Teses / dissertações sobre o tema "Films de silice"
Crie uma referência precisa em APA, MLA, Chicago, Harvard, e outros estilos
Veja os 50 melhores trabalhos (teses / dissertações) para estudos sobre o assunto "Films de silice".
Ao lado de cada fonte na lista de referências, há um botão "Adicionar à bibliografia". Clique e geraremos automaticamente a citação bibliográfica do trabalho escolhido no estilo de citação de que você precisa: APA, MLA, Harvard, Chicago, Vancouver, etc.
Você também pode baixar o texto completo da publicação científica em formato .pdf e ler o resumo do trabalho online se estiver presente nos metadados.
Veja as teses / dissertações das mais diversas áreas científicas e compile uma bibliografia correta.
Basnig, 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
Wora, Adeola Ganye Vergnat Michel Rinnert Hervé. "Propriétés de luminescence de films d'oxyde de silcium dopés à l'erbium". S. l. : S. n, 2007.
Encontre o texto completo da fonteCABOT, BENJAMIN. "Etudes pour l'elaboration par electrophorese de films anticorrosion a base de silice". Besançon, 1997. http://www.theses.fr/1997BESA2055.
Texto completo da fonteSikolenko, Taisiia. "Films minces de silice mésoporeuse électrogénérée : contrôle de l’épaisseur et applications analytiques". Electronic Thesis or Diss., Université de Lorraine, 2020. http://www.theses.fr/2020LORR0242.
Texto completo da fonteThe combination of rich surface chemistry of silica and ordered perpendicularly-standing hexagonal mesostructure of films generated by EASA makes this material a perfect choice for use as the electrode coatings. In this light, improvement of film design is a constant challenge in order to benefit from porous layer and to increase the efficiency of electrochemical sensors. The first part of project was centred around the optimisation of the film thickness towards the thinnest with preservation of the beneficial hexagonal structure. The mesoporous silica film (MSF) thickness is a parameter that can affect the mass transport through the silica coating to the electrode specifically because of the reactivity of surface silanol groups. Thinning of the MSF can facilitate the diffusion of species, while keeping the presence of the beneficial silica layer can increase the electrochemical response, hence, the sensitivity of analysis. Two approaches were used in order to decrease thickness. The first was a study of the effect of the deposition time during the modification of the electrode (EASA process). The second one was the wet etching of film after its deposition. The thinnest uniform MSFs, which can be generated on indium tin oxide (ITO) surface, require minimum 10 seconds deposition with an applied potential equal to -1.3 V and a 100 mM silane-containing sol. This gave rise to 80 ± 9 nm coating. Post-synthesis etching with the soft fluoride solution of ammonium fluoride, NH4F, allowed to control the decrease of the MSF thickness. By keeping the surfactant inside the silica pores, template agent for the synthesis, the kinetic of the etching reaction was faster, but with a more homogeneous dissolution. It was possible to obtain the thinnest ordered MSF in comparison with an etching procedure conducted on MSF after the extraction of the template. The profilometry determined thickness of well-structured film with vertical pore orientation was respectively of 28 ± 9 nm for the templated silica films and 57 ± 11 nm for films without surfactant inside their pores. In the second part of the study, MSFs were applied to modify ITO electrodes for the development of electrochemiluminescence platform for detection of amine-containing herbicide glyphosate using co-reactant system with Ru(bpy)₃²⁺. Comparison between physical and chemical immobilisation of the organometallic agent was studied. Covalent functionalisation was achievable due to introduction of azide functions on co-condensation step with their further coupling with propargyl-functionalised derivative of Ru(bpy)₃²⁺ complex by Huisgen 1,3-cycloaddition reaction. The effect of the herbicide addition was investigated using electrodes with immobilised by two approaches Ru(bpy)₃²⁺ complex as well as in solution of Ru(bpy)₃²⁺, operating bare ITO electrode and ITO electrode covered with unmodified MSF. The evolution of electrochemical signal was used to conclude on the possibility to detect glyphosate
Motos, 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
JIANG, NAN. "Etude de films minces de silice deposes a basse temperature par pecvd rcer". Paris 11, 1993. http://www.theses.fr/1993PA112340.
Texto completo da fonteCagnol, Florence. "Films minces mesostructures minéraux ou hybrides à base de silice : élaboration, caractérisation, mécanismes". Paris 6, 2004. http://www.theses.fr/2004PA066443.
Texto completo da fonteSibottier, Emilie Walcarius Alain. "Génération électro-assistée de films à base de silice fonctionnalisation, mésostructuration et applications analytiques /". S. l. : S. n, 2007. http://www.scd.uhp-nancy.fr/docnum/SCD_T_2007_0101_SIBOTTIER.pdf.
Texto completo da fonteDourdain, Sandrine. "Caractérisation structurale, poreuse et mécanique de films minces de silice mésoporeuse.Influence de la fonctionnalisation". Phd thesis, Université du Maine, 2006. http://tel.archives-ouvertes.fr/tel-00201895.
Texto completo da fonteLes paramètres pertinents influençant la structuration des films minces ont été appréhendés. En particulier, des études in situ par réflectivité des rayons X et par Diffusion en incidence rasante des rayons X (Grazing Incidence Small Angle X-ray Scattering, GISAXS), ont permis de mettre en évidence le rôle prédominant de l'humidité relative. Des protocoles d'extraction par rinçage à l'éthanol ont été établis pour dégager efficacement les structures mésoporeuses sans les écraser.
Une méthode d'analyse de la porosité des films minces a ensuite été développée. Cette méthode est basée sur l'analyse quantitative des courbes de réflectivité par la méthode matricielle. Complémentée par l'analyse des clichés GISAXS, elle nous a permis de déterminer sur couche mince non seulement la porosité, la taille des pores et des murs mais aussi la surface spécifique et la distorsion des pores.
Les pores de ces films mésoporeux ont une dimension idéale pour y parfaire l'étude de la condensation capillaire de l'eau. Quand l'eau pénètre dans les pores, le contraste de densité électronique décroît fortement. Ainsi, les techniques de diffusion des rayons X (réflectivité et GISAXS) permettent de suivre les isothermes de condensation et de désorption de l'eau dans les pores. La distribution de taille des pores peut alors être obtenue. Les isothermes d'adsorption d'eau ont permis également d'estimer la porosité, mais aussi d'appréhender par le biais de l'équation de Laplace, les propriétés mécaniques des films en accédant à leur module d'Young.
Finalement nous avons conclu cette thèse par l'étude de la fonctionnalisation des films par divers groupements fonctionnels localisés à la surface des mésopores, dans l'optique de modifier leur hydrophilicité ou leur réactivité chimique.
Sibottier, 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 completo da fonteThe 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
Pecheur, Alexandra. "Élaboration et caractérisation de films de SiO2 déposés à basse température (50°C)". Lyon, INSA, 2000. http://www.theses.fr/2000ISAL0054.
Texto completo da fonteThis thesis has aimed to develop a new industrial process for chemical vapor deposition assisted by plasma (PECVD ) of silicon dioxide (Si02 ) at low temperature (50 ° C). This new process should help achieve the encapsulation layer of new magnetic read-write heads (used in computer hard drives) made based GMR (Giant Magneto - Resistance) material and therefore very sensitive to temperature effects. After a brief presentation of the magnetic heads and magneto resistive materials, we show the technological problems related to the encapsulation of magnetic heads. Then we review some background on plasma physics and the various existing methods of depositing Si02 plasma assisted. Then we detail the technological solution chosen and our approach to experimental design for optimizing the operating point of the PECVD technique using a chemical HMDS ( hexamethyldisilazane ) / O2. And SiO2 films deposited on silicon substrates were characterized by an optical and electrical physicochemical perspective. Experimental results show similar thermal properties to those of Si02, particularly as regards the very low surface roughness of the raw films and an excellent “anti- flaw” deposition property observed for non-planar topologies. Epoxy networks / par Sophie Ritzenthaler. - Villeurbanne : Doc'INSA, 2002
Schune, Claire. "Fondus de polymère en mouillage pseudo-partiel sur la silice : morphologie, structure et dynamique des films précurseurs". Electronic Thesis or Diss., Université Paris sciences et lettres, 2020. http://www.theses.fr/2020UPSLS017.
Texto completo da fonteOxidized silicon wafers are high energy surfaces : most liquids spontaneously spread on the entire surface. When a dropletis deposited, a nanometric film called a precursor film first spreads ahead of the droplet. The liquids that we considerin this study are polymer melts (polybutadiene, polyisoprene, polystyrene) in pseudo-partial wetting condition on these surfaces : a sessile droplet coexists with a film. By taking advantage of ellipsometric microscopy, we study the morphologyand dynamics of such films, and quantitatively probe the interactions at stake between the polymer segments and thesurface. Two different parts can be distinguished in the precursor films : the primary film of subnanometric thickness, and the secondary film, which is dense. In the primary film, polymer chains are in a 2D semi-dilute state : they do not cover theentire substrate and do not interact with each other. From the spatio-temporal thickness profiles, we measure the diffusion coefficient of the chains on the surface. We show that they diffuse with a thermally activated Rouse motion, that can be described by the sole friction of the chains on the surface, with an activation energy that reveals the interactions at stake.We measure that the polymer/surface interactions largely dominate the polymer/polymer interactions. We generalize thismodel for polymers with specific terminal groups, and to the case of chains with monomer conformational mobility that depends on the monomer position along the chain. The secondary film connects the primary film to the droplet, and is comprised of chains in a dense state. At long times, its thickness profile is a step of uniform thickness, which is proportionalto the square root of the chain length. Remarkably, this equilibrium thickness does not depend on the polymer chemistrynor on the surface state – temperature, water adsorbed, oxide layer thickness, etc. The evolution toward this equilibriumstate can be modeled by taking into account both the polymer/surface friction and the polymer/polymer friction. In the literature, only few studies deal with precursor films when the liquid is in pseudo-partial wetting condition. In addition tothe robust measurement of the interactions at stake at the scale of the polymer chains, our work highlights the necessityto re-think the theoretical existing framework for precursor films, and opens many perspectives
Besson, Sophie Marie Catherine. "Films organisés de silice mésoporeuse : Synthèse, caractérisation structurale et utilisation pour la croissance de nanoparticules". Palaiseau, Ecole polytechnique, 2001. http://www.theses.fr/2002EPXX0012.
Texto completo da fonteDAVIDOVITS, JEROME V. "Determination des conditions d'obtention de films monomoleculaires organises : application aux silanes auto-assembles sur silice". Paris 6, 1998. http://www.theses.fr/1998PA066081.
Texto completo da fonteDourdain, Sandrine. "Caractérisation structurale, poreuse et mécanique de films minces de silice mésoporeuse : influence de la fonctionnalisation". Le Mans, 2006. http://cyberdoc.univ-lemans.fr/theses/2006/2006LEMA1020.pdf.
Texto completo da fonteThis work dealt with the synthesis and characterization of mesoporous silica thin films. The synthesis uses the surfactant self-assembly route in order to template a silica gel. Hybrid thin films presenting a high degree of organization at the nanometer scale are obtained. Then the surfactant removal leads to materials of organized and tailored porosities and of large surface areas. Different synthesis parameters have been investigated. In situ measurements carried out by X ray Reflectivity (XR) and Grazing Incidence Small Angle X-ray Scattering (GISAXS) have evidenced the major role played by the relative humidity. Some surfactant removal methods by ethanol rinsing have also been tested, with the intent to empty the mesopores without collapsing the mesostructured films. Based on the complete analysis of the reflectivity curves, a new method to determine the porosity of thin films has been developed. In combination with GISAXS experiments the pore and wall sizes, the surface area of the films and their pore distortion were obtained. The mesopores have a perfect size to promote the capillary condensation of water at ambient relative humidity. As the electron density contrast decreases strongly when water infiltrates the mesopores, the XR and GISAXS techniques have permitted to monitor by different ways the adsorption and the desorption of water in the porous network. The pore size distribution and porosity were estimated from the analysis of isotherms. Looking at the direct film structure deformation during the humidity cycles, some mechanical properties have also been investigated yielding the quantitative determination of the Young Modulus. Finally, this thesis was concluded by the study of the mesoporous films functionalisation. Different kinds of chemical functions have been grafted at the surface of mesopore with the aim to modify their hydrophilicity or their chemical reactivity
Dourdain, Sandrine Gibaud Alain. "Caractérisation structurale, poreuse et mécanique de films minces de silice mésoporeuse influence de la fonctionnalisation /". [S.l.] : [s.n.], 2006. http://cyberdoc.univ-lemans.fr/theses/2006/2006LEMA1020.pdf.
Texto completo da fonteGuillemin, 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
Ben, Khemis Sirine. "Couche mince de silice amorphe dopée en alumine comme barrière de diffusion dans les verres fonctionnalisés". Electronic Thesis or Diss., Sorbonne université, 2021. http://www.theses.fr/2021SORUS578.
Texto completo da fonteFunctionalized glasses with thin films are generally subjected to thermal treatments at high temperatures (550-650 °C). During this step, chemical diffusion phenomena can take place from the glass substrate towards the thin layers, which can lead to the degradation of the product’s performance. As such, barrier layers are often incorporated into the thin films stack to limit ion diffusion. Within this framework, the properties of alumina-doped silica thin films, used as a diffusion barrier layer, were investigated. The challenge of this study comes from the nanometric thicknesses and the amorphous nature of the silica films, which asked a special characterization development. The investigation of the atomic structure of the sputtered silica thin films is the first research axis of this thesis. Magnetron sputtering generates densification of the silica layer structure, which is characterized by a decrease in inter-tetrahedral angles and a drastic increase in the proportion of small three-membered rings. Understanding the impact of deposition pressure and the alumina doping into the silica layer network is the second focus of this structural study. In addition to the composition of the glass substrate, the structural properties of the silica layers are the key parameters controlling the alkali diffusion from the glass substrate towards the thin film. The Al2O3 doping of the silica film has been shown to strongly enhance the diffusion of alkali ions from the glass substrate, to ensure the charge compensation of the AlO4- tetrahedra. The increase in deposition pressure affects the kinetics of alkali diffusion by generating a porous, proton-rich, structure
Rosaye, Jean-Yves. "High/low temperature C-V Characterization of defects in ultra thin SiO2 films". Perpignan, 2001. http://www.theses.fr/2001PERP0437.
Texto completo da fonteRohani, Vandad. "Etude de la synthèse chimique de films minces d'oxydes de silicium sur surfaces métalliques assistée par décharge à barrière diélectrique à pression atmosphérique". Paris 11, 2009. http://www.theses.fr/2009PA112013.
Texto completo da fonteIt is estimated that corrosion costs represent about 4% of GNP in developed countries. This high figure highlights the importance of the struggle against this phenomenon. While affecting all materials, corrosion is especially damaging to metals, which suffer from high thermodynamical instability in the atmosphere. A relevant alternative to metals protection is to coat metallic surfaces with a more stable material, e. G. Silicon oxides. Plasma assisted Chemical Vapour Deposition (CVD) techniques have been increasingly spreading among chemical techniques. Particularly adapted to the treatment of thermosensitive products, they allow keeping the substrate’s temperature at low levels (T<250°C). In this document, we consider simple Dielectric Barrier Discharge (DBD) assisted CVD to elaborate silicon oxides thin films on large metallic surfaces (>50 cm2) for metallurgical applications, from a gas mixture which includes HMDSO (hexamethyldisiloxane). Remarkably, this process operates under atmospheric pressure, a condition suited for high speed on-line treatment of large surfaces. The first aim of this study is to show the feasibility of such coating process on steel substrates. In a second part, we examine the quality of synthesized thin films from three carrier gas (He,Ar,N2) to find a possible explanation for the inhomogeneity of coatings obtained by this means
Wora, Adeola Ganye. "Propriétés de luminescence de films d’oxyde de silcium dopés à l’erbium". Thesis, Nancy 1, 2007. http://www.theses.fr/2007NAN10132/document.
Texto completo da fontePhotoluminescence (PL) at 1.54 µm from erbium is studied in two systems containing silicon clusters. The first one consists of size-controlled silicon nanoclusters (Si-nc) obtained by annealing SiO/SiO2 multilayers. A coupling effect between Si-nc and Er3+ ions has been proved. The Si-nc size effect on PL at 1.54 µm has been also studied. The second system consists of SiOx (x _ 2) films. These films which not contain Si-nc show intense PL at 1.54 µm and the maximum is obtained for the SiO1 sample annealed at 700°C. The origin of this PL is correlated to the structure of the films. Time-resolved PL measurements at room-temperature and at helium temperature have been performed to study the luminescence mechanisms at 1.54 µm
De, 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
Maouacine, Koceila. "Matériaux hybrides poreux silice/polymère comme électrolytes pour batterie lithium-ion tout solide". Electronic Thesis or Diss., Aix-Marseille, 2023. http://www.theses.fr/2023AIXM0024.
Texto completo da fonteThe design of lithium-ion batteries using a solid electrolyte is currently one of the most studied ways to overcome safety problem of these devices. In this thesis work, we propose a new approach to develop a porous silica/polymer hybrid electrolyte, containing a higher weight fraction of mesoporous silica than polymer. Two morphologies of silica hybrid materials were studied: as compressed powders (pellets) and as thin films. In the first part of the work, a hybrid silica powder was synthesized and then calcined to liberate the porosity. The mesoporous silica was then functionalized with different polymers of PEG of low molecular weight then by a simple solution impregnation. The hybrid powders were shaped as pellets, presenting inter- and intra-particle porosity. It was shown that the hybrid pellets present promising ionic conductivity properties when the inter- and intraparticle porosities are filled with the PEG-LiTFSI complex for PEG of low molar mass (300-600 g/mol). In the second part, mesoporous silica films were deposited on a glassy carbon electrode using a rotating disc electrode (RDE). After the characterization of these films from a textural properties and a microstructure point of view, they were functionalized by the PEG-LiTFSI complex via an impregnation process and the preliminary study of their ionic conductivity was performed
Karman, Cheryl. "Génération électrochimiquement assistée de films sol-gel nanostructurés orientés : fonctionnalisation par « chimie click », caractérisation et applications". Thesis, Université de Lorraine, 2017. http://www.theses.fr/2017LORR0218/document.
Texto completo da fonteIn this work, we exploited the vertically-aligned mesoporous silica thin films generated by electro-assisted self-assembly (EASA). First of all, we present a study about the amplification of charge transfer of a repulsed anionic redox probes [i.e. Fe(CN)63-/4-] through the negatively charged silica film by using neutrally or positively charged redox probes [Fc(MeOH)2 or Ru(NH3)63+ respectively] through redox mediating processes. Furthermore, the functionalization can be conducted by combining EASA method to obtain azide-functionalized silica film and further letting it react with an ethynyl-bearing reactant (e.g. ethynyl-ferrocene) according Huisgen click chemistry. The resulting ferrocene-functionalized silica films are electroactive, involving an electron hopping mechanism between adjacent ferrocene moieties. The electrochemical oxidation of ferrocene into ferricinium ion generates positive charges that are compensated by the ingress of anions into the film, opening the door to possible indirect amperometric detection of non-electroactive anions by flow injection analysis. Operating in an electrolyte-free flow, each injection of an anion (e.g., NO3-) at an electrode biased at a suitable positive potential (i.e., +0.5 V) gave rise to an amperometric response proportional to the anion concentration. However, to avoid the decrease of the electrochemical signal due to the progressive consumption of ferrocene in multiple successive analyses, it was necessary to regenerate the electrode by reduction of ferricinium moieties, which can be achieved in-situ by square wave amperometry. The feasibility to apply such indirect amperometric detection scheme in suppressed ion chromatography (for detecting anions in mixture) was also demonstrated. The oriented mesoporous film can also be functionalized with ruthenium(II)bipyridyl complex [Ru(bpy)2(bpy’)]2+ using the same method. Optimization of the functionalization level is controlled electrochemically by cyclic voltammetry (CV) and monitored through the UV-vis spectra. Further study is conducted upon the charge transfer (electron hopping along the adjacent sites) and the mass transfer of the compensating counter anion through the mesochannels by varying the CV potential scan rate. The emission of the [Ru(bpy)2(bpy’)]2+-functionalized film and its quenching in the presence of oxygen are evidenced in both aqueous and organic solvent, giving opportunities to apply the film for different application, such as electrochemiluminescence sensor and oxygen detection. Lastly, the vertically-aligned mesoporous silica film is used as a hard template to grow polyanilinine nanofilaments. The growth of ordered polyaniline nanofilaments is controlled by potentiostatic polymerization. In such small pore template (2 nm in diameter), quasi-single PANI chains are likely to be produced. From chronoamperometric experiments and using films of various thicknesses (100−200 nm) it is possible to evidence the electropolymerization transients, wherein each stage of polymerization (induction period, growth, and overgrowth of polyaniline on mesoporous silica films) is clearly identified. The advantageous effect of mesostructured silica thin films as hard templates for the generation of isolated polyaniline nanofilaments is demonstrated from enhancement of the reversibility between the conductive and the nonconductive states of polyaniline and the higher electroactive surface areas displayed for all mesoporous silica/PANI composites. The possibility to control and tailor the growth of conducting polymer nanofilaments offers numerous opportunities for applications in various fields including energy, sensors and biosensors, photovoltaics, nanophotonics, or nanoelectronics
Yonger, Marc. "Dynamique du mouillage pseudo-partiel de la silice par des fondus de polymère". Thesis, Paris 6, 2016. http://www.theses.fr/2016PA066274/document.
Texto completo da fontePrecipitated silica, which is porous at the 10 nm scale, has various industrial uses where it is mixed with polymer melts, with characteristic molecular sizes in the nanometer range. Having a high surface energy, silica tends to be covered by most liquids. As a consequence, when a liquid droplet is deposited on silica surfaces, a thin “precursor” film spreads in front of the droplet, with a thickness of a few nanometers. By combining macroscopic observations and ellipsometry imaging, we found that polybutadiene and polystyrene melts on silica are in pseudo-partial wetting conditions, for which a droplet coexists with a precursor film at equilibrium, due to attractive long range forces at the film length scale. The precursor film is composed of quasi-isolated molecules diffusing in two dimensions with a diffusion coefficient equal to the bulk self-diffusion coefficient. This provides valuable information on the polymer/silica interactions. Furthermore, we occasionally observe the growth of an instability, as a “secondary” film which is thicker than the precursor film. In contrast, polydimethylsiloxane melts are in total wetting conditions on silica: at equilibrium, a polymer film covers the silica surface and no droplets coexist with the film, due to repulsive long range forces. Our observations of the imbibition of porous silica by polymer melts were related to these results. Eventually, for low molar mass polymers, we find that the precursor film has no significant impacts on porous silica pellets imbibition
Faye, Ndeye rokhaya. "Etude par microscopie à force atomique et par microscopie de fluorescence de l’interaction de nanoparticules de silice avec des films lipidiques plans". Thesis, Bordeaux, 2014. http://www.theses.fr/2014BORD0483/document.
Texto completo da fonteThe subject of this thesis fits into the large field of the toxicity of nanoparticles (NPs). Thanks to their physico-chemical properties, NPs are able to enter cells through the plasma membrane. Understanding the NPs-membrane interaction is thus very important. Membranes being complex structures, we chose to study this interaction using planar lipid films (monolayers and bilayers) as simplified membrane models, either deposited on nanostructured surfaces prepared by the prior deposition of silica NPs or transferred from monolayers spread on a subphase containing NPs (4-100 nm in diameter). Two complementary methods were used, atomic force microscopy (AFM) and fluorescence microscopy.After a first part devoted to the optimization of the experimental procedure (choice of lipids, design of nanostructured surfaces and films), AFM first revealed the oxidation of transferred monolayers made of unsaturated lipids, leading to the formation of domains raised above the intact lipid phase. In the case of films made of lipids characterized by a liquid expanded/liquid condensed phase transition, the presence of NPs (usually organized in aggregates) seems to favor the transition to the condensed phase, NPs being either embedded in condensed domains or at their edges.The final phase of this work was devoted to the study of NPs / bilayer interaction by AFM in liquid medium. The study shows different tribological behavior of NPs aggregates, suggesting two possible organizations of the lipid bilayer, covering the NPs or forming holes around them
Santawitee, Onuma. "Study of piezoelectric devices based on free-standing printed thick-films : application to VOCs detection using micro-cantilevers with mesoporous silicasensitive coating". Thesis, Bordeaux, 2020. http://www.theses.fr/2020BORD0108.
Texto completo da fonteIn recent years, screen-printing process associated with sacrificial layer technique have been developed to prepare piezoelectric MEMS (MicroelectroMechanical Systems) based on lead zirconate titanate (PZT PbZrTiO3) thick films. However, material choices and process conditions (such as pastes compositions, printing conditions and thermal treatment) could affect microstructure and consequently electromechanical properties of printed thick films transducers. With PZT thick films deposited on a composite sacrificial layer based on epoxy and SrCO3, a residual porosity within PZT films is observed. Thus, the obtained PZT films have lower piezoelectric properties compared to a bulk commercial PZT. This work points out improvements of the properties of the printed piezoelectric films by appropriate PZT paste preparation and differences in choices of electrode and sacrificial layer materials. With deposition on a polyester sacrificial layer and using PZT paste containing nano-PZT particles and 3 wt% LBCU sintering aid (Li2CO3, Bi2O3, and CuO), free-standing PZT micro-disks showed improved densification after firing at 900°C (≈7.4 g/cm3). Furthermore, Ag/Pd electrodes led to better PZT/electrode interface compared to Au electrodes. As a result, higher values of effective electromechanical coupling coefficient (≈45%) and relative permittivity (≈1200) were obtained. In the second part of this work, the optimized paste was used for processing of a micro-cantilever dedicated to Volatile Organic Compounds (VOCs) detection. The principle of this sensor is based on the measurement of resonant frequency shifts of the vibrating cantilever when exposed to target species. When the cantilever coated with a sensitive coating presented high sorption capacity, these shifts could be negative due to a mass increase. For this application, various geometries of PZT cantilevers were fabricated (from 310.1 mm3 to 620.1 mm3). Then, the cantilever in size of 320.1 mm3 was chosen for sensing application because it gave acceptable values of mass sensitivity (≈27 Hz/µg) and had enough surface area for receptor depositing. Meso-cellular foam silica (MCF-Si) is one type of mesoporous materials which is attractive to be used as receptor (sensitive layer) due to its large pore size and pore volume. Here, it was synthesized by sol-gel method before functionalization by hexamethyldisilazane (HMDS) to be more hydrophobic. HMDS functionalized MCF-si’s surface area, pore size and pore volume were ≈484 m2/g, 6.59 nm and 0.906 cc/g, respectively. Finally, this porous material (≈50 µg) was dropped onto the free-end of the PZT cantilever before detection of VOCs at room temperature. Low responses under vapors of water, ethanol and benzene were noticed whereas the sensor showed a very good sensitivity to toluene vapor. Also, frequency shifts could be positive or negative because of a competition between mass and stiffness effects. These effects depended on cantilever surface (uncoated or coated with sensitive layer) and on the target vapor nature and concentration. With the acceptable values of sensitivity to toluene (≈ 0.24 Hz/ppmV) and the limit of detection (≈25 ppm), the sensor would be benefit to environmental monitoring field
Ullah, Wahid. "Synthèse électrochimique de nanoréseaux métalliques et polymériques au travers de films minces de silice mésoporeuse à canaux verticalement orientés". Electronic Thesis or Diss., Université de Lorraine, 2021. http://www.theses.fr/2021LORR0093.
Texto completo da fonteIn this project we exploited surface modification of electrodes with vertically oriented mesoporous silica thin films, generated by electrochemically assisted self-assembly method. The silica scaffold offers narrow pores diameter around 2-3 nm and 50-150 nm film thickness, a competitive hard template material for the preparation of low dimensional metallic and organic nanopatterns on conducting surfaces. We combined the wealth of mesoporous silica thin film with electrochemistry to obtain surface nanopatterning of the underlying support. Well-adhered and mechanically stable mesoporous silica film is formed on electrodes bearing hydroxyl moieties on their surface, for example indium tin oxide (ITO). However, the adhesion and mechanical stability of mesoporous silica thin film is poor on noble metals such as gold (Au). To ensure uniform surface coverage and good adhesion of the silica film to the Au surface, it was necessary to use a (3-mercaptopropyl) trimethoxysilane (MPTMS) reagent to act as a “molecular glue” thanks to its thiol functionality, which is able to bind to the gold substrate and to its alkoxysilane moieties enabling condensation with the silica material. The MPTMS layer had, however, a significant effect on film permeability to redox probes, depending on the MPTMS treatment time. MPTMS adsorption should be long enough to ensure proper adhesion of the film but not too long to avoid surface blocking or film defects. In addition, Cu underpotential deposition (UPD) experiments revealed that the silica membrane significantly affected the UPD process, suggesting some barrier effect of the porous membrane, but the interface Au/MPTMS/silica is not sharp and allowed metal UPD between the gold substrate and the silica thin film. In the second part of the thesis, mesoporous silica thin films, with two distinct pore diameters (2.0 and 2.9 nm), covered ITO electrodes were used as hard template for the control electrochemical growth of polyaniline (PANI) nanowire arrays. To ensure proper adhesion of PANI to the underlying ITO surface, aniline moieties are first covalently attached to the bottom of mesochannels via electrografting of aminophenyl diazonium cations, serving in a second step as precursors for PANI growth by electropolymerization of aniline through the silica mesochannels. PANI wires remain attached to ITO after removal of the silica membrane, confirming the importance of initial electrografting. Both PANI inside silica template and the free PANI nanowire arrays were electroactive. Spectroelectrochemical study revealed fast electrochromic behavior and cycling stability of PANI nanowire arrays. In last part of the project, some preliminary attempts were made for the electrochemical co-deposition of bimetallic Cobalt/Platinum (CoPt) nanowire arrays onto ITO electrode covered with mesoporous silica films. The presence of Co and Pt in the deposits was confirmed from surface analysis by spectroscopic methods and electrochemical characterization
Morel, Dominique. "Etude de l'état physique de films monomoléculaires de chaînes alkyles linéaires à la surface des silices, et de leurs propriétés chromatographiques". Lyon 1, 1985. http://www.theses.fr/1985LYO19020.
Texto completo da fonteMatheron, Muriel. "Films mésoporeux hybrides organiques-inorganiques : synthèse, organisation des pores et application en optique ophtalmique". Phd thesis, Ecole Polytechnique X, 2005. http://pastel.archives-ouvertes.fr/pastel-00003326.
Texto completo da fonteGiordano, Gianmarco. "Electro-assisted deposition of sol-gel thin films: study of the process and its applications". Doctoral thesis, Università degli studi di Padova, 2018. http://hdl.handle.net/11577/3426802.
Texto completo da fonteLo scopo del lavoro di tesi è lo studio del processo di deposizione di film sottili con il metodo sol-gel per via elettrochimica, cercando di individuare i limiti della tecnica e, dall'altro lato, suggerendone la versalità. Dopo un'attenta analisi della letteratura, e stato effettuato un primo studio sistematico delle variabili principali che governano il processo, implementando il metodo con la tecnica del potenziale pulsato. Per la prima volta in letteratura, le curve cronoamperometriche sono state analizzate al variare della concentrazione di precursore e del potenziale applicato, trovando una forte analogia con la crescita 3D di metalli depositati elettrochimicamente. Le curve sono state simulate usando le equazioni di nucleazione 3D progressiva con crescita a controllo diffusivo. E' stato dimostrato che con l'elettrodeposizione assistita è possibile costruire strutture multilayer con materiali ibridi organici-inorganici a base di silice. Inoltre, questa tecnica può essere usata per aumentare lo spessore di film sottili mesoporosi con nano-canali orientati verticalmente rispetto al substrato e ben ordinati con struttura esagonale. Infine, film sottili di silice e titania sono stati intercalati al fine di aumentare la riessione del substrato e i rispettivi indici di rifrazione sono stati misurati e confrontati su diversi substrati. Il processo NIP (nanoparticles imprinted polymers) è stato implementato usando una matrice di silice anziché polimerica. Un monolayer di PDDA è stato depositato su un substrato di ITO e, per mezzo dell'attrazione elettrostatica, delle nanoparticelle di oro stabilizate con citrato sono state depositate al di sopra di esso. Quindi, un sottile strato di silice a spessore controllato è stato usato per incorporare parzialmente le nanoparticelle. Dopo l'ossidazione dell'oro per via elettrochimica, è stato monitorato il riaccalappiamento delle nanoparticelle da parte della matrice impressa.
Yin, Quanyi. "Thiol-para-fluoro modified PPFS as building blocks for the design of silica-based nanocomposite and layer by layer self-assembled thin films". Thesis, Lyon, 2018. http://www.theses.fr/2018LYSEI025/document.
Texto completo da fonteThis work describes the preparation of two kinds of thin polymer films : i) self-cleaning silica-based (nano)composites films and ii) LbL self-assembling films, both including poly(2,3,4,5,6-pentaflurostyrene) (PPFS) derivatives, as building blocks. The cornerstone of the approach is to exploit the thiol-para fluoro substitution reaction to PPFS chains in order to generate derivatives with tailored properties. In this frame, PPFS chains were anchored onto the surface of vinyl-functionalized fumed silica nanoparticles by nitroxide-mediated polymerization (NMP) in presence of PS-DEPN as macro-initiator via a “grafting through” strategy. The kinetics of NMP of PFS were investigated in presence and without silica in various solvents and well-characterized hybrid silica particles containing different polymer grafting weight were declined. Then, perfluorodecanethiol (PFDT) was employed to modify PPFS, considered as the host polymer matrix, and to functionalize PPFS chains tethered to silica particles. A large panel of (nano)composite films from the different possible host matrix/silica particles combinations was prepared. The wettability and the surface morphology of each film were discussed, as a function of the host structure (PPFS or PPFS-PFDT with different DS) and silica (modified with PPFS or PPFS-PFDT), as well as the silica content. It results that superhydrophobic features can be reached. Subsequently, PPFS was modified by using carboxylic acid mercapto modifier via the thiol-para fluoro coupling. Various carboxylated PPFS derivatives differing in the degree of substitution (DS) were prepared and their ability to develop H-bonds in solution with a model strong H-bond acceptor partner (poly(4-vinyl pyridine) (P4VP)) was investigated. Dependently on the nature of the solvent, a miscible blend or interpolymer complexes (IPC) were achieved. IPC-containing solutions were used to successfully fabricate spin-assisted films. Furthermore, H-bonds mediated LbL self-assembly multilayer films involving carboxylated PPFS and P4VP were prepared and it was evidenced that the nature of the deposition solvent as well as the extent of the modification (quantified by the DS), impact the growth mechanism, the thickness and the surface features, in terms of topology and wettability
PLAIS, FRANCOIS. "Etude du depot de films minces de silice par plasma multipolaire microonde. Application a l'etude de structures sio#2-inp". Paris 6, 1991. http://www.theses.fr/1991PA066283.
Texto completo da fonteDubray, Jean-Jacques. "Stimulation superficielle de la réaction de nitruration de films minces de silice par voies : thermique, sous faisceau d'électrons, et plasma". Aix-Marseille 2, 1989. http://www.theses.fr/1989AIX22059.
Texto completo da fonteChemin, Nicolas. "Propriétés mécaniques de films hybrides nanocomposites : étude du rôle des interfaces sur le système PHEMA-Silice-Nanoparticules d'oxyde de fer". Paris 6, 2007. http://www.theses.fr/2007PA066584.
Texto completo da fonteLatreche, Mohamed. "Contribution à l'étude des procédés de croissance de films minces obtenus par plasma RCER à partir de monomères organosiliciés". Toulouse 3, 1993. http://www.theses.fr/1993TOU30037.
Texto completo da fonteLegrandjacques, Pozzolo Sandrine. "Influence des propriétés de la matrice sur le comportement à la rayure de réseaux époxy-amine chargés par des nanoparticules de silice&". Paris 6, 2005. http://www.theses.fr/2005PA066148.
Texto completo da fonteDesfours, Caroline. "Elaboration et caractérisation de films ultraporeux de silice par voie sol-gel : application à des systèmes de biodétection et de microchauffage". Phd thesis, Montpellier 2, 2009. http://www.theses.fr/2009MON20252.
Texto completo da fonteIn this work, ultraporous silica layers with very low refractive indices (1,1-1,2) and thicknesses about one micrometer are prepared and integrated to two systems of sensors for different applications. The synthesis of the initial solution is optimized from the sol-gel standard two steps. Due to its high porosity, the deposited layer has two remarkable properties : low refractive index and low thermal conductivity. Our study is based on the establishment of two systems : a reverse symmetry waveguide and an heating microsystem. The achievement principle of the reverse symmetry waveguide is based on a stack of three layers with a central layer with higher refractive index than the surrounding media. The particularity of this guide is due to the index of the lower middle (ultraporous layer) which is lower than the upper middle. In an application to build a multilayer film type polyelectrolyte / protein and to test the depth of evanescent field sensing, poly-L-lysin and caseins multilayers are adsorbed on the waveguide surface. From the variation of the effective refractive index, one can determine the mass of biomolecules deposited and we show the sensitivity of this system. In the second application of the ultraporous layer, the technology of heating microsystem is based on the integration of this layer between metal resistance and its substrate. It is highlighting that this addition allows a better concentration of energy supplied
Desfours, Caroline. "Elaboration et caractérisation de films ultraporeux de silice par voie sol-gel _ Application à des systèmes de biodétection et de microchauffage". Phd thesis, Université Montpellier II - Sciences et Techniques du Languedoc, 2009. http://tel.archives-ouvertes.fr/tel-00690714.
Texto completo da fonteDaniel, Alain. "Revêtements minces Zn-Si-O et Ti-Si-O : élaboration au moyen d'un procédé plasma hybride pulvérisation cathodique-PECVD et caractérisation". Thesis, Vandoeuvre-les-Nancy, INPL, 2006. http://www.theses.fr/2006INPL087N/document.
Texto completo da fonteThe present work deals with the synthesis of Zn-Si-O and Ti-Si-O composite thin films by a hybrid process. The coatings are prepared by combining PECVD (Plasma Enhanced Chemical Vapour Deposition) of silicon oxide from hexamethyldisiloxane (HMDSO-Si2C6H180) and reactive sputtering of a zinc or a titanium target. Any composition of the deposited layer can be obtained from zinc oxide or titanium oxide to silicon oxide, by controlling the HMDSO flow rate in the reactor. The morphologies evolve from columnar to dense by adding silicon in the coating. Moreover, a competitive deposition process takes place between PECVD and sputtering. The critical flow rates above which the PECVD silicon oxide deposition takes place on the substrate and on the target can be described from measurements of the thin film deposition rates as a function of the HMDSO flow rate. The coating caracterisations show that they are, near the coating-substrate interface, made of a mixture of non-stoechiometric oxides whose composition is different from a ZnO+SiO2 or a TiO2+SiO2 mixing. Titanium and silicon are in excess near the coating-substrate interface, respectively in the Ti-Si-O and Zn-Si-O thin films. Then the atomic concentrations of titanium and silicon progressively decrease when reaching the surface of the thin film. These behaviours are correlated with an increase of the temperature during the first phase of deposition that increases the PECVD deposition kinetics and determines the contamination state of the target
Yonger, Marc. "Dynamique du mouillage pseudo-partiel de la silice par des fondus de polymère". Electronic Thesis or Diss., Paris 6, 2016. http://www.theses.fr/2016PA066274.
Texto completo da fontePrecipitated silica, which is porous at the 10 nm scale, has various industrial uses where it is mixed with polymer melts, with characteristic molecular sizes in the nanometer range. Having a high surface energy, silica tends to be covered by most liquids. As a consequence, when a liquid droplet is deposited on silica surfaces, a thin “precursor” film spreads in front of the droplet, with a thickness of a few nanometers. By combining macroscopic observations and ellipsometry imaging, we found that polybutadiene and polystyrene melts on silica are in pseudo-partial wetting conditions, for which a droplet coexists with a precursor film at equilibrium, due to attractive long range forces at the film length scale. The precursor film is composed of quasi-isolated molecules diffusing in two dimensions with a diffusion coefficient equal to the bulk self-diffusion coefficient. This provides valuable information on the polymer/silica interactions. Furthermore, we occasionally observe the growth of an instability, as a “secondary” film which is thicker than the precursor film. In contrast, polydimethylsiloxane melts are in total wetting conditions on silica: at equilibrium, a polymer film covers the silica surface and no droplets coexist with the film, due to repulsive long range forces. Our observations of the imbibition of porous silica by polymer melts were related to these results. Eventually, for low molar mass polymers, we find that the precursor film has no significant impacts on porous silica pellets imbibition
Petit, Christian. "Contribution à l'étude de la dégradation de films minces et ultra-minces de SiO2 de structures MOS soumises à des contraintes électriques et à la caractérisation par spectroscopie tunnel inélastique de jonction Al-SiO2-Si". Reims, 2004. http://theses.univ-reims.fr/exl-doc/GED00000021.pdf.
Texto completo da fonteMore the integrated circuit density increases , more the transistor size (channel length and width, gate oxide thickness) decreases. Below 3nm oxide thicknesses, the current in depletion regime becomes measurable and increases after electrical stresses. The increase of this current, called LVSILC (Low Voltage Stress Induced Leakage Current), does not affect the device and circuit functionality because it is observed in depletion or weak inversion regimes and not at usual operating voltages, but it can be used to monitor the oxide degradation and to predict the charge to breakdown. We have realized an experimental data base on the LVSILC evolution, with stress voltages and temperatures, for various oxide thicknesses and in P and N-MOSFETs. This allow us to predict the device lifetime, and to show that the degradation mechanism is more probably linked to hydrogen release from the interface than to anode hole injection. We have also tried to realized a physical characterisation by inelastic electron tunnel spectroscopy (IETS). This work allow us to identify both electrode (substrate and gate) and gate oxide phonon modes. We have also identified the vibratory modes of some defects or impurities induced in the gate oxide during the fabrication process
Maechler, Louison. "Dépôts de films organosiliciés réalisés par décharge à barrière diélectrique homogène à la pression atmosphérique : application aux films multicouches". Toulouse 3, 2010. http://thesesups.ups-tlse.fr/1070/.
Texto completo da fonteThe aim of this work is to better understand deposition processes of thin films using an atmospheric pressure cold plasma, through the synthesis of organic and inorganic materials. Two discharges are used: the Atmospheric Pressure Townsend Discharge (APTD) in nitrogen and the Atmospheric Pressure Glow Discharge (APTD) in helium. In both cases, the precursor used is hexamethyldisiloxane (HMDSO) and the oxidizing gas is nitrous oxide (N2O). The approach consists in firstly determining the chemical and structural properties of films obtained with or without oxidant gas. After this step, a discussion is proposed on the gas-phase reaction mechanisms that may explain the obtained deposits. Finally, this work highlights some possible applications of these deposits obtained at atmospheric pressure through the realization of gas barrier multilayers and of rigid multilayers with antifog properties
Bréard, David. "Croissance de films minces de silice enrichies en nano-grains de silicium et dopées aux ions Nd3+ : caractérisation et optimisation des propriétés optiques". Phd thesis, Université de Caen, 2007. http://tel.archives-ouvertes.fr/tel-00559984.
Texto completo da fontePetit, Christian Meinertzhagen Anne Salace Guy. "Contribution à l'étude de la dégradation de films minces et ultra-minces de SiO2 de structures MOS soumises à des contraintes électriques et à la caractérisation par spectroscopie tunnel inélastique de jonction Al-SiO2-Si thèse pour le doctorat en sciences spécialité Electronique /". Reims : S.C.D. de l'Université, 2005. http://scdurca.univ-reims.fr/exl-doc/GED00000021.pdf.
Texto completo da fonteRegnier, Christophe. "Dépot chimique en phase vapeur d'oxydes (SiO2, Al2O3) sur des substrats métalliques dans une post-décharge micro-onde : caractérisation des films et modélisation du plasma d'oxygène". Limoges, 1995. http://www.theses.fr/1995LIMO0042.
Texto completo da fonteWang, Jianren. "Nanostructured Redox-Active Mesoporous Silica Films Based on An Electron-Hopping Mechanism : Charge Transfer Behaviors And Energy Storage Potentials". Electronic Thesis or Diss., Université de Lorraine, 2020. http://www.theses.fr/2020LORR0216.
Texto completo da fonteA new type of silica-based energy storage materials operating with electron-hopping mechanism has been prepared by combining electrochemically-induced self-assembly method (EASA) and a copper-catalyzed azide-alkyne click (CuAAC) reaction. The redox active centers (ferrocene or cobaltocenium molecules) distributed on the surface of the silica film can directly commute electrons via the electron-hopping process. The results demonstrate this charge transfer mechanism is able to deliver a fast electron transfer rate even on the insulating silica substrate, resulting in a superior rate performance in comparison to the traditional faradic materials. The high density of redox molecules and the smooth counter ions diffusion pathway have been identified playing a pivotal role to ensure the fast electron-hopping process. Besides, the large-scale assembly of the electron-hopping system has been achieved by further generating the ferrocene functionalized silica film on a free-standing graphene foam electrode, exhibiting a 100-times higher capacity density, in comparison to that generating on ITO electrode, while maintaining the high rate performance. Finally, an attempt has been tried to assemble the graphene-supported ferrocene-functionalized silica into a flexible planar device, and the preliminary results has proved the feasibility of our proposed idea. Overall, in this thesis, the systematical study for the potential of the electron-hopping process in the energy storage field, which may pave a new way for the construction of energy storage materials
Ramamonjinirina, Evelyne. "Formation de films mixtes au sein de silices greffées poreuses par insertion de molécules alkylées à groupements fonctionnels variés : étude de leurs propriétés chromatographiques". Lyon 1, 1986. http://www.theses.fr/1986LYO10081.
Texto completo da fonteLaugel, Nicolas. "Mécanismes de construction de films multicouches de polyélectrolytes : Relations entre les régimes linéaire et exponentiel et la perméabilité aux ions multivalents". Université Louis Pasteur (Strasbourg) (1971-2008), 2007. https://publication-theses.unistra.fr/public/theses_doctorat/2007/LAUGEL_Nicolas_2007.pdf.
Texto completo da fontePolyelectrolyte multilayer films are organic coatings with thicknesses ranging from nanometers to micrometers. The thickness of these films can increase either linearly or exponentially with the number of deposition steps. The aim of this thesis was to better the comprehension of the internal structure of these films, as well as the interactions that lead to their formation. The first part of this work allowed to establish a relation between the growth regime of a film built with a given polyelectrolyte pair and the complexation enthalpy of the same pair in solution. The second part was a study of the interactions between ferrocyanide and an exponential growing polyelectyrolyte multilayer film by cyclic voltammetry. The last part, taking advantage of the results yielded by the other parts, consisted in the build-up and characterization of organic-inorganic composite films, using a reactive deposition method
Bahlawane, Naoufal. "Dépôt par PACVD et caractérisation de films minces de SiOxCy : évaluation de la perméation aux gaz et de l'adhésion". Lyon 1, 1998. http://www.theses.fr/1998LYO10140.
Texto completo da fonte