Teses / dissertações sobre o tema "Silica films"
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Campbell-Rance, Debbie. "Electrodeposited Silica Thin Films". VCU Scholars Compass, 2010. http://scholarscompass.vcu.edu/etd/2123.
Texto completo da fonteSpaargaren, Susan Marianne Rosemary. "Radiation effects on silica based waveguides". Thesis, Imperial College London, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.267942.
Texto completo da fonteKlichko, Yaroslav Vladimirovich. "Functional mesoporous silica films for nanosystems applications". Diss., Restricted to subscribing institutions, 2009. http://proquest.umi.com/pqdweb?did=1998520791&sid=1&Fmt=2&clientId=1564&RQT=309&VName=PQD.
Texto completo da fonteKokan, Julie Runyan. "Processing of low permittivity silica thin films". Thesis, Georgia Institute of Technology, 1994. http://hdl.handle.net/1853/20032.
Texto completo da fonteGeite, Patrik. "Medical Implant Applications of Mesoporous Silica Films". Thesis, Linköpings universitet, Nanostrukturerade material, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-154463.
Texto completo da fonteWooten, Mary K. "NANOFILTRATION MEMBRANES FROM ORIENTED MESOPOROUS SILICA THIN FILMS". UKnowledge, 2014. http://uknowledge.uky.edu/cme_etds/28.
Texto completo da fonteBragg, Donald. "Photocatalytic Oxidation of Carbon Monoxide Using Sputter Deposited Molybdenum Oxide Thin Films on a Silicon Dioxide Substrate". Fogler Library, University of Maine, 2007. http://www.library.umaine.edu/theses/pdf/BraggD2007.pdf.
Texto completo da fonteBasnig, Deomila. "Élaboration de films minces de silice pour des applications en chimie analytique". Electronic Thesis or Diss., Université de Lorraine, 2021. http://www.theses.fr/2021LORR0102.
Texto completo da fonteOriented mesoporous silica-based film on FTO electrode was prepared via electrochemically-assisted self-assembly approach (EASA). A potential of -1.5V was applied to the FTO electrode containing a prehydrolyzed silica precursor, (e.g. tetraethyl orthosilicate), in the presence of a template (e.g. cetrimonium bromide) and electrolyte. This approach could generate vertically-aligned silica nanochannels with pore sizes adjustable between 2 and 3 nm, depending on the template. This work showed the voltammetric behavior and the selectivity of the mesoporous silica film towards various positively-charged cations of different nature, size, and charge. Results showed an accumulation and selectivity favoring the least positive charged ion: MB⁺ > PQ²⁺ > DQ²⁺ > Ru(bpy)₃²⁺ > Ru(NH₃)₆³⁺. The enhancement of the voltammetric signals relative to the bare FTO electrode was strongly dependent on the probe type. The accumulation of the different redox probe is attributed to the due to the vertical orientation of the nanochannel favoring fast transport and diffusion unto the electrode surface. Further electrochemical characterization showed an interplay of the suface-controlled and diffusion-controlled process, wherein adsorbed species is more prominent in diluted media. Results showed that changing the debye length and electrokinetic radius of the silica nanochannel due to the ionic strength or nanochannel diameter also affects the transport and electrochemical detection of the paraquat analyte. Mesoporous silica films having different pore size, prepared using different alkyl ammonium bromide as template, yield different sensitivities, which could be due to the difference in electrochemical charge of the silica surface, as well as the distribution of ions in the nanochannel. Finally, an attempt to modify the surface of silica wall using zirconia was also made to study the transport of cations, which could pave a way for an improved stability of the mesoporous film
CHAKRAVARTY, SRINIVAS L. N. "DEVELOPMENT OF SCRATCH RESISTANT PECVD SILICA-LIKE FILMS". University of Cincinnati / OhioLINK, 2000. http://rave.ohiolink.edu/etdc/view?acc_num=ucin973542599.
Texto completo da fonteMoskowitz, Steven. "Atomic force miscroscopy [sic] study of SiO₂/Si(111)--(7x7) grown via atomic oxygen plasma /". Thesis, Connect to this title online; UW restricted, 2005. http://hdl.handle.net/1773/11556.
Texto completo da fonteSawtell, David Arthur Gregory. "Plasma enhanced chemical vapour deposition of silica thin films". Thesis, University of Manchester, 2011. https://www.research.manchester.ac.uk/portal/en/theses/plasma-enhanced-chemical-vapour-deposition-of-silica-thin-films(2c75bbd8-8d89-42f2-b926-b464e619b4aa).html.
Texto completo da fonteSteinthal, Michael Gregory 1964. "Laser densification of sol-gel-derived silica coatings". Thesis, The University of Arizona, 1989. http://hdl.handle.net/10150/277183.
Texto completo da fonteYang, Hong. "Forms of mesoporous silica, fibers, films, curved shapes and patterns". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape10/PQDD_0006/NQ41535.pdf.
Texto completo da fonteMaCarthy, Orla. "Selective area doping of porous silica films for optical applications". Thesis, Imperial College London, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.299318.
Texto completo da fonteAbbas, Bassam. "Linear and nonlinear optical phenomena in thin sol-gel organic-inorganic films". Thesis, University of Reading, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.298744.
Texto completo da fonteDe, Witt Joanna Christine. "Switching the reflection in chiral nematic mesoporous silica and organosilica films". Thesis, University of British Columbia, 2012. http://hdl.handle.net/2429/43781.
Texto completo da fonteRobertson, Joseph William F. "Fabrication, analysis and patterning of sol-gel based silica ultrathin films". Diss., The University of Arizona, 2004. http://hdl.handle.net/10150/280795.
Texto completo da fonteGhaffari, Kasra. "Optical interferometric measurement of in-plane residual stresses in SiO₂ films on silicon substrates". Diss., Georgia Institute of Technology, 1995. http://hdl.handle.net/1853/16815.
Texto completo da fonteDe, Paz-Simon Héloise. "Sol-gel photopolymerization of inorganic precursors and application for mesoporous silica films elaboration". Thesis, Mulhouse, 2013. http://www.theses.fr/2013MULH6112/document.
Texto completo da fonteWhereas sol-gel process has been extensively studied almost no papers concerning photoinduced sol-gel process subsists. This later is based on in situ generation of acids or basics species able of initiating hydrolysis and condensation reactions happening on sol-gel process. This photoinduced alternative is particularly adapted for preparation of thin films and has lots of advantages such as photolatent, stable, solvent and water free initial formulation along with faster reaction rates. In one hand, from simple inorganic precursors, a kinetic and mechanistic study of the photoacid-catalyzed sol-gel reactions was realized. Then, we attempt to define what chemical, physical and photochemical parameters determine the precise sequence, kinetics and advancement of these reactions under different processing conditions Furthermore, an equivalent photobase-catalyzed sol-gel process has been also studied thoroughly. In a second hand, we focus on application of this photoinduced process for the preparation of mesoporous silica films. A triblock copolymer surfactant was added to the initial inorganic precursor. Feasibility of this photochemical approach from water and solvent free formulation was first investigated and mesoporous films were obtained. Then, we work on understanding the two interdependent mechanisms: surfactant self-assembly and inorganic network condensation. The system was after that optimized in order to have a precise control of pore size and structure. Finally, the last point involves organic photodegradation in order to liberate porosity
Mårtensson, Niklas. "Optical Properties of Silica-Copper Oxide Thin Films Prepared by Spin Coating". Thesis, Linköpings universitet, Tillämpad optik, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-71188.
Texto completo da fonteBjörk, Emma M. "Mesoporous Building Blocks : Synthesis and Characterization of Mesoporous Silica Particles and Films". Doctoral thesis, Linköpings universitet, Nanostrukturerade material, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-99858.
Texto completo da fonteWAGH, VIJAY HEMANT. "VAPOR PHASE SILANATION OF PLASMA-POLYMERIZED SILICA-LIKE FILMS BY 3-AMINOPROPYLTRIETHOXYSILANE". University of Cincinnati / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1121884987.
Texto completo da fonteTURNER, ROBERT HAINES. "MOLECULAR STRUCTURE OF INTERFACES FORMED WITH PLASMA POLYMERIZED SILICA-LIKE PRIMER FILMS". University of Cincinnati / OhioLINK, 2001. http://rave.ohiolink.edu/etdc/view?acc_num=ucin997298644.
Texto completo da fonteYe, Fangmao. "Single molecule studies of meso/macro porous silica materials and gradient films". Diss., Manhattan, Kan. : Kansas State University, 2009. http://hdl.handle.net/2097/1699.
Texto completo da fonteLeuty, Gary Martin. "Structure and Dynamics of Fluoromethane Films Adsorbed on Graphite and Silica Substrates". OpenSIUC, 2010. https://opensiuc.lib.siu.edu/theses/402.
Texto completo da fonteMotos, Blanca. "Silices fonctionnalisées contenant des espèces ioniques pour la catalyse hétérogène". Thesis, Montpellier, Ecole nationale supérieure de chimie, 2011. http://www.theses.fr/2011ENCM0015.
Texto completo da fonteHeterogenous catalysis is an area in continuous development due to economical, health and environmental issues. This thesis deals with the preparation of i-silica materials for the posterior application in heterogeneous catalysis. First, di-aryl imidazolium containing silica materials were synthesized by post-grafting reactions on mesoporous SBA-15. Moreover, di-alkyl imidazolium containing PMO films were prepared in presence of an anionic surfactant. Then, supported copper and palladium N-heterocyclic carbenes were synthesized from di-aryl imidazolium silica and applied to A3 reactions (Cu-NHC) and Suzuki cross-coupling reactions (Pd-NHC). Imidazolium functionalized silicas were also utilized as heterogeneous organocatalysts in Henry reactions and in reactions of cycloaddition of carbon dioxide to epoxides. Finally, PMO type materials containing amine/ammonium and zwitterionic substructures were applied to Henry and Biginelli organocatalysed reactions, respectively
Kang, Laeugu. "Study of HFO₂ as a future gate dielectric and implementation of polysilicon electrodes for HFO₂ films /". Full text (PDF) from UMI/Dissertation Abstracts International, 2000. http://wwwlib.umi.com/cr/utexas/fullcit?p3004301.
Texto completo da fonteCao, Yuanmei. "Antireflective Polyimide Based Films". University of Akron / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=akron1335501090.
Texto completo da fonteLORENZI, ROBERTO. "Silica based functional materials: - Charge transport in nanostructured SnO2: SiO2 thin films. - Second harmonic generation in niobium potassium silicate glasses. - Tapered silica optical microfibres for gas sensors". Doctoral thesis, Università degli Studi di Milano-Bicocca, 2010. http://hdl.handle.net/10281/10933.
Texto completo da fonteYilmaz, Emre. "Sensitization Of Sol-gel Derived Titania-silica Photocatalytic Thin Films With Ascorbic Acid". Master's thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12614226/index.pdf.
Texto completo da fonteKorkmaz, Erdural Beril. "Photocatalytic Antimicrobial And Self-cleaning Properties Of Titania-silica Mixed Oxide Thin Films". Phd thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12615137/index.pdf.
Texto completo da fonteTaylor, Mark Philip. "Studies of the reaction of silane and hydrogen peroxide forming silica thin films". Thesis, University of Bristol, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.337161.
Texto completo da fonteMoloney, John, Thomas McDermott, Taslima Akter, Michael McCann, J. M. Donal MacElroy, Damian A. Mooney e Denis P. Dowling. "Molecular simulation of the fabrication and permselective characterisation of thin nanoporous silica films". Diffusion fundamentals 16 (2011) 21, S. 1-3, 2011. https://ul.qucosa.de/id/qucosa%3A13753.
Texto completo da fonteHudgins, Robert Anthony. "Photonic Applications of Rare Earth Doped TEOS Based Silica Thin Films and Waveguides". University of Cincinnati / OhioLINK, 2003. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1054758007.
Texto completo da fonteMoloney, John, Thomas McDermott, Taslima Akter, Michael McCann, J. M. Donal MacElroy, Damian A. Mooney e Denis P. Dowling. "Molecular simulation of the fabrication and permselective characterisation of thin nanoporous silica films". Universitätsbibliothek Leipzig, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-184768.
Texto completo da fonteSyme, Derric Benjamin. "Microfabrication and Characterization of Freestanding and Integrated Carbon Nanotube Thin Films". BYU ScholarsArchive, 2019. https://scholarsarchive.byu.edu/etd/7376.
Texto completo da fonteHeineman, Dawn Laurel. "Optimization of ALD grown titania thin films for the infiltration of silica photonic crystals". Thesis, Available online, Georgia Institute of Technology, 2004:, 2004. http://etd.gatech.edu/theses/available/etd-05142004-143254/unrestricted/heineman%5Fdawn%5Fl%5F200407%5Fms.pdf.
Texto completo da fonteSummers, Christopher, Committee Chair ; Snyder, Robert, Committee Member ; Wang, Zhong Lin, Committee Member. Includes bibliographical references.
Fuhrich, Alexander Benedikt [Verfasser]. "Ultra-thin Germania and Germania-Silica films : Growth, structure and reactivity / Alexander Benedikt Fuhrich". Berlin : Freie Universität Berlin, 2019. http://d-nb.info/1199937002/34.
Texto completo da fonteOblitas, Torrico Ruben Felipe Arturo [UNESP]. "Preparação e caracterização de híbridos orgânico-inorgânicos à base de epoxí-silica". Universidade Estadual Paulista (UNESP), 2016. http://hdl.handle.net/11449/139461.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Este projeto visa a investigar a relação entre a estrutura e as propriedades dos materiais epoxi-silica preparados pelo método sol-gel. Os híbridos foram preparados pela reação de cura entre o poly(Bisphenol A-co-epichlorohydrin) (DGBEA) , e o dietil triamina (DETA) assim como pelo processo Sol-Gel de hidrolise e condensação entre GPTMS (3-Glycidoxypropyl)methyldiethoxysilane) e TEOS. Ressonância magnética nuclear (RMN), espectroscopia de fotoelétrons de raios X (XPS), espalhamento de raios X a baixo ângulo (SAXS), espectroscopia de Infravermelho e RAMAN, microscopia de força atômica (AFM) assim como termogravimétria foram utilizadas com o proposito de investigar a morfologia e as propriedades estruturais do material. Finalmente as propriedades anticorrosivas dos filmes foram testadas em uma solução salina por meio de espectroscopia de impedância eletroquímica (EIS). Durante a fase inicial do projeto diferentes amostras com diferentes concentrações de TEOS foram preparadas. A estabilidade térmica como as propriedades anticorrosivas foram testadas. Os resultados mostraram que para maiores concentrações de TEOS, as propriedades anticorrosivas e térmicas dos híbridos melhoram significativamente. Vários resultados interessantes foram obtidos, para híbridos com razoes molares de TEOS : GPTMS : DGBEA = 1 : 1: 1, tendo módulos de impedância de até 1010 Ω cm-2. Durante a segunda fase do projeto, duas series de amostras com concentrações diferentes de GPTMS a TEOS foram preparadas. As propriedades estruturais foram obtidas por meio de Espectroscopia Infravermelho, Raman, RMN e XPS e espalhamento de raios X a baixo ângulo. A hidrofobicidade assim como as propriedades térmicas foram avaliadas por meio de testes de molhabilidade e análise termogravimétrica. Finalmente as propriedades anticorrosivas dos filmes em contato com solução salina foram testadas por meio de espectroscopia de impedância electroquímica.
This work aims to investigate the relationship between the structure and the properties of the sol-gel prepared epoxy-silica materials. The organic-inorganic hybrids were prepared from the curing reaction of poly(Bisphenol A-co-epichlorohydrin) (DGBEA), with Diethyltriamine (DETA) and (3-Glycidoxypropyl)methyltriethoxysilane) (GPTMS) combined with the sol-gel hydrolysis and condensation reactions between Tetraethoxysilane (TEOS) and GPTMS. Nuclear magnetic resonance (NMR), X-ray photoelectron spectroscopy (XPS), Infrared and Raman spectroscopy (IR), Atomic force microscopy, as well as thermogravimetry (TG) have been used with the purpose to investigate the morphological and structural properties of the material. Finally the anticorrosive properties of the hybrid coated carbon steel were evaluated in saline solution using electrochemical impedance spectroscopy (EIS). During the initial phase of the project different samples with increasing concentrations of TEOS have been prepared and their thermal stability as well as their anticorrosive properties were tested. It was found, that for increasing TEOS concentration, the hybrid’s anticorrosive and thermal properties can be improved. Several interesting results were obtained for hybrid coatings at a TEOS : GPTMS : DGBEA = 1 : 1 : 1 ratio, having an impedance modulus of up to 1010 Ω cm-2. During the second phase of the work, a series of epoxy-silica hybrids were synthetized varying the concentrations of GPTMS and TEOS. Their structural properties were characterized by means of Infrared, Raman, solid NMR and XPS spectroscopy. Their hydrophobicity as well as their thermal resistance were evaluated using the drop shape analysis and thermogravimetry. Finally the anticorrosive properties of the coatings in saline solution were tested using electrochemical impedance spectroscopy.
Eker, Zeynep. "Preparation And Characterization Of Titania-silica-gold Thin Films Over Ito Substrates For Laccase Immobilization". Master's thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/3/12611022/index.pdf.
Texto completo da fonteg/ml solution at 4°
C for 2 hours. Laccase activity decreased after 4 hours of impregnation in enzyme solution. Laccase leakage was observed in the first usage of substrates and 55% activity decrease was determined in the subsequent use which might be attributed to the presence of uncovalently adsorbed enzyme on the fresh samples. In air and in buffer storage stabilities were also tested. It was found that the activity of samples almost vanished after 6 days regardless of storage conditions. Both enzymes had more activity on ITO substrate.
BENGU, BASAK. "THE MOLECULAR STRUCTURE OF INTERFACES FORMED BETWEEN PLASMA POLYMERIZED SILICA-LIKE FILMS AND EPOXY ADHESIVES". University of Cincinnati / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1195657609.
Texto completo da fonteLi, Xin. "MULTISCALE DYNAMIC MONTE CARLO / CONTINUUM MODELING OF DRYING AND CURING IN SOL-GEL SILICA FILMS". Lexington, Ky. : [University of Kentucky Libraries], 2008. http://hdl.handle.net/10225/950.
Texto completo da fonteTitle from document title page (viewed on December 11, 2008). Document formatted into pages; contains: xii, 143 p. : ill. (some col.). Includes abstract and vita. Includes bibliographical references (p. 137-142).
Boffelli, Marco <1987>. "Defects related cathodoluminescence of N-doped silica thin films prepared by radio frequency magnetron sputtering". Master's Degree Thesis, Università Ca' Foscari Venezia, 2012. http://hdl.handle.net/10579/1703.
Texto completo da fonteLewandowski, Adrián Leandro. "The Atomic Structure of Ultrathin Germania Films". Doctoral thesis, Humboldt-Universität zu Berlin, 2019. http://dx.doi.org/10.18452/20874.
Texto completo da fonteThe preparation of metal-supported ultrathin films of germanium dioxide, termed also germania, has been successfully achieved for the first time. The structure of the films is elucidated with atomic precision and chemical sensitivity using surface science techniques. The investigation is performed by analyzing STM images and is complemented by low-energy electron diffraction (LEED) patterns, a dynamical LEED study, and external support from density functional theory (DFT) calculations. In this work, we compare side-by-side atomically-resolved scanning tunneling microscopy (STM) images of ultrathin films of germania and silica. The analysis aims to investigate the impact of the metal support on the structure of oxide films. For that purpose, ultrathin germania films are grown on Ru(0001), Pt(111) and Au(111), and compared with previously reported silica ultrathin films supported on different substrates. Germania has been widely associated with silica since they are considered to be structural and chemical equivalent materials. Three main network structures have been characterized: monolayer, zigzag and bilayer films. In all systems, the building block consists of a distorted tetrahedron with a germanium atom surrounded by four oxygen atoms. Adjacent tetrahedra connect to each other through Ge-O-Ge bonds and, in the case of the monolayer films, they also bind to the metal support. Conversely, in bilayer films there are no chemical bonds to the metal substrate, thus providing more flexibility to the film structure. Through a meticulous control of the preparation conditions one can obtain a purely crystalline phase, an amorphous one, or one with intermediate order. It is important to highlight that the amorphous germania bilayer film represents a new 2-dimensional amorphous material.
Foster, Evan Wayne. "Self-assembly of extended, high-density gold nanoparticle monolayers on silicon dioxide /". view abstract or download file of text, 2006. http://proquest.umi.com/pqdweb?did=1188875831&sid=1&Fmt=2&clientId=11238&RQT=309&VName=PQD.
Texto completo da fonteTypescript. Includes vita and abstract. Includes bibliographical references (leaves 173-182). Also available for download via the World Wide Web; free to University of Oregon users.
Del, Campo Menoyo Javier. "Compatibilisation of polyimide-silica ceramers and interfacial interactions with carbon fibres in high-temperature matrix composites". Thesis, Loughborough University, 1997. https://dspace.lboro.ac.uk/2134/27080.
Texto completo da fonteKaya, Sarp. "Structural and catalytic investigations on vanadium oxide nanoparticles supported on silica films grown an a Mo(112) substrate". Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2007. http://dx.doi.org/10.18452/15639.
Texto completo da fonteThe widespread use of model systems for understanding the heterogeneous catalytic processes is based on bridging the structural complexity gap between present generation of supported metal and metal oxide technical catalysts and crystalline metal and planar metal/oxide systems, which are utilized to investigate structure-reactivity relationships by a large variety of surface science techniques. In this thesis, we focused on a concept of so-called ''monolayer'' vanadium oxide catalysts, which have been introduced particularly for methanol oxidation reactions. Following a bottom-up approach, silica supported vanadium oxide model catalysts were investigated. Combining a number of experimental techniques, the surface of Mo(112) used as a substrate for the silica films was characterized in detail and the atomic structure of the silica film was determined. Adsorption of water and growth of vanadium oxide nanoparticles on the silica films, and finally the reactivity of vanadium oxide/silica systems towards methanol were studied. In contrast to the previously suggested models, an oxygen induced p(2×3) superstructure formed on a Mo(112) surface should be considered as one dimensional surface oxide where Mo=O groups are formed preferentially along the [-1-11] direction of the Mo(112) surface. Monolayer silica films grown on Mo(112) surfaces are composed of two-dimensional network of SiO4 tetrahedra. Depending on the film preparation conditions, the structure can be altered by additional oxygen atoms adsorbed on the Mo substrate. The defect structure includes antiphase domain boundaries which form by a half-lattice shift along the [-110] direction and a low density of point defects, most probably silicon vacancies. Water does not dissociate on the monolayer silica film. An ordered structure of water with respect to silica film was observed at 140 K owing to good lattice matching between the silica film and hexagonal ice. Amorphous solid water layers homogenously covering the surface at 100 K were used as reactive layers for vanadium oxide particles in order to mimic ''wet chemistry'' used in preparation of technical catalysts. The results revealed that ice layer assisted the formation of hydrated vanadium oxide nanoparticles partially terminated by V=O and V-OH groups. The dehydration takes place above 500 K, thus exposing V-terminated surface. Methanol dissociates on dehydrated vanadium oxide particles and methoxy species are stable on the surface up to 500 K only in the presence of vanadium terminated surface sites. Formaldehyde production which takes place at ~550 K is strongly affected by the surface structure of the vanadium oxide particles and exhibits a maximum at specific ratio between V- and V=O sites on the surface. The results presented may have a strong impact on our understanding of the catalytic reactions at the molecular level.
Guillemin, Yann. "Électrogénération sol-gel de films minces siliceux mésostructurés : méthylation, variations structurales, contrôle morphologique et microlithographie". Thesis, Université de Lorraine, 2012. http://www.theses.fr/2012LORR0249/document.
Texto completo da fonteThanks to an Electro-Assisted Self-Assembly (EASA) cooperative process, the sol-gel electrogeneration of silica thin films from sols containing alkoxysilanes and cationic surfactant molecules (cetyltrimethylammonium: CTAB) allows to obtain mesostructured films exhibiting mesopore channels orthogonal to the substrate. Organized methylated silica thin films with "vertically"-aligned mesopores were electrogenerated by performing a one-step co-condensation between alkoxysilanes and organo-alkoxysilanes in the presence of CTAB. Monitoring mass transport issues inside these thin layers demonstrates that their permeability can be modulated by the -CH3 moieties ratio. The EASA process was then extended to the use of mainly aqueous sols. This permits the electrogeneration of new structures, the control of the porous network orientation and a modulation of the deposited material morphology by changing the CTA+ counter-anion. Various synthesis strategies aiming at increasing the porosity of electrogenerated films were evaluated (use of swelling agents and a triblock copolymer). Some convincing results dealing with the electrogeneration of silica films exhibiting a hierarchical porosity (combination of mesopores with macropores) are also presented. Finally, the last part of this work demonstrates how the EASA process can be applied at the local scale (micrometric) by using a scanning electrochemical microscope as a synthesis tool, thus opening the way to the sol-gel electromicrolithography
hung, chien chi, e 簡吉鴻. "Silica、Zirconia and Zirconium Silicate Thin Films Prepared by Magnetron Sputtering". Thesis, 2001. http://ndltd.ncl.edu.tw/handle/85817605148903407982.
Texto completo da fonte國立東華大學
材料科學與工程研究所
89
The developments of future gate oxide of MOS device for ULSI technology and next-generation capacitor of DRAM devices for memory storage require new dielectric materials. There is significant interest in using ZrO2 for the fabrication of charge storage insulators in the next generation memories. In this study, thin films of zirconia, silica, and zirconium silicate were deposited on Si(100) and glass substrates by R.F. magnetron sputtering from zirconia, silica and zirconium silicate composite ceramic targets instead of metal targets. This research was focused on the evaluations of film growth kinetics, microstructure, mechanical properties, optical properties, and electrical properties. The results showed the films were structurally amorphous, besides 90 ZrO2-10 SiO2 system. The surface morphology of all films were smooth and dense. Their growth rates increased as the silica content and R.F. power increased. The maximum growth rate was nearly 10 nm/min. Regarding to mechanical properties, residual stress was compressive for all films, the hardness of thin films was in the range of 2~12 GPa, and there was a good adhesion to glass substrates with a the maximum critical load of 21.2 N. The refraction index showed a maximum value of 2.17 for pure ZrO2 system. The transmittance with a maximum value of 90 % for pure SiO2 system was influenced by ZrO2 content in targets. In respect of electric properties, the dielectric constant which varied with target composition had a highest of 32. The resistivity was higher than 109 ohm-cm, with a higher value after annealing. The breakdown fields were meassured with values higher than 3 MV/cm.
WANG, CHEN-JUI, e 王貞芮. "The study of copper-silica nanocomposite films". Thesis, 2005. http://ndltd.ncl.edu.tw/handle/54097224380372810920.
Texto completo da fonte國立臺灣科技大學
材料科技研究所
93
This thesis uses the magnetron co-sputter to deposit Cu-SiO2 composite films, and probe electricity in the composite films of different copper content. The first part of experiment studies composition and structure of the as-deposited and annealed Cu-SiO2 films, using XPS. The second part of experiment studies the change of crystallite size in the Cu-SiO2 films, using XRD, TEM, and UV-Visible spectroscopy. The third part of experiment studies electrical properties of the Cu-SiO2 films using Ti/ Cu-SiO2/Ti sandwich structure. Both Cu and Cu2O crystallite appear in the Cu-SiO2 nano-composite films. Crystallite size increases with Cu content, annealing temperatures and time. However, some Cu segregate to surface of the nano-composite films with high concentration Cu. Electrical properties of the Cu-SiO2 films are affected by both the Cu concentration and the annealing conditions. Breakdown voltages of the Cu-SiO2 films decrease but the leakage currents increase while Cu content increases. The Cu-SiO2 films become conductive after the breakdown.