDL0040/document.
Texto completoThe polycarbonate is a widespread polymer material, highly appreciated for its low density, its transparency and its good mechanical properties. This material is used for divert applications (automotive, medical, optical...) and is very competitive in terms of quality and prices. However, it displays some weaknesses, essentially due to its poor abrasion and scratch resistance and its possible degradation under UV or hydrolysis. In this context, the PhD aim is to design and develop a new hybrid organic / inorganic protective coating with silica and zirconia based precursors prepared by the sol gel process, which allow a curing compatible with the polycarbonate's Tg (148°C). Here, it is discussed on the solutions retained to obtain a scratch resistant, hydrophobic and transparent coating. It is showed that, scratch resistant protective coatings can be deposited on pristine PC thanks to a performing hybrid organic / inorganic coating by modulating its bulk properties. Moreover, results demonstrate the key role played by a phenylsilane precursor in enhancing the adherence. Nanoindentation, scratch-test, NMR and FTIR analysis will be discussed
Morigi, Francesca. "A green approach to mesoporous silica particles synthesis by sol-gel chemistry". Master's thesis, Alma Mater Studiorum - Università di Bologna, 2017. http://amslaurea.unibo.it/13434/.
Texto completoTan, Bing. "Controlled synthesis and functionalization of nanoporous sol-gel silica particles and gels". Lexington, Ky. : [University of Kentucky Libraries], 2005. http://lib.uky.edu/ETD/ukychen2005d00329/etd.pdf.
Texto completoTitle from document title page (viewed on November 2, 2005). Document formatted into pages; contains xix, 336 p. : ill. Includes abstract and vita. Includes bibliographical references (p. 331-334).
Wiener, Matthias. "Synthese und Charakterisierung Sol-Gel-basierter Kohlenstoff-Materialien für die Hochtemperatur-Wärmedämmung". kostenfrei, 2009. http://www.opus-bayern.de/uni-wuerzburg/volltexte/2010/4424/.
Texto completoRaval, Hema M. "Non-hydrolytic sol-gel synthesis of inorganic oxides and organic-inorganic hybrids". Thesis, University of Surrey, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.326496.
Texto completoCheikh, Ibrahim Ajfane. "Synthèse des matériaux hybrides organiques inorganiques multifonctionnalisés". Thesis, Montpellier 2, 2012. http://www.theses.fr/2012MON20067/document.
Texto completoThe aim of this work was focused on the structuration and the functionalization of organic-inorganic hybrid materials by the sol-gel process.The synthesis and characterization of new proton conductive membranes for fuel cell proton exchange membrane (PMFC), was prepared in the first part. Hybrid membranes based on polyethylene glycol highly functionalized with sulfonic acid have been synthesized and characterized through a physicochemical and proton conductivity. They have good mechanical properties, a sufficient chemical stability and a performant proton conductivity to be used as an electrolyte in fuel cell proton exchange membrane.In the second part, we have developed hybrid mesoporous materials with porous multifunctionalized in the presence of surfactant nonionic block copolymer (P123). Two probes were used for this study: the proton exchange capacity and the control of the growth of gold nanoparticles in the pores
Gossard, Alban. "Synthèse d'oxydes par voie sol-gel colloïdale : application aux précurseurs de combustibles nucléaires". Thesis, Montpellier, Ecole nationale supérieure de chimie, 2014. http://www.theses.fr/2014ENCM0010/document.
Texto completoOne of the main objectives for the future nuclear fuel cycle is the recycling of the minor actinides. Different options are considered: their integration into a new fuel for a prospect of a closed fuel cycle or their transmutation in order to significantly decrease the long-term radiotoxicity of ultimate wastes. In both cases, the synthesis of new advanced materials integrating the actinides jointly is required.Sol-gel processes allow the organization of the material at the colloidal scale or the insertion of controlled porosity using « templates ». Furthermore, the possibility to work in a « wet environment » prevents the formation of pulverulent powders which are contaminant in the case of materials incorporating radioactive elements. The main purpose of this work is to demonstrate the adaptability of this route to the nuclear field.Firstly, a methodology of synthesis from a colloidal sol-gel route was set up on a non-radioactive zirconium-based system in order to characterize and understand of the different mechanisms of this synthesis. Then, studies on shaping, including insertion of porosity, were performed. Zirconia monoliths have been obtained thanks to a coupling between a colloidal sol-gel process and the formation of an emulsion stabilized by clusters of solid particles. Finally, a transposition of this work to an uranium-based system was introduced, pointing out different promising perspectives specially concerning the possibilities of shaping of the final material
Puy, Guillaume. "Synthèse et caractérisation de phases stationnaires monolithiques de silice pour les techniques séparatives miniaturisées". Lyon 1, 2006. http://www.theses.fr/2006LYO10282.
Texto completoGrund, Silke. "Synthese anorganisch-organischer Polyfurfurylalkohol-Nanokomposite durch die Zwillingspolymerisation". Doctoral thesis, Universitätsbibliothek Chemnitz, 2011. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-63440.
Texto completoMisso, Ágatha Matos. "Síntese e caracterização de fósforos a base de silicatos de cálcio e magnésio dopados com európio e disprósio". Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/85/85134/tde-10042017-143712/.
Texto completoCa and Mg silicates based phosphors were prepared by sol-gel method combined with the molten salts process. The gel of silica was obtained from Na2SiO3 solution by using europium, dysprosium, calcium and magnesium chloride solutions. Therefore, those chlorides were homogenously dispersed into the gel. The obtained gel was dried and heat treated to 900° C for 1h to allow the fusion of the present salts. Then it was water washed until negative test for Cl-, and dried. The reduction of the europium to Eu2+ was performed under atmosphere of 5% of H2 and 95% of Ar to 900° C for 3h, to reach CaMgSi2O6:Eu2+ and CaMgSi2O6:Eu2+:Dy3+ phosphors. Diopside was identified as main crystalline phase and quartz, as secondary phase from XRD (X-ray diffraction) patterns. SEM (scanning electron microscopy) micrographs, of the samples showed needles, spheres, leaves and rods of particles and agglomerates. Thermal analysis (TGA-DTGA) curves revealed that the crystallization temperature of CaMgSi2O6:Eu2+ lies around 765° C. Photoluminescence spectroscopy of the phosphors was studied based on interconfigurational 4fN → 4fN-1 5d transition of Eu2+ ion. The spectra of excitation showed 4fN → 4fN-1 5d transition of Eu2+ ion broad band, related to the ligand to metal charge transfer transition (LMCT) O2- (2p) → Eu3+ in the 250 nm region, when the emission is monitored at 583,5 nm. It also presents the 4f ↔ 4f transitions of Eu3+ ion bands, showing the 7F0 → 5L6 transition at 393 nm. From emission spectra with excitation monitored at 393 nm, it can be observed fine peaks between 570 and 750 nm which are characteristics of 5D0 7FJ (J = 0 - 5) transition of Eu3+ ion, indicating that the Eu3+ ion occupies a site with center of inversion. Finally, the obtained results indicate that the developed method is suitable to synthesize CaMgSi2O6:Eu2+ and CaMgSi2O6:Eu2+:Dy3+ phosphors, as it has been proposed.
Cristini-Robbe, Odile. "Synthèse de poudres céramiques conductrices par procédé sol-gel assisté par du Co2 supercritique : étude des caractéristiques morphologiques, structurales et électriques". Montpellier 2, 2003. http://www.theses.fr/2003MON20195.
Texto completoBieri, Fabian. "Sol-Gel Synthese von Vanadiumoxid-Nanoröhren und Eisenoxidnanopartikeln sowie deren Charakterisierung und Mikrostrukturierung /". [S.l.] : [s.n.], 2003. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=15301.
Texto completoMatsuoka, Jun. "STUDIES ON SOL-GEL SYNTHESIS AND PROPERTIES OF GOLD MICROCRYSTAL-DOPED OXIDE FILMS". Kyoto University, 1998. http://hdl.handle.net/2433/157042.
Texto completoKyoto University (京都大学)
0048
新制・論文博士
博士(工学)
乙第9845号
論工博第3335号
新制||工||1116(附属図書館)
UT51-98-G444
(主査)教授 曾我 直弘, 教授 小久保 正, 教授 横尾 俊信
学位規則第4条第2項該当
ZNAIDI, LAMINA. "Synthese des bronzes de vanadium pour procedes sol-gel : caracterisation structurale et proprietes". Paris 6, 1989. http://www.theses.fr/1989PA066530.
Texto completoDi, Giampaolo Anna Rita. "Elaboration de cordierite a basse temperature : synthese par voie sol-gel et densification". Limoges, 1987. http://www.theses.fr/1987LIMOA034.
Texto completoIn, Martin. "Chimie des procedes sol-gel appliquee a la synthese de copolymeres organiques-inorganiques". Paris 6, 1994. http://www.theses.fr/1994PA066154.
Texto completoZhou, Xiuquan. "Non-hydrolytic Sol-gel (NHSG) Synthesis of Transition Metal Sulfides and Theoretical Investigations". University of Toledo / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1365030696.
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