A study was carried out on formulations of organic-inorganic hybrids and their subsequent use as matrices for unidirectional carbon fibre-reinforced composites. The hybrids consist of low molecular weight polyimide precursors and silica which is generated in-situ via the sol-gel route. A special feature of these systems is the use of organofunctional trialkoxysilanes as coupling agents for the two phases and for controlling the resultant morphology. Enhancements are obtained in physicochemical, thermal and mechanical properties of hybrids through morphological modifications achieved in the parent polyimide and silicate materials. Small variations to the composition of the precursors display a substantial effect both on the kinetics of the associated reactions and the final properties of hybrids, often as a result of a change in miscibility of the organic and the inorganic components of the system. The processability of the matrix was evaluated with respect to the fabrication of composites, which in this case is strongly influenced by the gelation behaviour of both the organic pre-polymer and also the inorganic sol-gel component. The kinetics of gelation reactions were examined by dynamic viscometry and by practical tests based on visual observation of the cessation of flow. Differential scanning calorimetry, infrared spectroscopy, thermogravimetric analysis and electron microscopy formed part of the evaluation of the matrix materials. Composites were produced by application of the matrix solution from a variety of formulations on pre-tensioned fibres, followed by vacuum drying and curing under pressure at high temperatures. The properties of these composites were determined by such methods as dynamic mechanical thermal analysis, flexural testing and thermomechanical analysis. From the results obtained in this study, it is concluded that the inclusion of silicate phase in a polyimide matrix in the form of fine co-continuous networks improves the thermal and mechanical properties of the base material, although these are dependent on the overall silicate content and the amount of the coupling agent. High loadings of the coupling agent can cause degradation by chain scission and a reduction of the crosslinking density of the organic pre-polymer.

No description available.

Les nanomatériaux et nanotechnologies sont devenus un élément incontournable dans l'électronique de faible puissance, la production énergétique / gestion et les réseaux sans fil, offrant la possibilité de construire une vision pour les capteurs autonomes. Cette thèse s’intéresse au concept de systèmes basse température utilisant des structures de matériaux hybrides organique/inorganique pour la réalisation de dispositifs électroniques faible coût, dont les transistors à effet de champ (FET) et les nanogénérateurs piézoélectriques (nommés PENGs) et ce, sur divers substrats en particulier plastiques. Pour atteindre ces objectifs, ce travail décrit d'abord la croissance contrôlée de nanostructures monocristallines de ZnO en utilisant des approches vapeur-liquide-solide (VLS) et hydrothermales à haute et basse température respectivement. Pour les dispositifs FET, les nanostructures ZnO obtenues par VLS sont utilisées en raison de leur haute qualité structurale et optique. Les sections suivantes présentent des différentes études menées pour optimiser les prototypes FET, comprenant (i) les contacts métal-semiconducteur, (ii) la qualité de l'interface semi-conducteur/isolant et (iii) l'épaisseur de diélectrique organique. La dernière section examine la possibilité de fabriquer des systèmes hybrides organiques/inorganiques pour PENGs utilisant l'approche hydrothermale. Certaines des questions clés, ce qui limitent les performances PENG sont abordés : (i) l'effet de porteurs libres et (ii) l'encapsulation polymère. Ce travail démontre le fort potentiel des ZnO nanostructures pour l'avenir de l'électronique. / Nanomaterials and nanotechnology has become a crucial feature in low-power electronics, energy generation/management and wireless networks, providing the opportunity to build a vision for autonomous sensors. The present thesis delivers the concept of low-temperature processable organic / inorganic hybrid systems for the realization of inexpensive electronic devices including field-effect transistors (FETs) and piezoelectric nanogenerators (PENGs) on various substrates including plastics. To achieve these objectives, this work first describes the controlled growth of single-crystalline ZnO nanostructures using high-temperature vapor-liquid-solid (VLS) and low-temperature hydrothermal approaches. For the FET devices, VLS grown ZnO nanostructures are used, owing to their high structural and optical quality. Later sections present different studies conducted to optimize the FET prototypes, includes: (i) metal-semiconductor contacts, (ii) semiconductor/insulator interface quality and (iii) organic dielectric thickness. The last section investigates the possibility to fabricate organic / inorganic hybrid systems for PENGs using hydrothermal approach. Some of the key issues, restricting the PENG performances are addressed: (i) screening effect from free charge carriers and (ii) polymer encapsulation. This work demonstrates the high potential of ZnO nanostructure for the future of electronics.

This dissertation addresses two topics associated with the assembly of surfactants at the solid-liquid interface for adsorption and materials synthesis. The first is the adsorption of an anionic fluorinated surfactant, tetraethylammonium perfluorooctylsulfonate (TEA-FOS), at the solid/liquid interface. Attenuated total reflection Fourier transform infrared spectroscopy is used to study the adsorption kinetics and average orientation of surfactants at the hydroxylated germanium surface. Atomic force microscopy provides complementary images of the adsorbed layer structure on mica. The adsorption follows unusual three-stage kinetics in which the rate of adsorption starts fast, slows as the surface becomes crowded, and then (surprisingly) accelerates due to nucleation of a heterogeneous multilayer structure. These fast-slow-fast three stage adsorption kinetics are observed for a wide range of concentrations at pH 6, and the rates of the three stages are modulated by pH and salt by tuning electrostatic interactions among surfactants, counterions, and the surface. The results suggest that tetraethylammonium mediates interactions between surfactants and with negatively charged surfaces. The dichroism measurements and AFM are consistent with a mechanism in which TEA-FOS first forms an incomplete layer with chains oriented randomly or somewhat parallel to the surface, followed by formation of flattened multilayer clusters with the chains oriented somewhat normal to the substrate. The second topic is the sol-gel synthesis of mesoporous silica materials using dual surfactant templates. Studies of templating with mixed cetyltrimethylammonium bromide and octyl-beta-D-glucopyranoside surfactants shows that the ternary phase diagram of surfactants in water can be used to predict mesoporous materials structure, and that vapor-phase ammonia treatments can either stabilize the structure or induce swelling by the Maillard reaction. Studies of sol-gel reaction-induced precipitation with demixed hydrocarbon and fluorocarbon cationic surfactant micelles show a wide variety of pore structures. A number of synthesis parameters are adjusted to tune the pore structure, for instance to adjust the size and populations of bimodal mesopores. Selective swelling of the two surfactants by liphophilic and fluorophilic solvents is observed. Finally, proteinaccessible hollow spherical silica particles with mesoporous shells are reported. The methods for engineering mesoporous materials reported here have potential applications in adsorption, controlled drug delivery and for catalysis.

Les propriétés fonctionnelles spécifiques des matériaux hybrides organique-inorganique dépendent de leur structure à l’échelle microscopique ainsi que de la nature de l’interface entre leurs composantes organique et inorganique. L’une des voies principales pour synthétiser ces matériaux, consiste à incorporer des blocs inorganiques à l’intérieur d’un polymère. En pratique les applications des matériaux hybrides sont souvent limitées par leur comportement mécanique. En effet, l’augmentation de la concentration de la composante inorganique, à priori souhaitable pour améliorer les propriétés fonctionnelles du matériau, entraine généralement une dégradation des propriétés mécaniques en limitant l’étendue de la polymérisation de la phase organique. La fabrication de matériaux hybrides offrant une combinaison optimale des propriétés mécaniques et fonctionnelles est un problème important auquel nous apportons quelques éléments de réponses dans cette thèse. Pour cela nous démontrons et étudions une nouvelle approche pour la synthèse de matériaux hybrides photosensibles pHEMA-TiO₂ (pHEMA=poly-(2-hydroxyéthyl)méthacrylate) dans lesquels des nanoparticules inorganiques sont dispersées dans un polymère. Le procédé que nous proposons est basé sur l’utilisation de hautes pressions (HP)pour provoquer la polymérisation de la phase organique en l’absence de tout initiateur chimique. Nous avons d’abord observé la polymérisation spontanée du HEMA sous pression statique. La réaction se produit dans un domaine de pression limitée 0.1-1.6 GPa, en dessous du seuil de transition vitreuse, et est très peu efficace puisque le taux de conversion des monomères n’excède pas 28 % après 41 jours. La réaction peut cependant être considérablement accélérée lorsque l’échantillon sous pression est irradié dans le domaine UV. Nous avons montré que cela résultait de l’excitation à un photon de l’état triplet HEMA (T1) rendue possible par la modification de la structure électronique du HEMA sous HP. Cette méthode ne pouvant être utilisée pour la synthèse de matériaux photosensibles dans le domaine UV, nous avons développé une approche originale basée un cycle de compression-décompression. Lors de la phase de compression (> 6.5 GPa) des biradicaux (HEMA)₂ sont formés à partir de monomères excités HEMA (T1). À cette pression les contraintes stériques empêchent la formation de plus longs oligomères. La polymérisation ne se produit que dans une seconde étape lorsque l’échantillon, décompressé entre 0.1 et 2 GPa, est en phase liquide. Le taux de conversion des monomères dépasse alors 90 % en moins de 5 min. Les mesures de chromatographie d’exclusion stérique montrent la formation de longues chaines polymère (45000g/mol) et soulignent l’absence des dimères (HEMA)₂ ayant servis d’initiateurs de polymérisation. Cette seconde méthode de polymérisation s’est révélée extrêmement efficace pour synthétiser des hybrides pHEMA-TiO₂. Par rapport aux hybrides obtenus par voie classique à pression atmosphérique en utilisant des initiateurs de polymérisation thermique ou photonique, l’approche HP mise au point dans cette thèse permet de multiplier par un facteur trois la concentration de nanoparticules sans détériorer l’état de polymérisation de matériau. La sensibilité photonique des hybrides est ainsi augmentée sans dégradation des propriétés mécaniques. L’étude des propriétés photochromiques des hybrides montre que le rendement quantique de séparation des charges photo-induites et la capacité de stockage des électrons atteignent respectivement 15 % et 50% / The specific functional properties of the organic-inorganic hybrid materials depend on their microstructure and the nature of the interface between their organic and inorganic components. The production of hybrid materials with an optimum combination of mechanical and functional properties is a major problem in hybrid materials science. In this thesis we adress this issue by studing and proposing a new approach for synthesizing of photosensitive pHEMA-TiO₂ hybrid materials in wich inorganic nanoparticles are dispersed in a polymer. The method that we propose is based on the high pressure (HP) induced polymerization of the organic phase in the absence of a chemical initiator. We first observed the spontaneous polymerization of HEMA under static pressure. The polimerization process takes place in pressure range below the glass transition point (0.1-1.6 GPa) and after 41 days monomer conversion yield (CY) does not exceed 28%. The reaction may be significantly accelerated when the pressurized sample is irradiated in the UV range. We then developed an original approach based on compression-decompression cycle. During the compression step (>6.5 GPa) the biradicals formed from the excited monomers HEMA (T1) lead to the formation of small oligomers. The polimerization occurs in the second step when the sample decompressed at pressures between 0.1 and 2 GPa. The CY of 90% in less than 5 min is achieved. The new HP approach allows multiply by a factor of 3 the contration of nanoparticles in hybrids without damaging of their polimerization state. These hybrids exhibit a quantum efficiency of photoinduced charge separation of 15% and an electron storage capacity of 50%.

O titânio comercialmente puro (Ti-Cp) e suas ligas destacam-se como biomateriais metálicos devido a sua biocompatibilidade sendo amplamente utilizados. Buscando aprimorar o sucesso clínico dos implantes de Ti-Cp em longo prazo, é necessário revestir a sua superfície, proporcionando uma eficiente ancoragem mecânica do implante com o tecido ósseo. Dentre os diversos revestimentos superficiais destacam-se os revestimentos híbridos orgânicos-inorgânicos à base de precursores alcóxidos de silício, obtidos via processo sol-gel. Para que ocorra uma satisfatória adesão do revestimento no substrato, precisa-se levar em consideração a natureza e a preparação da superfície metálica antes da aplicação deste revestimento. Na etapa inicial do trabalho, pré-tratamentos superficiais foram propostos previamente à aplicação dos revestimentos buscando aumentar a aderência entre o titânio e este revestimento híbrido. Utilizou-se três diferentes pré-tratamentos na superfície do Ti-Cp: o "piranha" (ácido sulfúrico e peróxido de hidrogênio), o "kroll" (ácido fluorídrico, ácido nítrico e água) e o "hidróxido de sódio". Em sequência, aplicou-se por processo de dip-coating sobre as superfícies tratadas, um revestimento híbrido produzido a partir dos precursores alcóxidos de silício tetraetoxisilano (TEOS) e metiltrietoxisilano (MTES), obtido pelo processo de sol-gel. Em uma segunda etapa, sobre a superfície do Ti-Cp com o pré-tratamento superficial que proporcionou uma maior aderência do revestimento híbrido ao titânio, aplicou-se por dip-coating, um revestimento híbrido à base de precursores alcóxidos de silício TEOS e MTES com adição de partículas de hidroxiapatita buscando aprimorar a diferenciação celular sobre o revestimento híbrido. O pré-tratamento com o hidróxido de sódio promove o melhor resultado dentre os pré-tratamentos, pois o revestimento híbrido aplicado posteriormente apresenta recobrimento regular e adesão ao substrato de Ti-Cp. Os resultados morfológicos por MEV-FEG mostraram um revestimento híbrido com boa dispersão da hidroxiapatita e um recobrimento regular e adesão ao substrato de Ti-Cp. Nos resultados biológicos Ti-Cp revestido com TEOS/MTES com a presença de partículas de hidroxiapatita obteve uma adesão celular semelhante ao Ti-Cp sem tratamento. Porém este mesmo revestimento não propiciou a proliferação e diferenciação celular. Os resultados indicaram que a combinação de fatores como a sua superfície hidrofóbica (91°) e a presença da hidroxiapatita no revestimento tornou a superfície desorganizada, acarretando em uma superfície com comportamento desfavorável para o desenvolvimento das células-tronco mesenquimais. / Commercially pure titanium (cp-Ti) and its alloys stand out among the metallic materials due to their biocompatibility being widely used in biomaterials. In order to improve the clinical success of cp-Ti implants in the long term, it is necessary to coat the surface, providing an efficient mechanical anchoring of the implant with the bone tissue. Among the various surface coatings are the hybrid coatings based on silicon alkoxide precursors, obtained by the sol-gel process, however, considering the nature and the preparation of the metal surface prior to the application of this coating. In the initial stage of the work, surface pre-treatments were proposed prior to the application of the coatings seeking to increase the adhesion between the titanium and this hybrid coating. Three different pretreatments were used on the cp-Ti surface: "piranha" (sulfuric acid and hydrogen peroxide), "kroll "(hydrofluoric acid, nitric acid and water) and "sodium hydroxide". Subsequently, a hybrid coating produced by the tetraethoxysilane silicon (TEOS) and methyltriethoxysilane (MTES) precursors obtained by the sol-gel process was applied by the dip-coating process onto the treated surfaces. In a second step, on the surface of the cp-Ti with the surface pretreatment that gave a greater adhesion of the hybrid coating to the titanium, dip-coating, a hybrid coating based on precursors silicon alkoxides TEOS and MTES with the addition of hydroxyapatite particles to enhance cell differentiation on the hybrid coating. Pretreatment with sodium hydroxide promotes the best result among the pre-treatments, since the hybrid coating applied afterwards presents regular coating and adhesion to the cp-Ti substrate. The morphological results by SEM-FEG showed a hybrid coating with good dispersion of the hydroxyapatite and a regular coating and adhesion to the cp-Ti substrate. In the biological results Ti-Cp coated with TEOS / MTES with the presence of hydroxyapatite particles obtained a cell adhesion similar to Ti-Cp without treatment. However, this same coating did not promote cell proliferation and differentiation. The results indicated that the combination of factors such as its hydrophobic surface (91°) and the presence of the hydroxyapatite encapsulated in the coating rendering the surface disorganized led to a surface with unfavorable behavior for the development of mesenchymal stem cells.

Abstract This thesis conducts a comprehensive investigation of the of the physical chemistry related to the TEOS-based porous materials prepared by so-gel approach and develops the fast qualification technology for the hydrolysis and condensation reaction of sol-gel process. The porous materials were prepared by introducing a polymer polyethylene glycol (PEG) into sol-gel after different aging times and with different drying and annealing processes. The effects of pH and addition of PEG on sol-gel derived SiO2 powders for purification of ethanol are studied. The methods and results of this work provide valuable reference for the development of other functional materials such as low k dielectric materials. In the first part, the long-term behavior of the hydrolysis and condensation reaction of the tetraethoxysilane (TEOS) pre-solution at different pH values with and without addition of polyethyleneglycol (PEG) for various aging times was characterized by liquid 1H, 13C, and 29Si NMR spectroscopy.The experimental results demonstrate that alcohol was generated in the TEOS pre-solutions with and without addition of PEG at pH 3 and pH 9 after aging, implying the occurrence of hydrolysis and condensation. The rate of hydrolysis and condensation for the TEOS pre-solution at pH 3 was found to follow the trend of the pre-solution with PEG 2000 > pre-solution with PEG 200 > pre-solution without PEG. However, after adding PEG, the oxygen atom of the deprotonated silanol group (siloxy) of the hydrolyzed TEOS pre-solution at pH3 acted as a reaction center. The result indicates that the oxygen atom is more susceptible to electrophilic attack, resulting in an increased reaction rate. Consequently, the rate of hydrolysis and condensation for of the TEOS pre-solution at pH 9 follows a different order: pre-solution with PEG 200 > pre-solution without PEG > presolution with PEG 2000. The slowest reaction rate of the TEOS pre-solution when adding PEG 2000 is related to the tangled chains of PEG 2000 which sterically reduces the hydrolysis and condensation reaction. This work shows that the correlation between the pH and aging time on hydrolysis and condensation reaction of the TEOS pre-solution can be effectively monitored by liquid 1H NMR spectroscopy, supported by 13C and 29Si liquid NMR spectra. The data obtained should assist optimizing the pH, polymer type/size/concentration and the aging time in the preparation of polymer modified TEOS sols In the second part, SiO2 powders were prepared by the sol-gel in combination with oven-drying method before and after annealing.The experimental result demonstrates the rate of hydrolysis and condensation occurs at a fast rate in TEOS with and without adding PEG at pH3 than in any other pH levels. Because free space can lead to the vaporization of H2O, the ionization of ammonia decreases (i.e., reduction the amount of hydroxide ion), which arises from the rate of hydrolysis and condensation decreases when TEOS at pH9. After attaching PEG, the oxygen atom of the deprotonated silanol group (siloxy) for of the hydrolyzed TEOS pre-solution at pH 3 acted as a reaction center. The result indicates the oxygen atom is more susceptible to electrophilic attack, resulting in an increased reaction rate. Thus, a maximum in the powder yield is reached for TEOS pre-solution with and without adding PEG at pH 3. The SiO2 powder with adding PEG of higher molecular weight presents higher adsorption capacities, pertaining to a greater amount of hydrophilic hydroxyl groups of PEG with higher molecular weight. After annealing, the surface area of SiO2 powder prepared from the TEOS pre-solutions increases as compared with powder without adding PEG and enhances the adsorption of water. A potential absorbent SiO2 powders for producing purified ethanol suitable for fuel and industrial use, can be fabricated by using sol-gel route by careful selection of pH and PEG molecular weight. In addition, during the preparation and characterization of these materials, some interesting phenomena were observed, which are academically valuable. For instance, some samples show very narrow 1H MAS spectra and yet has high 1H-29Si CPMAS sensitivety. This phenomenon suggests us that CPMAS sensitivety may be improved by a new route, i.e., by properly preparing the sample so that CP efficiency is enhanced.

The objective of this thesis is to integrate the optical waveguide and single mode fiber in a passive alignment way on a silicon bench. This technique can reduce the complexity of packaging the individual components and increase yield of the module in order to achieve the goal of the mass production. In this module, buried waveguide structure was used for light guidance. A 1.31µm semiconductor laser was used as the input light source. Light signal launched by semiconductor laser is transferred through the buried waveguide into the single mode fiber. This module structure is consisted of two major parts, namely, the buried waveguide and the silicon bench. Buried optical Waveguide uses SO2 as the bottom cladding. Conventional photolithography procedures and etching technique were used to form a trench on the SiO2 cladding. The waveguide core was fabricated by coating the organic-inorganic hybrid materials into the trench. Finally, an organic-inorganic hybrid materials with a refractive index smaller than that of the core is used as the top cladding. The silicon benches were obtained by etching V-groove and saw-cutting U-groove on the silicon substrates for fixing the fiber. The patterning of buried waveguide and silicon V-groove were fabricated by a single optical mask procedure. Therefore accurate alignment between the waveguide and the single mode fiber can be obtained.

In this study, organic-inorganic hybrid materials were prepared from polyurethane and boehmite. It was achieved by polymerizing monomers in the presence of functional nano-particles of boehmite with cyanate groups. The produced polyurethane organic-inorganic hybrid materials with enhanced mechanical properties were used for coating applications. Plate-like boehmite nano-particles were produced by hydrothermal process from aluminum hydroxide which was first ground in a high energy ball-mill, and then, processed hydrothermally under pressure and high temperature in a reactor. The surface morphology and crystal structure of boehmite were investigated by Scanning Electron Microscopy and X-Ray Diffraction analyses, respectively. The molecular structures of boehmite particles were investigated by Fourier Transform infrared spectroscopy. Furthermore, Brunauer-Emmett-Teller analysis and Photon Correlation Spectroscopy analysis were carried out to determine the surface area and the size of particles. Then, plate-like boehmite nano-particles were functionalized by the reaction of their hydroxyl groups with 1,6-hexamethylene diisocyanate and 4,4&rsquo / -methylene diphenyl diisocyanate. Scanning Electron Microscopy, Fourier Transform Infrared Spectroscopy, Differential Thermal Analysis-Thermal Gravimetric Analysis, and elemental analysis were performed for both functionalized and non-functionalized particles to confirm the functionalization of the particles. The polyester polyol used in the production of polyurethane was synthesized from 1,4-butanediol and adipic acid (PE-PO-1), and phthalic anhydride (PE-PO-2). Molecular structure of the polyester polyols was confirmed by Fourier Transform Infrared Spectroscopy analysis and molecular weight of the polymers were determined by end group analysis. Then, the produced functionalized nano-particles and polyester polyols were used for producing polyurethane organic-inorganic hybrid materials. Furthermore, polyurethane polymer and polymer-nonfunctionalized boehmite organic-inorganic hybrids were also synthesized for property comparison. Hardness, impact resistance, scratch resistance, abrasion resistance, and gloss property of the samples were determined. It was observed that mechanical properties of organic-inorganic hybrid materials improved significantly. The hardness of the PU produced with PE-PO-1 increased from 82 to 98 Persoz, and the hardness of the PU produced with PE-PO-2 increased from 52 to 78 Persoz when one weight percentage functionalized boehmite was used. The impact resistance of the coatings was found to depend on the type of the polyols used in PU but not in the inorganic component. Therefore PE-PO-2 used PU has higher impact resistance than PE-PO-1 used PU. Scratch resistance of the coatings improved from 2B to 2H when using functionalized boehmite. Abrasion resistance of PUs produced with PE-PO-1 increased from 2 to 10 l/micrometer and abrasion resistance of PUs produced with PE-PO-2 increased from 12 to 20 l/micrometer by addition of functionalized boehmite.

O titânio comercialmente puro (Ti-Cp) e suas ligas destacam-se como biomateriais metálicos devido a sua biocompatibilidade sendo amplamente utilizados. Buscando aprimorar o sucesso clínico dos implantes de Ti-Cp em longo prazo, é necessário revestir a sua superfície, proporcionando uma eficiente ancoragem mecânica do implante com o tecido ósseo. Dentre os diversos revestimentos superficiais destacam-se os revestimentos híbridos orgânicos-inorgânicos à base de precursores alcóxidos de silício, obtidos via processo sol-gel. Para que ocorra uma satisfatória adesão do revestimento no substrato, precisa-se levar em consideração a natureza e a preparação da superfície metálica antes da aplicação deste revestimento. Na etapa inicial do trabalho, pré-tratamentos superficiais foram propostos previamente à aplicação dos revestimentos buscando aumentar a aderência entre o titânio e este revestimento híbrido. Utilizou-se três diferentes pré-tratamentos na superfície do Ti-Cp: o "piranha" (ácido sulfúrico e peróxido de hidrogênio), o "kroll" (ácido fluorídrico, ácido nítrico e água) e o "hidróxido de sódio". Em sequência, aplicou-se por processo de dip-coating sobre as superfícies tratadas, um revestimento híbrido produzido a partir dos precursores alcóxidos de silício tetraetoxisilano (TEOS) e metiltrietoxisilano (MTES), obtido pelo processo de sol-gel. Em uma segunda etapa, sobre a superfície do Ti-Cp com o pré-tratamento superficial que proporcionou uma maior aderência do revestimento híbrido ao titânio, aplicou-se por dip-coating, um revestimento híbrido à base de precursores alcóxidos de silício TEOS e MTES com adição de partículas de hidroxiapatita buscando aprimorar a diferenciação celular sobre o revestimento híbrido. O pré-tratamento com o hidróxido de sódio promove o melhor resultado dentre os pré-tratamentos, pois o revestimento híbrido aplicado posteriormente apresenta recobrimento regular e adesão ao substrato de Ti-Cp. Os resultados morfológicos por MEV-FEG mostraram um revestimento híbrido com boa dispersão da hidroxiapatita e um recobrimento regular e adesão ao substrato de Ti-Cp. Nos resultados biológicos Ti-Cp revestido com TEOS/MTES com a presença de partículas de hidroxiapatita obteve uma adesão celular semelhante ao Ti-Cp sem tratamento. Porém este mesmo revestimento não propiciou a proliferação e diferenciação celular. Os resultados indicaram que a combinação de fatores como a sua superfície hidrofóbica (91°) e a presença da hidroxiapatita no revestimento tornou a superfície desorganizada, acarretando em uma superfície com comportamento desfavorável para o desenvolvimento das células-tronco mesenquimais. / Commercially pure titanium (cp-Ti) and its alloys stand out among the metallic materials due to their biocompatibility being widely used in biomaterials. In order to improve the clinical success of cp-Ti implants in the long term, it is necessary to coat the surface, providing an efficient mechanical anchoring of the implant with the bone tissue. Among the various surface coatings are the hybrid coatings based on silicon alkoxide precursors, obtained by the sol-gel process, however, considering the nature and the preparation of the metal surface prior to the application of this coating. In the initial stage of the work, surface pre-treatments were proposed prior to the application of the coatings seeking to increase the adhesion between the titanium and this hybrid coating. Three different pretreatments were used on the cp-Ti surface: "piranha" (sulfuric acid and hydrogen peroxide), "kroll "(hydrofluoric acid, nitric acid and water) and "sodium hydroxide". Subsequently, a hybrid coating produced by the tetraethoxysilane silicon (TEOS) and methyltriethoxysilane (MTES) precursors obtained by the sol-gel process was applied by the dip-coating process onto the treated surfaces. In a second step, on the surface of the cp-Ti with the surface pretreatment that gave a greater adhesion of the hybrid coating to the titanium, dip-coating, a hybrid coating based on precursors silicon alkoxides TEOS and MTES with the addition of hydroxyapatite particles to enhance cell differentiation on the hybrid coating. Pretreatment with sodium hydroxide promotes the best result among the pre-treatments, since the hybrid coating applied afterwards presents regular coating and adhesion to the cp-Ti substrate. The morphological results by SEM-FEG showed a hybrid coating with good dispersion of the hydroxyapatite and a regular coating and adhesion to the cp-Ti substrate. In the biological results Ti-Cp coated with TEOS / MTES with the presence of hydroxyapatite particles obtained a cell adhesion similar to Ti-Cp without treatment. However, this same coating did not promote cell proliferation and differentiation. The results indicated that the combination of factors such as its hydrophobic surface (91°) and the presence of the hydroxyapatite encapsulated in the coating rendering the surface disorganized led to a surface with unfavorable behavior for the development of mesenchymal stem cells.