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1
Moitra, Nirmalya. "Silices hybrides fonctionnelles : matériaux dérivés d'alcaloïdes pour organocatalyse ; réactions "click" pour le sol˗gel." Thesis, Montpellier, Ecole nationale supérieure de chimie, 2011. http://www.theses.fr/2011ENCM0003.
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Cette thèse s'intéresse à la préparation de silices hybrides organique/inorganiques à base de fragments alcaloïdes cinchona, et à une nouvelle méthode de synthèse de précurseurs silylés hydrolysables via une réaction ‘click' de CuAAC. La première partie de ce travail est dédiée à une présentation bibliographique du domaine de la catalyse supportée sur matériaux hybrides, et est principalement focalisée sur l'organocatalyse supportée, un champ de recherche en plein développement. Dans la seconde partie, différentes méthodes d'immobilisation d'alcaloïdes dans une matrice de silice sont décrites, dans le but de les utiliser comme organocatalyseurs pour une réaction de décarboxylation asymétrique. La troisième partie est dédiée à une nouvelle méthode de préparation de précurseurs silylés via une réaction de CuAAC. Cette méthodologie montre un potentiel important pour la formation de nouveaux composés fonctionnels. Finalement, la synthèse de nanoparticules de silice mésoporeuse contenant des groupes azoture ou alcyne et leur post-fonctionalisation sont présentéesThis thesis deals with the preparation of organic-inorganic hybrid silica based on cinchona alkaloids fragments and with a new method of synthesis for hydrolysable silylated precursors via CuAAC “click” reactions. The first part of this work is dedicated to a bibliographic presentation of the area of supported catalysis on hybrid materials and is mainly focused on supported organocatalysis, an emerging area of research. In the second part, different methods for immobilization of alkaloids within a silica matrix are described aiming at using them as organocatalysts for an asymmetric decarboxylation reaction. The third part is devoted to a new method of preparation of silylated precursors by CuAAC “click” reactions. This methodology shows a high potential in the formation of new functional compounds. Finally the synthesis of mesoporous silica nanoparticles bearing azide or alkyne groups and their post-functionalization by CuAAC reactions are presented
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Hosokawa, Ricardo Shindi [UNESP]. "Delineação de padrões na superfície da poliamida por processo de plasma." Universidade Estadual Paulista (UNESP), 2016. http://hdl.handle.net/11449/147082.
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Neste trabalho foi investigada a possibilidade de se criar padrões regularmente distribuídos sobre a superfície da poliamida (PA), utilizando o processo de deposição de filmes em plasmas de baixa pressão. Para tal, um único procedimento foi empregado utilizando-se uma malha metálica comercial (60 μm) como máscara para delinear pilares na superfície da poliamida. Os plasmas de deposição foram gerados a partir de atmosferas contendo 70% de hexametildisiloxano (HMDSO) e 30% de oxigênio a uma pressão total de 23 Pa, já incluído o valor de 3 Pa referente à pressão de fundo. O plasma foi ativado pela aplicação do sinal de radiofrequência (13,56 MHz, 150 W) no suporte de amostras enquanto o eletrodo superior permaneceu aterrado. O tempo de deposição, t, foi alterado de 15 a 90 min. Na etapa inicial do trabalho o filme foi uniformemente depositado sobre o polímero sem a utilização de máscara. Uma segunda etapa de experimentos foi realizada, utilizando-se condições idênticas às anteriores, mas com o auxílio da trama metálica sobre as amostras para guiar a deposição do filme somente nos poros da máscara. Filmes organosilicones, compostos por estruturas granulares e com espessuras dependentes de t, foram uniformemente depositados sobre a PA quando a máscara não foi utilizada. A deposição do filme independentemente da condição de t, aumenta a rugosidade superficial e transforma a amostra inicialmente hidrofílica em hidrofóbica. Muito embora t afete de forma suave a composição química, estrutura molecular e a molhabilidade do filme, seu efeito na espessura da camada é substancial. Padrões na forma de pilares foram regularmente definidos na superfície da PA com a deposição do filme organosilicone e a utilização da máscara. A altura dos pilares cresce com t alcançando até 1 µm. Para os maiores valores de t empregados, as máscaras não atuaram efetivamente como sombra na região dos fios. Observou-se que a molhabilidade da superfície ficou estável com o tempo de envelhecimento e não foi afetada pelos padrões.
In this work it was investigated the possibility of creating patterns regularly distributed on the surface of the polyamide (PA), using the process of film deposition in low pressure plasmas. For such, a single procedure was employed using a commercial metallic mesh (60 μm) as a mask to delineate pillars on the polyamide surface. The depositing plasmas were generated from atmospheres containing 70% of hexamethyldisiloxane (HMDSO) and 30% of oxygen at a total pressure of 23 Pa, already included the amount of 3 Pa related to the background pressure. The plasma was activated applying a radiofrequency signal (13.56 MHz, 150 W) to the sample holder while grounding the topmost electrode. Deposition time, t, was changed from 15 to 90 min. In the initial stage of the work the film was evenly deposited on the polymer without the usage of mask. A second step of experiments was performed, using the same conditions as earlier, but with the aid of the metallic frame on the samples to guide the film deposition only in the pores of the mask. Organosilicones films consisting of granular structures and thickness dependent of t were evenly deposited on the PA when the mask was not used. The film deposition, independently of condition of t, increases the surface roughness and transforms the sample initially hydrophilic to hydrophobic. Although t affects smoothly the chemical composition, molecular structure and wettability of the film, its effect on the layer thickness is substantial. Patterns in the form of pillars were regularly defined on the surface of PA with the organosilicon film deposition and the usage of the mask. The height of the pillars grows with t reaching up to 1 micrometers. For higher values of t, the masks did not act effectively as shadow in the wire region. It was observed that the surface wettability was stable with the aging time and it was not affected by the patterns.
3
Noureddine, Achraf. "Approches Click en Chimie Sol-Gel." Thesis, Montpellier, Ecole nationale supérieure de chimie, 2014. http://www.theses.fr/2014ENCM0005/document.
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Nous visons dans ce travail de thèse à développer une méthodologie de fonctionnalisation par chimie click des silices hybrides synthétisées par voie sol-gel. La réaction click de cycloaddition azoture-alcyne catalysée au cuivre (CuAAC) offre une tolérance exceptionnelle pour les fonctions organiques en plus de conversions très élevées. Dans cette optique, nous avons mis en œuvre en premier lieu des matériaux clickables à base d'organosilice pure (organosilice à mésoporosité périodique (PMO) et silsesquioxanes pontés (BS)) qui ont permis une conversion quasi-quantitative de greffage par CuAAC. Nous avons ensuite utilisé cette particularité pour contrôler les propriétés de surface des BS en modifiant leur caractère hydrophile/lipophile. Dans le second axe de travail, nous nous sommes intéressés à l'apport de la chimie click pour la préparation de nanoparticules mésoporeuses de silice multifonctionnelles, dites mécanisées, pour des systèmes à délivrance contrôlée de principes actifsThe present work aims to develop a trustful methodology of functionalization for hybrid silica materials made by the sol-gel process using the copper-catalyzed alkyne-azide cycloaddition (CuAAC)Click reaction. This transformation can be highly useful in materials science thanks to its high conversions and the excellent functional group tolerance. In this prospect, we have synthesized fully clickable bridged silisesquioxanes and periodic mesoporous organosilica that show high extents of click grafting. CuAAC was then used for tailoring the surface of bridged silsesquioxane and fine-tuning the hydrophilic/lipophilic balance. Finally, the click reaction was used as an efficient way to obtain multiply functionalized mesoporous silica nanoparticles in order to make nanomachines for controlled delivery of cargo molecules
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Tran, Thanh Hien. "Couches minces copolymères plasma anti-buée élaboration et caratérisation : élaboration et caratérisation." Thesis, Le Mans, 2019. http://www.theses.fr/2019LEMA1012/document.
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Le travail de la thèse est focalisé sur l’ élaboration plasma d’un revêtement multicouches avec une couche supérieure anti-brouillard et une couche inférieure dite barrière sur un polycarbonate. L’ensemble des travaux est divisé en 3 parties: élaborations des deux monocouches barrière ou antibuée puis dépôt de la multicouche barrière - antibuée. La polymérisation plasma de la couche barrière est effectuée à partir d’un mélange de dioxygène et d’un précurseur organosilicié : l’hexaméthyledisiloxane ou le 2,4,6,8-tétraméthylcyclotétrasiloxane ou bien encore le triéthoxyfluorosilane. La caractérisation des couches minces obtenues repose sur la spectroscopie Infrarouge à Transformée de Fourier , la spectroscopie de photoélectrons X et la microscopie à force atomique. L’influence des conditions de dépôt plasma comme la puissance, la proportion monomère/dioxygène, le temps du dépôt sur la structure chimique et l’hydrophobicité de la surface des différents types de couches organosiliciées est étudiée. Les résultats de la perméation avec l’eau liquide ou le dioxygène montrent que la propriété barrière des couches organosiliciées non fluorées est meilleure que pour la couche fluorée. L’élaboration de copolymères anti-buée repose sur l’utilisation de combinaisons entre deux précurseurs hydrophile et hydrophobe en voie plasma pulsé. Les précurseurs tels que le 2-(diméthylamino)éthyl méthacrylate ou l’acide acrylique sont choisis pour leur hydrophile alors que le 1H,1H,2H-perfluoro-1-décène représente la partie oléophobe. La propriété anti-brouillard et sa stabilité à long terme après un vieillissement thermique ou en milieu humide est dépendante de leurs structure et morphologieThe PhD work is focused on the deposition of a multilayer coating with an anti-fog top layer obtained thanks to the plasma copolymerization of hydrophilic and hydrophobic monomers and an intermediate barrier layer, also obtained by plasma deposition on polycarbonate. The work is divided into 3 parts: the independently preparations of the two monolayers, barrier and anti-fogging ones, then the barrier-antifog multilayer deposition. The characterization of the thin films obtained is based on Fourier Transform Infrared Spectroscopy, X-ray photoelectron spectroscopy and atomic force microscopy.The barrier plasma-layer is issued from by the mixture of dioxygen and one of these three organosilicon precursors : hexamethyledisiloxane ; 2,4,6,8-tetramethylcyclotetrasiloxane ; triethoxyfluorosilane. The influence of the plasma conditions such as discharge power, monomer/dioxygen ratio, deposition duration on the chemical structure and the hydrophobicity of the different types of the organosilicon layers was studied. The results of permeation with liquid water or dioxygen show that the barrier property of the organosilicon layer is more efficient than that of the fluorinated layer. Anti-fog plasma-copolymer is synthetized from two hydrophilic and hydrophobic precursors deposited by pulsed plasma mode. The precursors such as 2-(dimethylamino) ethyl methacrylate and acrylic acid were selected for the hydrophilic part while the 1H, 1H, 2H-perfluoro-1-decene will be associated to the oleophobic part. The dependence of the chemical structure and the morphology of the anti-fog layers is studied according to the hydrophilic/oleophobic distribution and the deposition time
5
Nguyen, Thy Phuong. "Hybrides organiques-inorganiques organisés par 'liquid crystal templating' de précurseurs ioniques." Montpellier 2, 2009. http://www.theses.fr/2009MON20201.
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Une série des précurseurs contenant des sous-structures cationiques organiques à base d'entités imidazolium, guanidinium et ammonium ainsi que des précurseurs neutres contenant des sous-structures amines été synthétisé. Ces précurseurs ont été utilisés pour la synthèse de matériaux nanostructurés par des processus de 'liquid crystal templating'. Le processus la formation de matériaux nanostructurés par hydrolyse-polycondensation a été étudiée. La structuration des matériaux a été réalisée en particulier par l'utilisation de différents agents tensioactifs. Les facteurs principaux influençant sur la structuration des matériaux ont été étudiés pour trouver des conditions optimales pour la synthèse de matériaux nanostructurés. Des matériaux structurés présentant des architectures régulières hexagonaux 2D ont été obtenus avec différents précurseurs. Pour obtenir ces structures mésoporeuses organisées hexagonales, l'ajout d'un précurseur de silice s'avérait nécessaire dans le cas de précurseurs disposant d'une flexibilité élevée au niveau moléculaire. Pour d'autres précurseurs présentant une rigidité moléculaire importante, la formation de phases structurées a pu être réalisée sans ajout d'une source de silice. Finalement, nous avons développé une nouvelle stratégie de structuration qui met en jeu de interactions spécifiques entre des précurseurs cationiques et des tensioactifs anioniques. Ces matériaux nanostructurés contenant des sous-structures amine et ammonium présentent une grande surface spécifiques et une grande accessibilité des sites organiques. Ces propriétés font de ces matériaux des systèmes de choix pour des applications en catalyse ou en séparationA series of precursors containing organic cationic sub-structures such as imidazolium, guanidinium, and ammonium entities and several neutral precursors containing amino groups were successfully synthesized. These precursors were used for the synthesis of nanostructures silica hybrid materials or functionalized silica materials containing ionic substructures via template directed hydrolysis polycondensation procedures using various structure directing agents. The main factors influencing the structuring of the materials in the presence of different types of surfactant were studied and the optimal condition for the synthesis of nanostructured materials were found. 2D hexagonal structured materials have been obtained for different precursors both featuring high flexibility and high molecular size and high molecular rigidity. The addition of a silica source such as TEOS appeared to be necessary especially when rather flexible precursors were used. A new strategy was introduced permitting the structuring of materials bearing cationic substructures. This process is based on specific precursor-surfactant interactions and allowed the synthesis of 'periodic mesoporous organosilicas ' bearing amine and ammonium substructures with high specific surface areas and a high accessibility of the organic sites. Due to these features, these materials have large potential in the fields of catalysis and separation
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Voisin, Doria. "Structuration d’organosilices : assemblage covalent et auto-organisation de T8- silsesquioxanes octa-fonctionnalisés." Thesis, Montpellier, Ecole nationale supérieure de chimie, 2016. http://www.theses.fr/2016ENCM0017/document.
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Le présent travail vise la synthèse d’organosilices nano-structurées à partir de briques élémentaires de silsesquioxanes polyédriques fonctionnalisées (T8-POSS) de structure cube (RSiO1,5)8. L’assemblage de briques fonctionnelles T8-POSS a été étudié selon deux voies : par des interactions fortes en formant des liaisons covalentes et par des interactions faibles en formant des liaisons hydrogène.La première partie décrit la formation de réseaux hybrides covalents à partir de structure T8 POSS portant huit fonctions aldéhydes. La synthèse et la structure cristalline de ces « cubes » fonctionnalisés sont décrites et la réactivité des fonctions aldéhydes est examinée. La formation de liaisons C=N par réaction d’amines conduit à des réseaux tridimensionnels grâce à la formation de ponts organiques bis-imines joignant les unités silsesquioxanes. Bien que la formation d’imine soit réversible, les solides obtenus ne présentent pas d’ordre à longue distance. La formation de liaisons C=C, dans des conditions de synthèse non réversibles, par réaction de bis-ylures de phosphonium avec les aldéhydes a également été étudiée. Ces réactions de type Wittig engendrent la formation de réseaux hybrides amorphes contenant des sous-structures phenylène-vinylènes dotées de propriétés de fluorescence. La deuxième partie décrit la synthèse de nouvelles molécules de T8-POSS, possédant des fonctions organiques amines ou acides carboxyliques capables d’interactions intermoléculaires grâce à des liaisons hydrogène. Ces interactions permettent l’assemblage des dérivés du T8-POSS fonctionnalisés par huit fonctions acides carboxyliques en un réseau 3D ordonné. Les briques élémentaires T8- POSS s’auto-assemblent par dimérisation des fonctions acides pour engendrer des silices hybrides cristallines. Les structures ont été déterminées par diffraction de rayons X. Les fonctions acides carboxyliques sont intéressantes non seulement par leur capacité à former des liaisons hydrogènes mais également par leur aptitude à former des carboxylates métalliques. Ces derniers ouvrent des perspectives pour la formation de réseaux d’oragnosilices incorporant des métauxThe present work aimed at synthesising nano-structured organosilicas using polyhedral silsesquioxane building blocks (T8-POSS) having a cube structure. The assembly of T8-POSS building blocks to form a 3D network was studied in two ways: first by formation of strong covalent bonds and secondly by formation of weak hydrogen bonds.The first part described the formation of covalent hybrid networks from T8-POSS structures with eight aldehyde functional groups. The synthesis and crystal structure of these functionalised silsesquioxane cubes is described and the reactivity of the aldehyde groups is studied. The formation of C=N bonds upon reaction with amines lead to tree-dimensional networks upon formation of bis-imine bridges linking the silsesquioxane units. Despite the imine formation was reversible, the resulting solids were amorphous materials and exhibited no long distance order. The formation of C=C bonds, under non-reversible reaction conditions, was achieved by reaction of phosphonium bis-ylides. The Wittig type reactions generated amorphous hybrid networks containing bridging phenylene-vinylene substructures with fluorescence properties.The second part described the synthesis of new functionalised T8-POSS cubes with eight amine or carboxylic acid functions capable of intermolecular interactions by hydrogen bonding. It allowed the assembly of the octa-carboxylique acid cubes to form an ordered 3D hybrid network. The T8-POSS building blocks self-assembled upon dimerization of the acid groups and generated crystalline hybrid silicas. The crystal structures were determined by X-ray diffraction. The use carboxylic acid groups is interesting because of its ability to form hydrogen bonds and also because of its ability to form metal carboxylate derivatives. It could lead to hybrid metal organic silica frameworks
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El-Kaddar, Yousef Younis. "Organosilicon reaction mechanisms." Thesis, University of Sussex, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.375169.
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This thesis is concerned with the preparation and reactions of some highly sterically hindered organosilicon compounds, mainly of the type TeiSiMe2X where Tsi denotes the (Me3Si)3C group. The first detailed study of the reactions of TsiS1Me20CN has shown that reactions with NaN3 in MeOH or KSCN or KOCN in MeCN give exclusively the corresponding TsiSiMe2X compounds (X = N3, NCS, or NCO), whereas those with other salts, viz. LiCl, CsF, KSCN, and KOCN, give the TsiSiMe2X species along· with other products, including in many cases TsiSiMe2NCO and TsiSiMe20H (from traces of water), and (in MeOH) TsiSiMe20Me. The reaction with MeOH alone was never found to give less than 10% ot TslSiMe20H, along with the expected TsiSiMe20Me, however carefully the MeOH was dried. The extreme sensitivity of the cyanate towards water was illustrated by the fact that the rate ot solvolysis in 'dry' MeOH was increased by~. 90% by addition of 0.05 vol-% of H2o, and the hydroxide was the sole product, whereas the rate for the triflate TsiSiMe2- OS02CF3 was increased by only 13% and the product was a 60:40 mixture of TsiSiMe20Me and TsiSiMe20H. The rate constant for the triflate increased linearly with the water concentration but that of the cyanate did not. The presence of NaOMe in MeOH led to rapid isomerization of the cyanate to the isocyanate, TsiSiMe2NCO, with the rate of isomerization being proportional to the base concentration: a possible explanation of this effect of base is suggested. Isomerization catalysed by ICI in CC14 was found to be of ca. second order with respect to both the cyanate and the IcI: A detailed kinetic study has been carried out of the the reactions of TsiSiMe2X compounds, with X c I, Br, Cl, or ON02' with various alkali metal salts, MY, viz. NaN3' CsF, KSCN, and KOCN in MeOH and with KSCN in MeCN. For X • I, Br, or Cl, the reactions have been shown to be much more complex than was previously thought, the compounds TsiSiMe20Me, TsiSiMe20H, and (Me3Si}2CHSiMe2oMe commonly being formed along with TsiSiMe2Y. The order of effectiveness of the salts in the formation of TsiSiMe2Y is CsF > NaN3 > KSCN > KOCN, except that for X - I the order for CsF and NaN3 is reversed. Approximate values of the activation parameters have been obtained: the activation entropies have very high negative values, consistent with formation of a very crowded transition state. The nitrate is markedly more reactive even than the iodide, and gives cleaner conversions into TsSiMe2Y compounds: the activation energies are much lower and the activation entropies much more negative than those tor the halides. Reactions of the compounds (Me3Si)2C(SiMe2H)(SiMe2Cl) with alkali metal salts have been shown to be much faster than those of TsiSiMe2Cl, casting doubt on an earlier suggestion that the ease of solvolysis of the former chloride might be due to anchimeric assistance by y-H.
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Bo, Yingjian. "Methods in organosilane assembly." Diss., Temple University Libraries, 2012. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/213502.
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ChemistryPh.D.
Dialkylsilanediols are a novel class of non-hydrolyzable analogues of the tetrahedral intermediate of amide hydrolysis, shown to be good inhibitors of HIV-1 protease, angiotensin converting enzyme (ACE), and thermolysin. An impediment to utilization of these silanediol structures, however, has been the methods for their assembly. This research describes the reductive lithiation of hydridosilanes and alkoxysilanes, and the use of the resulting silyl anions to develop efficient methods to synthesize silanediol precursors. In the first part of research, lithiation of hydridosilanes was studied. As part of this study, a simple 1H NMR method was developed for monitoring and analyzing the progress of lithiation. In addition, this method was converted to a titration for silyllithium reagents using BHT as an internal standard. Silanediols 107 and 177 are analogues of a potent chymase inhibitor, NK-3201 (82). In the second part, diphenylsilanes 108 and 170, precursors to silanediols 107 and 177, were synthesized using addition of silyllithium to sulfinimine 113 as a key step. In the third part, lithiation of alkoxysilanes was studied. (Si,O)-Dianions, generated from lithiation of silane alcohol 175 or 2,2-diphenyl-1-oxa-2-silacyclopentane (225), were reacted with a wide variety of electrophiles to give potentially useful silicon-containing building blocks. Addition of the (Si,O)-dianion 284 to sulfinimines gave silanediol inhibitor precursors with full control of stereochemistry. In the last part, a new method featuring 1,1-diphenyl-2-azaallyllithium chemistry were utilized to synthesize a series of protected α-amino silanes 323, 329 - 331.
Temple University--Theses
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Mun, Ellina A. "Functionalised organosilica nanoparticles : synthesis, mucoadhesion and diffusion." Thesis, University of Reading, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.659018.
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Organosilica nanoparticles, due to their versatile properties, attract considerable attention for pharmaceutical applications. The first chapter of this thesis gives an introduction to organosilica materials and traditional methods of their synthesis, provides a literature review on functionalisaUon of silica nanoparticles, in particular PEGylation, and describes recently investigated routes of their application in pharmaceutical science. This is followed by a brief description of methods and techniques used in the current study for synthesis and characterisation of organosilica nanoparticles. Chapter 3 represents a novel size-controlled method of synthesis of thiolated and PEGylated organosilica nanoparticles from 3-mercaptopropyltrimethoxysilane (MPTS) using various organic solvents as media. The mechanism of the nanoparticle formation is proposed, the dependence of nanoparticles size on solvent's dielectric constant is determined, and other factors affecting the nanoparticle size are investigated. Thiol-groups on the surface of organosilica nanoparticles are available for a direct conjugation. Therefore, their surfaces were funcUonalised with two types of fluorescent dyes and PEG maleimide of two molecular weights (750and 5000 Oa). Additionally, polymer- and surfactant-templated mechanisms of MPTS nanoparticle formaUon are reported. The synthesis chapter is followed by studying the properties of thiolated and PEGylated organosilica nanoparticles. Mucoadhesive properties of silica nanoparticles were investigated using a newlyintroduced in vitro method assessing their retention ability on the urinary bladder by the means of fluorescence microscopy. The main factors affecting mucoadhesive properties of MPTS nanoparticles were revealed and thiolated nanoparticles were demonstrated to be promising mucoadhesive materials for intravesical drug delivery. PEGylated nanoparticles were found to be less mucoadhesive which led to the hypothesis of providing better permeation by PEGylation. This was considered in the subsequent chapter (chapter 5), studying the barrier functions of the cornea using thiolated and PEGylated nanoparticles. The "whole eye" in vitro method combined with the fluorescence microscopy demonstrated a good permeation of the latter through de-epithelialised ocular tissue into the stroma. This revealed the interaction of nanoparticles with the corneal surface to be a more impcrtant factor than the particle size, determining their permeation ability. As most organs of the human body are covered with biological hydrogels, the ability of silica nanoparticles to permeate through biological tissues has risen an interest in studying their capability to diffuse through such gels. Therefore, the diffusion of thiolated and PEGylated nanoparticles in different polymer solutions, which were selected as prototypes of biological hydrogels, was studied using NanoSight tracking analysis with fluorescent detection. The main factors affecting the diffusion of organosilica nanoparticles were revealed, and it was demonstrated that the presence of strong attractive interactions between the nanoparticles and macromolecules present in solutions can hamper the diffusion. This was followed by studying biocompatible properties of organosilica nanoparticles using an alternative to traditional methods, a slug mucosal irritation test, revealing their non-irritant nature. Finally, the general results of the current study are summarised and discussed in the last chapter of the thesis, proposing plans for the future work and expansion of the investigations on organosilica nanoparticles presented so far.
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Rahmani, Saher. "Élaboration de nanoparticules de silice mésoporeuse et d'organosilice pour des applications en nanomedecine." Thesis, Montpellier, 2017. http://www.theses.fr/2017MONTT190.
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Ces travaux de thèse sont dédiés à l’élaboration, la caractérisation et l’application des nanoparticules de silice mésoporeuse (MSNs) et d’organosilice (PMOs). Ces nanomatériaux qui font l’objet d’un grand intérêt dans la communauté scientifique, présentent des propriétés intéressantes telles que: une surface spécifique élevée, le contrôle de la morphologie, la porosité ajustable et enfin la facilité de fonctionnalisation de leur surface par des groupes fonctionnels. Dans cette thèse, deux familles de nanoparticules ont été étudiées : les nanoparticles de silice mésoporeuse (MSNs) et les nanoparticules d’organosilice.Premièrement, les MSNs synthétisées avec une taille de 200 nm et une surface spécifique de 810 m2/g ont été fonctionnalisées d’une manière covalente avec des antioxydants, un polyphénol l’acide caféique (CAF) qui est lié par sa fonction acide (-COOH) à une fonction amine (préalablement greffée sur la silice), ou un flavonoïde la ruine (RUT) qui est liée par l’isocianatopropylthrietoxysilane comme intermédiaire silicique. Les antioxydants ont été greffés afin de diminuer le stress oxydant. Les effets cellulaires sont étudiés sur deux lignées, une lignée de cellules issues d’un carcinome colo-rectal (lignée Caco-2) et une lignée tumorale de la peau (lignée HaCaT).Dans une deuxième partie, nous avons étudié l’influence de l’ajout d’un co-solvant «éthanol» au cours de la synthèse sur la morphologie des nanoparticules de silice mésoporeuse qui entraine la formation de nanoparticules de forme bâtonnet (MSNR) ainsi que le changement de structure de la poosité. Par la suite, les NPs de forme sphérique MSNA et les NPs de forme bâtonnet MSNR ont été chargées par la doxorubicine (DOX) et testées in vitro sur des cellules MCF-7.De plus, les synthèses de nanoparticules d’organosilice ont été réalisées. Ces nanomatériaux sont exclusivement synthétisés à partir de bis (3-méthoxysilyl propyl) -N-méthylamine et bis (triéthoxysilylpropyl) amine. Tout d'abord, la synthèse des NPs d’organosilice à cavité (HPONP) est decrite. Les HPONP ont été utilisés alors pour la délivrance de méthotrexate dans des cellules MCF-7. Deuxièmement, la synthèse d'autres types de NP d’organosilice (HMONP) obtenus par condensation du précurseur de bis (3-méthoxysilyl propyl) -N-méthylaminea été étudiée. Afin d'élargir la cavité des NP, nous avons signalé l'utilisation de TEB comme agent gonflement conduisant à la synthèse des HMLONP à large cavité. La morphologie et les compositions des NP ont été complètement caractérisées par diverses techniques et la délivrance de pepstatine à partir de HMLONP est envisagée. Pour ajouter une biodégradabilité aux nanocarriers, des nanoparticules mixtes ont été synthétisées par condensation de la bis (3-méthoxysilyl) propylméthylamine et du bis [3-(triéthoxysilyl) propyl] disulfure. Différentes nanoplatformes ont été conçues et entièrement caractérisées. La biodégradabilité a été évaluée dans des conditions quasi physiologiques. En outre, la voie de synthèse a été modifiée pour concevoir des nanoparticules d'organosilice à base d'éthylène ou de porphyrine. Ces nanoparticules ont été testées in vitro avec des cellules de cancer du sein et utilisées pour la délivrance de méthotrexate et de gemcitabine monophosphate.Enfin, on a décrit les nanoparticules organosilice de type cœur coquille. La coquille de ces nanoparticules obtenue par condensation du bis- (triéthoxysilyl) éthane et du bis (3- (triéthoxysilyl) propyl) tétrasulfure. Ces nanoparticules biodégradables du fait des groupements tetrasulfure ont été testées in vitro avec des cellules de cancer du sein pour l'imagerie et la délivrance d’un anticancéreuxThis work is dedicated to the development, characterization and application of nanoparticles of mesoporous silica (MSNs) and organosilica (PMOs) nanoparicles. Silica nanoparticles became the subject of intense research worldwide for many reasons: their unique chemical and physical characteristics, high biocompatibility, various shapes ranging from spheres to rods with tunable diameter, easily functionalizable surface, and the ability to be used as a shell on different type of inorganic nanoparticles such as gold, iron oxide, lanthanide nanoparticles. In this dissertation mesoporous silica NPs and organosilica NPs have been designed, optimized and fully characterized. These two types of silica NPs have been applied for biological applications (drug delivery and bioimaging).First, mesoporous silica nanoparticles (MSNs) were designed and were covalently coated with antioxidant molecules, namely, caffeic acid (MSN-CAF) or rutin (MSN-RUT), in order to diminish the impact of oxidative stress induced after transfection into cells. Two cellular models involved in the entry of nanoparticles in the body were used for this purpose: the intestinal Caco-2 and the epidermal HaCaT cell lines. Rutin gave the best results in terms of antioxidant capacities preservation during coupling procedures, cellular toxicity alleviation, and decrease of ROS level after 24 h incubation of cells with grafted nanoparticles.Secondly, we studied the control of the shape of MSNs by the addition of ethanol (EtOH) as cosolvent. Spherical (MSNA) or Rod MSNs (MSNR) were obtained, and then loaded loaded with doxorubicin and incubated with MCF-7 breast cancer cells. MSNA and MSNR particles were efficient in killing cancer cells but their behaviour in drug delivery was altered on account of the difference in their morphology.Then, the syntheses of new organosilica nanoparticles are reported. These nanomaterials are exclusively synthesized from bis (triethoxysilylpropyl) amine (BTSPA), bis (3-methoxysilyl propyl) -N-methylamine (BMSPMA) and bis- (triethoxysilyl) ethane precursors. First, it is reported the synthesis of hollow organosilica NPs (HPONPs) obtained through the condensation of bis (triethoxysilylpropyl) amine precursor by sol-gel process. HPONPs were used then for methotrexate delivery in MCF-7 cells. Secondly, it is reported the synthesis of other types of hollow organosilica NPs (HMONPs) obtained through the condensation of bis (3-methoxysilyl propyl) -N-methylamine precursor. In order to enlarge the cavity of NPs, we reported the use of TEB as swelling agent leading to the synthesis of HMLONPs. The morphology and the compositions of the NPs were fully characterized by various techniques and the pepstatin delivery from HMLONPs are under considaration. To add biodegradability to the nanocarriers, mixed nanoparticles were synthesized through the condensation of bis (3-methoxysilyl) propyl methylamine and the bis [3-(triethoxysilyl) propyl] disulfide. Different nanoplatforms were designed and fully characterized. The biodegradability was assessed in near-physiological conditions. Furthermore, the synthesis pathway was modified to design ethylene-porphyrin based organosilica nanoparticles. These nanoparticles were tested in vitro with breast cancer cells and used for methotrexate and gemcitabine monophosphate delivery.Finally, gold core shell mixed organosilica nanoparticles were described. The mixed shell of these nanoparticles was obtained by the co-condensation of bis- (triethoxysilyl) ethane and the bis (3-(triethoxysilyl) propyl)tetrasulfide. These biodegradable nanoparticles were tested in vitro with breast cancer cells for photon fluorescence imaging and core shell NPs were studied for drug delivery
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Trussell, Stephen John. "Transition metal-mediated organosilicon chemistry." Thesis, Imperial College London, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.298136.
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Kwak, Young-Woo. "Isomerization Reactions in Organosilicon Chemistry." Thesis, North Texas State University, 1985. https://digital.library.unt.edu/ark:/67531/metadc332336/.
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Dimethylsilene, generated from the thermal gas phase reaction of 1,1-dimethyl-1-silacyclobutane, reacts with alkynes to produce silacyclobutenes or acyclic silanes. The temperature dependence of the product ratios have been determined and the relative reactivities of three different alkynes toward the 1,1-dimethylsilene has been determined. 1-Hydrido-1-methylsilene has been generated by gas phase thermal decomposition from three different precursors. Trapping studies with butadiene and trimethylsilane lead to products expected from dimethylsilylene. The most plausible explanation for these observations is that hydridomethylsilenes undergo a facile isomerization to divalent dimethylsilylene. Cycloaddition of 1,1-dimethylsilene to allene at 600°C in a flow vacuum pyrolysis system affords the first synthesis of 2-methylene-1,1-dimethylsilacyclobutane and smaller amounts of six other products. For static pyrolysis at 421°C, the 2-methylene-1,1-dimethyIsilacyclobutane isomerizes to 1,1-dimethylsilacyclopentenes. The kinetics of gas phase thermal decomposition of cyclopropyltrimethylsilane has been studied over the temperature range, 689.6-751.1 K at pressures near 14 torr. The Arrhenius parameters for formation of allyltrimethylsilane are k_1(sec^-1)=10^14.3 ± 0.1 exp(-56.5 ± 0.2 kcal mol^-1/RT) and those for the formation of E- and Z-1-propenyltrimethyIsilane are k_2(sec^-1)=10^14.9 ± 0.3 exp(-61.9 ± 0.8 kcal mol^-1/RT). The difference between activation energies has been interpreted in terms of anchimeric assistance or the β effect of the silicon atom. The syntheses of 3-trimethylsilyl-1-pyrazoline and 1-trimethyl-2-pyrazoline are described. The thermal decomposition of either pyrazoline affords four different products along with elimination of a nitrogen molecule. It was suggested that the relative rates of methylene-hydrogen migration to radical centers α and γ to silicon are approximately equal. The thermal isomerization of 3-trimethylsilyl-1-pyrazoline to 1-trimethylsilyl-2-pyrazoline has been investigated kinetically at 65°C by proton NMR spectroscopy and the reverse reaction has been detected by gas phase pyrolysis.
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Jahns, Mandy [Verfasser]. "Nanoporöse Organosilica-Materialien für biomedizinische Anwendungen / Mandy Jahns." Hannover : Gottfried Wilhelm Leibniz Universität Hannover, 2019. http://d-nb.info/1190283433/34.
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Hughes, K. J. "Chemistry of gaseous organosilicon reactive intermediates." Thesis, University of Leicester, 1987. http://hdl.handle.net/2381/33745.
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Chapter one provides a brief history and current state of knowledge of the chemistry of organosilicon reactive intermediates relevant to this thesis. Chapter two outlines the experimental techniques used in the majority of work carried out in this thesis. Chapter three describes an experimental investigation of the pyrolysis of 4-dimethylsilylbut-l-ene and 5-dimethylsilylpent-l-ene, with and without excess methylchloride as a silyl radical trap. The results of computer modelling of the pyrolysis of 4-dimethylsilylbut-1-ene with excess methylchloride are described, in which information concerning the isomerisation of an alpha-silyl radical to a silyl radical via a hydrogen shift is obtained. Chapter four describes the results of an experimental investigation of the reactions of dimethylsilene and dimethylsilylene with anions. Chapters five and six contain the results of computer modelling of three related pyrolysis mechanisms composed of complex series of unimolecular rearrangements of silylenes, silenes, disilenes and disilacyclopropanes. Chapter seven describes an experimental determination of Arrhenius parameters for the trapping of dimethylsilene by butadiene, together with the results of pyrolysis of butadiene adducts of methylsilene, dimethylsilene and dimethylsilylene. Chapter eight is an experimental investigation of the pyrolysis of cis and trans dimethy1(1-propenyl)vinylsilane with excess 2,3-dimethylbutadiene as a silylene trap. Interpretation of the results as a cis-trans isomerisation and decomposition of the cis isomer via a silacyclopropane intermediate are reinforced by the results of computer modelling of both systems. Chapter nine describes an experimental investigation of the pyrolysis of 1, 2-dimethyldisilane with and without butadiene as a silylene trap. Computer modelling of the pyrolysis with the absence of butadiene is used to clarify the pyrolysis mechanism. Chapter ten is an experimental investigation of the pyrolysis of silacyclobutane and methylsilacyclobutane with excess butadiene to trap silylene intermediates and thus suppress secondary decomposition. Arrhenius parameters for the primary decomposition pathways are determined.
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Li, Yan. "Periodic mesoporous organosilicas with functional chromophores." Diss., Ludwig-Maximilians-Universität München, 2012. http://nbn-resolving.de/urn:nbn:de:bvb:19-173286.
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Jiang, Jianxiong. "Coordination and reactivity in organosilicon compounds." Thesis, Open University, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.291298.
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Gage, David Maxwell. "Fracture of nanoporous organosilicate thin films /." May be available electronically:, 2008. http://proquest.umi.com/login?COPT=REJTPTU1MTUmSU5UPTAmVkVSPTI=&clientId=12498.
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Yeh, Li-Tain. "Novel synthetic routes to organosilicon species." Case Western Reserve University School of Graduate Studies / OhioLINK, 1991. http://rave.ohiolink.edu/etdc/view?acc_num=case1055525594.
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Terpstra, Andrea Susanne. "Chiral nematic mesoporous organosilica materials templated with cellulose nanocrystals." Thesis, University of British Columbia, 2017. http://hdl.handle.net/2429/64160.
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Shu, Ronghua 1962. "Some novel organosilane reactions catalyzed by titanocenes." Thesis, McGill University, 1998. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=35941.
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This thesis presents some novel organosilane reactions catalyzed by titanocenes.Heterodehydrocoupling between silanes and phosphines has been accomplished with titanocenes, as catalysts. The reaction has the characteristics of high yield and high selectivity and can be carried out under mild conditions. Monophosphinosilanes and diphosphinosilanes can be selectively obtained from the reactions of secondary phosphines andsilanes. Primary phosphines react with primary silanes to produce 1,3,5-triphospha-2,4,6-trisilacyclohexanes. A two-catalytic-cycled mechanism is proposed with titanocene hydride as the key catalytic species.
Hydrosilation/hydrogenation of some aromatic N-heterocycles (namely pyridine, 3-picoline, 4-picoline, 3,5-lutidine, and quinoline) has been achieved with titanocene derivatives as catalysts. A variety of hydrosilated/hydrogenated products, either fully or partially saturated, may be produced depending on conditions. A reaction mechanism is proposed based on isolated and structurally characterized pyridine titanocene complexes, on the effects of substituent on the rates, and on H/D exchange studies. It is suggested that a key step in the hydrogenation/hydrosilation reaction is the formation of a mono-eta 1(N) complex between the pyridine ring and the titanocene silyl complex. It is proposed that the rate determining step is an intramolecular insertion of -N=C- into the Ti-Si bond. If the strong coordination or the intramolecular insertion is prohibited by either steric effects or electronic effects, or if the complex is of too high stability, no hydrogenation/hydrosilation product is obtained. Extensive H/D exchange at the 2- and 6-positions of the pyridine is attributed to a reversible ortho-metallation of pyridine in a Ti-H complex.
Cp2TiMe2 catalyzed hydrosilation/hydrogenation reactions of nicotinates, ethyl benzoate, and lactones have been studied. With ethyl nicotinate as the substrate, the hydrosilation occurs on the ring to give ethyl N-(methylphenylsilyl)-1,6-dihydronicotinate as the only product. No reaction at the ester group is observed. However, when the substrate is ethyl isonicotinate, ethyl 2-methylnicotinate or ethyl 6-methylnicotinate, the hydrosilation/hydrogenation only occurs at the ester groups and the carboalkoxy group is tranformed into either a silyl ether group or an alkyl group.
Copolymers can be produced from the titanocene catalyzed ring opening hydrosilation/hydrogenation reactions of lactones and PhMeSiH2. A key intermediate in these reactions, Cp[mu-(eta1:eta 5-C5H4)](THF)Ti(mu-H)TiCp 2, is isolated and well characterized by x-ray crystallography. The successful isolation and characterization of this product provides the first direct evidence to support the involvement of Cp2Ti in numerous Cp2TiMe2 catalyzed reactions in addition to correcting an earlier incorrect assignment of the structure of this frequently cited compound.
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Shu, Ronghua. "Some novel organosilane reactions catalyzed by titanocenes." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape7/PQDD_0022/NQ50260.pdf.
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Adams, Audrey Natasha Natalia. "The durability of organosilane pretreated adhesive joints." Thesis, Imperial College London, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.251962.
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Sohal, Wazir Singh. "The synthesis of chemistry of organosilicon cations." Thesis, Imperial College London, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.405220.
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Mehreteab, Tesfamariam. "Preparation of mesoporous Ti - Organosilicate epoxidation catalysts." DigitalCommons@Robert W. Woodruff Library, Atlanta University Center, 2009. http://digitalcommons.auctr.edu/dissertations/85.
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Following the methodology used in sol—gel chemistry to functionalize amorphous silica, organic functionalized mesoporous silica were prepared by the co-condensation of tetraethoxysilane and organoalkoxysilanes in the presence of surfactant templates. A series of titanium catalysts containing Ti-MCM-41 with different bridging and pendant organic functional groups (such as methyl triethoxysilane (MTEOS), phenyl triethoxysilane (PTEOS), diphenyl triethoxysilane (DPTEOS), bis (triethoxysilyl) ethane (BTSE), 1,4 bis(triethoxysiyl) benzene (BTSB), bis( triethoxysilyl) biphenyl (BTSDP) and two catalysts with different organic-inorganic ratios (90% TEOS with 10% phenyl, 70% TEOS with 30% phenyl) were synthesized. The catalysts were characterized by elemental analysis, XRD, FTIR, UVDRS, by solid state 13C and 29Si MAS NMR, and BET surface area analysis. The catalytic activities of the synthesized materials were evaluated for epoxidation of cyclohexene with TBIIP. The materials yielded improved conversion compared to the conversion results obtained from the traditional titanium containing mesoporous silica (Ti-MCM-41). The hydrophobic character of the synthesized catalysts was tested in the epoxidation of cyclohexene by using wet TBIIP. Ti-MCM41 with bridged organosilane showed almost the same conversion in the presence of water, while for Ti-MCM-41 with organosilane pendant groups. conversion decreased almost 36%. This implies that the silylation of the surface ofTi-MCM4I protected the active sites. The effect of substrate: oxidant molar ratio in these reactions were studied and high conversion, high selectivity were achieved at 1:1 molar ratio.
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Whittaker, Stephen Mark. "Some chemistry of sterically hindered organosilicon compounds." Thesis, University of Salford, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.239973.
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Wang, Wenhui. "Preparation and characterization of periodic mesoporous organosilicas." Thesis, University of Ottawa (Canada), 2004. http://hdl.handle.net/10393/26798.
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Periodic mesoporous organosilicates (PMOs) are hybrid materials whose framework is comprised of alternating organic and inorganic species. These materials are prepared via supramolecular templating assembly using bridged silsesquioxanes (RO)3Si-R'-Si(OR) 3 as precursors, and surfactants as templates. This thesis is devoted to the preparation and characterization of phenyl- and ethenylene-bridged PMOs. The phenylene-containing precursor (bis(triethoxysilyl)benzene was synthesized by Barbier-Grignard reaction, whereas the ethylene derivative bis(triethoxysilyl)ethylene was prepared by self-metathesis reaction. They were characterized by 1H and 13C NMR, and mass spectrometry.
The corresponding mesoporous materials were prepared using these precursors in the presence of different types of surfactants including oligomeric alkyl polyethylene oxide, triblock polyalkylene oxide copolymer and alkyltrimethylammonium surfactants. To obtain highly ordered mesoporous organosilicates, different synthesis conditions were employed and optimized. All materials were characterized using XRD, TEM, SEM, nitrogen adsorption, 29Si and 13C solid state NMR. In addition, some post-synthesis reactions using these materials were investigated.
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Voß, Rebecca. "Mesoporous organosilica materials with amine functions : surface characteristics and chirality." Phd thesis, Universität Potsdam, 2005. http://opus.kobv.de/ubp/volltexte/2005/528/.
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In this work mesoporous organisilica materials are synthesized through the silica sol-gel process. For this a new class of precursors which are also surfactant are synthesized and self-assembled. This leads to a high surface area functionality which is analysized with copper (II) and water adsorption.Im Rahmen dieser Arbeit werden mesoporöse Amin-funktionalisierte Organo-Silikate durch den Silika Sol-Gel Prozess hergestellt. Dabei werden neue Alkoxysilyl-Precursoren synthetisiert und condensiert die die gewünschte Funktion auf die Oberfläche dirigieren. Herstellt werden primäre, secundäre und chirale Amine. Die Oberflächenfunktionalität wird mit Kupfer (II) und Wasser Adsorption analysiert.
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Gehring, Julia Johanna [Verfasser]. "Mesoporous organosilica nanoparticles as antibacterial coating materials / Julia Johanna Gehring." Konstanz : Bibliothek der Universität Konstanz, 2016. http://d-nb.info/1118316541/34.
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Voss, Rebecca. "Mesoporous organosilica materials with amine functions surface characteristics and chirality /." [S.l. : s.n.], 2005. http://deposit.ddb.de/cgi-bin/dokserv?idn=975976362.
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Van-Straaten, Manon. "Dépôt de films minces de poly(méthacrylates) par iCVD : des mécanismes de croissance à la Polymérisation Radicalaire Contrôlée." Thesis, Lyon, 2019. http://www.theses.fr/2019LYSE1154.
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Les récentes avancées dans les micros et nanotechnologies ont nécessité le développement de nouvelles techniques de synthèse de films minces de nouveaux matériaux. Parmi eux, les polymères possèdent des propriétés intéressantes, notamment pour des domaines comme la microélectronique ou le biomédical. Pour pallier ce besoin, les techniques de dépôt de vapeur chimique (Chemical Vapor Deposition, CVD) se sont multipliées. Ces travaux portent sur la synthèse de couches minces de poly(méthacrylates) par un une nouvelle méthode de dépôt chimique en phase vapeur par une polymérisation amorcée in-situ ou initiated Chemical Vapor Deposition (iCVD). Cette technique possède de nombreux avantages parmi lesquels se trouvent ses conditions opératoires douces (absence de solvant, emploi de faibles températures), sa versatilité et sa conformité. Afin de mieux comprendre le procédé de synthèse des films minces de polymères par iCVD, une partie de ces travaux de thèse concerne l’étude de la cinétique de croissance des poly(méthacrylates). Une cinétique en deux régimes a été identifiée pour les deux polymères. Les analyses microscopiques et macroscopiques de couches minces issues des deux régimes ont permis la proposition d’un modèle de croissance. Le premier régime, au début de la croissance, est caractérisé par une faible vitesse de dépôt et des polymères de faibles masses molaires. Lorsque le second régime est atteint, la vitesse de dépôt est plus importante et devient constante. Les chaînes synthétisées possèdent des masses molaires plus élevées. Ce changement a pu être expliqué en mettant en avant la capacité du film en formation à se gorger de monomères, ce qui augmente la concentration locale de monomères. La cinétique de croissance des poly(méthacrylates) a aussi été étudiée sur des sous-couches de polymères et d’organosiliciés poreux. L’iCVD s’est révélée être une méthode capable de remplir de manière quasiment instantanée les pores nanométriques d’une couche mince. De plus, pour obtenir un meilleur contrôle des polymères synthétisés par iCVD au niveau de leur architecture macromoléculaire ou de leur masse molaire, la mise en place d’une technique de polymérisation radicalaire contrôlée est discutée. La dernière parte de cette thèse concerne l’application du procédé de polymérisation RAFT (polymérisation radicalaire par transfert de chaînes réversible par addition/fragmentation) en iCVD à l’aide de coupons de silicium fonctionnalisés au préalable avec des agents RAFTRecent progress in micro and nanotechnologies require the development of new synthesis process for various material thin films. Polymers, thanks to their properties, are very interesting for fields like microelectronic or biomedical. To respond to this need, many Chemical Vapor Deposition (CVD) technologies are studied. This work focuses on a new method called initied Chemical Vapor Deposition (iCVD). This deposition method gives many advantages as its soft operational conditions (solvent free, low temperature), versatility and conformity. In order to improve the understanding of synthesis mechanism in iCVD, the first part of this work is about the poly(methacrylates) thin films growth kinetic. The study reveals two-regime growth kinetics. A model for the growth mechanism based on the microscopic and macroscopic analysis of thin layers from the two regimes is proposed. The first regime, at the early stage of the growth, is characterized by a slow deposition rate and polymers with low molecular mass. When the second regime appears, the deposition rate is higher and constant and polymers have higher molecular mass. These evolutions could to be explain by the growth film ability to stock monomers and thus increase the local monomer concentration. Poly(methacryaltes) growth kinetics are also investigated on polymeric and porous organosilicate layers. It appears than iCVD is a deposition method that can fill nanometrics pores with polymer really quickly. Moreover, to have a better control on polymer synthesized by iCVD (molecular weight, macromolecular architecture), the possibility to used a Reversible-Deactivation Radical Polymerization (RDRP) method with iCVD process is discussed. The last part of this work concerns the use of Reversible Addition Fragmentation chain Transfer (RAFT) polymerization with the iCVD process thanks to silicon samples pre-functionalized with RAFT agent
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Styan, Katie Graduate School of Biomedical Engineering Faculty of Engineering UNSW. "Polyurethane organosilicate nanocomposites for novel use as biomaterials." Awarded by:University of New South Wales. Graduate School of Biomedical Engineering, 2006. http://handle.unsw.edu.au/1959.4/25218.
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Polymer organosilicate nanocomposites have attracted significant attention over the last decade due to improved mechanical, thermal, and barrier properties. Several nanocomposite researchers have recognised potential for biomedical applications, however none have conducted biological investigations. In this project, the predicted ability of the organosilicate to enhance biostability, modulate the release of included drugs, and confer biofunctionality and control over the host response, were assessed as the three primary hypotheses. The studies were conducted with the objective being employment as urinary device biomaterials. Of prime importance was that no detrimental change in cytocompatibility was resultant. Biomedical thermoplastic elastomeric polyurethane organosilicate nanocomposites were prepared from poly(ether)urethane of 1000g/mol poly(tetramethylene oxide) polyol, 4,4??? diphenylmethane diisocyanate, and 1,4 butanediol chain extender chemistry, and various organosilicates with loadings from 1w% to 15w%, using a solution casting technique. Initially, partially exfoliated nanocomposites were produced using a commercially available organosilicate, Cloisite?? 30B. These nanocomposites displayed several advantageous properties, namely i) significant anti-bacterial activity, reducing S. epidermidis adherence after 24h to ~20% for a 15w% organosilicate loading, ii) enhanced biostability, with a 15w% organosilicate loading displaying only slight degradation after a 6 week subcutaneous in vivo ovine implantation, and iii) static modulation of model drug release as a factor of drug properties and organosilicate loading. The former was attributed to the Cloisite?? 30B quaternary ammonium compound, while the latter two were likely primarily barrier effect related and due to changes to poly(ether)urethane permeability. Electrostatic and chemical interactivity between drug and organosilicate was also implicated in the observed drug release modulation. Unfortunately, a lack of in vitro cytocompatibility and poor in vivo inflammatory response will limit in vivo use. Utilising bioinert 1-aminoundecanoic acid as an alternative organic modification, cytocompatible intercalated nanocomposites were produced thus likely allowing in vivo nanocomposite use and exploitation of the barrier effect related properties. However, these nanocomposites were not antibacterial. Variation of the organic modification and/or use of co-modification were viable means of modulating host response and biofunctionality, however nanoscale dispersion of co-modified silicate was poor. Use of nanocomposite technology was concluded beneficial to existing biomaterials, and specifically to biomaterial application as urinary catheters / stents.
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Martinez, Nelson Yohan Reidy Richard F. "Wettability of silicon, silicon dioxide, and organosilicate glass." [Denton, Tex.] : University of North Texas, 2009. http://digital.library.unt.edu/ark:/67531/metadc12161.
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Miura, Katsukiyo. "Studies on New Radical Reactions of Organosilicon Compounds." Kyoto University, 1993. http://hdl.handle.net/2433/168868.
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本文データは平成22年度国立国会図書館の学位論文(博士)のデジタル化実施により作成された画像ファイルを基にpdf変換したものであるKyoto University (京都大学)
0048
新制・課程博士
博士(工学)
甲第5393号
工博第1284号
新制||工||902(附属図書館)
UT51-93-F150
京都大学大学院工学研究科工業化学専攻
(主査)教授 内本 喜一朗, 教授 高谷 秀正, 教授 伊藤 嘉彦
学位規則第4条第1項該当
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Lourenço, Mirtha Alejandra de Oliveira. "Tuning functionalized periodic mesoporous organosilicas for CO2/CH." Doctoral thesis, Universidade de Aveiro, 2016. http://hdl.handle.net/10773/21817.
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Doutoramento em Ciência e Engenharia de MateriaisEsta tese de doutoramento teve como principal objetivo a conceção de novas organossílicas mesoporosas periódicas (PMOs) para aplicação na separação de misturas gasosas de dióxido de carbono e metano. Materiais PMOs, com grupos fenileno e bifenileno bissililados, foram modificados por introdução de grupos funcionais amina, utilizando uma das seguintes metodologias: i) reação de co-condensação; ii) pós-modificação da ponte orgânica; iii) "grafting". O tamanho dos poros das PMOs funcionalizadas e não funcionalizadas foi definido pelo tamanho da cadeia alquilada da molécula molde (surfactante) utilizada na síntese do material poroso. Estudou-se o efeito do diâmetro dos poros na separação de CO2/CH4. Investigou-se também estratégias alternativas para modificar as propriedades físico-químicas dos materiais através de reações de superfície utilizando irradiação de micro-ondas; deposição de camada atómica (ALD) de óxido de alumínio; e carbonização dos materiais em atmosfera inerte. A investigação experimental foi efectuada em paralelo com estudos computacionais. Realizou-se um estudo de simulação molecular recorrendo ao método de DFT, e usando um arranjo regular de grupos fenileno-sílica, para determinar as características ideais dos materiais para promover a separação de metano do dióxido de carbono em misturas destes gases. Foi utilizado um modelo simples, obtido pela repetição de uma célula unitária com 3 anéis fenileno, para simular a parede dos materiais PMOs e desta forma selecionar e avaliar as interações entre os gases e os grupos funcionais presentes na superfície dos materiais. A tendência do rácio entre energias de interação entre a estrutura da parede do fenileno - PMO e as moléculas de CO2 e de CH4 foi concordante com os rácios das constantes de Henry obtidos pela técnica de adsorção. Demonstrou-se uma boa sinergia entre tarefas experimentais e computacionais, o que permite a otimização de recursos, evitando a síntese desnecessária de materiais que se antecipem serem pouco eficazes para o processo de separação de misturas gasosas CO2 e CH4. Assim, a abordagem seguida nesta tese para alcançar adsorventes eficazes foi baseada numa conjugação interdisciplinar envolvendo troca de informação entre as tarefas de síntese, modelação computacional e adsorção.
The main objective of this PhD Thesis was the design of periodic mesoporous organosilicas (PMOs) for applications in carbon dioxide and methane separation. Novel PMOs were prepared by the modification of phenylene and biphenylene PMO materials with different amine functionalities through one of the three following synthetic strategies: i) co-condensation reaction; ii) organic bridge post-modification; or/and iii) grafting. The pore size of both functionalized and non-functionalized phenylene PMOs was regulated by the size of the alkyl-chain in the surfactant template. Materials with different pore sizes were used to understand the influence of the pore diameter on the CO2/CH4 separation. Additionally, it was aimed to explore alternative strategies to modify the physical-chemical properties of the materials such as microwave-assisted functionalization; atomic layer deposition (ALD) of aluminum oxide at the PMO surfaces; and carbonization of the PMO materials. The experimental research was performed in parallel with computational studies. A molecular simulation study, using the DFT method and a regular arrangement of phenylene-silica groups, of the ideal characteristics of the adsorbent materials, for CO2/CH4 separation was performed. It was used a simple model of the wall of the PMO materials obtained by the repetition of a unit cell with 3 phenylene rings, to select and evaluate interactions between gases and functional groups in the surface of the materials. The tendency between the ratio of the interaction energies between the wall structure of the phenylene-PMO and the CO2 and CH4 molecules was in good agreement with the ratio of the Henry constants achieved by the adsorption technique. Therefore, a good synergy between experimental and computational tasks was implemented to optimize the resources, avoiding the synthesis of ineffective materials. Thus, the strategy of this PhD Thesis to achieve effective adsorbents was based on an interdisciplinary approach and on the ability to link and interchange information between synthetic, computer modeling and adsorption experiments
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Martinez, Nelson. "Wettability of Silicon, Silicon Dioxide, and Organosilicate Glass." Thesis, University of North Texas, 2009. https://digital.library.unt.edu/ark:/67531/metadc12161/.
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Wetting of a substance has been widely investigated since it has many applications to many different fields. Wetting principles can be applied to better select cleans for front end of line (FEOL) and back end of line (BEOL) cleaning processes. These principles can also be used to help determine processes that best repel water from a semiconductor device. It is known that the value of the dielectric constant in an insulator increases when water is absorbed. These contact angle experiments will determine which processes can eliminate water absorption. Wetting is measured by the contact angle between a solid and a liquid. It is known that roughness plays a crucial role on the wetting of a substance. Different surface groups also affect the wetting of a surface. In this work, it was investigated how wetting was affected by different solid surfaces with different chemistries and different roughness. Four different materials were used: silicon; thermally grown silicon dioxide on silicon; chemically vapor deposited (CVD) silicon dioxide on silicon made from tetraethyl orthosilicate (TEOS); and organosilicate glass (OSG) on silicon. The contact angle of each of the samples was measured using a goniometer. The roughness of the samples was measured by atomic force microscopy (AFM). The chemistry of each of the samples were characterized by using X-ray photoelectron spectroscopy (XPS) and grazing angle total attenuated total reflection Fourier transform infrared spectroscopy (FTIR/GATR). Also, the contact angle was measured at the micro scale by using an environmental scanning electron microscope (ESEM).
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PAN, GUIRONG. "MORPHOLOGY AND PROPERTIES OF ANTI-CORROSION ORGANOSILANE FILMS." University of Cincinnati / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1152291690.
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Fukushima, Motoo. "Synthesis and Electrical Conductive Properties of Organosilicon Polymers." Kyoto University, 1999. http://hdl.handle.net/2433/182375.
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Ayoko, G. A. "Mechanistic studies on some sterically hindered organosilicon compounds." Thesis, University of Sussex, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.370428.
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Najim, S. T. "Mechanistic studies on some sterically hindered organosilicon compounds." Thesis, University of Sussex, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.373132.
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De, Witt Joanna Christine. "Switching the reflection in chiral nematic mesoporous silica and organosilica films." Thesis, University of British Columbia, 2012. http://hdl.handle.net/2429/43781.
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Simon, Tamás [Verfasser], and Michael [Akademischer Betreuer] Fröba. "Periodisch Mesoporöse Organosilica - Mit speziellen Morphologien - / Tamás Simon ; Betreuer: Michael Fröba." Hamburg : Staats- und Universitätsbibliothek Hamburg, 2019. http://d-nb.info/1186891874/34.
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Chreim, Yamama. "Synthèse de polymères organosilicies par polycondensation de diènes polycycliques." Grenoble 2 : ANRT, 1986. http://catalogue.bnf.fr/ark:/12148/cb37596742c.
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Moudgil, Suniti 1976. "Organosilicate nanoparticles as gene delivery vehicles for bone cells." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/28307.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 2004.Includes bibliographical references.
(cont.) proliferation. The metabolic response of these cells after particle ingestion was also characterized in order to ensure that the osteoblasts retained their phenotype. The expression of various proteins involved in bone formation, such as alkaline phosphatase, osteocalcin, osteopontin and fibronectin was quantified. The results indicated that osteoblasts retained their phenotype after organosilicate nanoparticle ingestion. The levels of various cytokines expressed during inflammatory response remained low due to the biocompatibility of amorphous silica. An optimized Ca-SiO₂ nanoparticulate system was developed with maximum particle uptake that enhanced cell viability. A model gene delivery system was created by complexing these nanoparticles with plasmid DNA that encoded for green fluorescent protein (GFP). The effects of nanoparticle size, composition and surface charge on complex size, DNA binding affinity and subsequent GFP expression in osteoblasts were investigated in detail. In addition to primary and immortalized osteoblasts, we have studied the effect of this gene delivery system on two other control cell lines: fibroblasts (connective tissue cells) and hepatocytes (non-connective tissue cells). The Ca-SiO₂-DNA complexes displayed significantly higher transfection efficiencies in osteoblasts and fibroblasts relative to hepatocytes compared to lipofectamine-DNA complexes. In addition, Ca-SiO₂-DNA complexes enhanced osteoblast cell proliferation while achieving successful transfection ...
While bone has a substantial capacity to heal itself, there are approximately 1 million fractures that occur in the U.S. annually that are difficult to heal. These include fractures that occur at sites of low vascularity, fractures that result in a large amount of tissue loss, and fractures that result from bone fragility syndromes such as osteoporosis. There has been a great deal of interest in the tissue engineering of bone in order to treat such fractures. One major aspect of the tissue engineering approach involves the addition of growth factors or proteins to synthetic grafts to accelerate bone regeneration. However, delivering these proteins at the appropriate times and therapeutic levels poses significant challenges. Alternatively, delivering the genes that encode for these proteins could offer a more effective treatment, since proper incorporation of the appropriate genes into cellular nuclei would allow the cells to manufacture authentic protein products. The motivation of this research was to design new materials for gene delivery to bone cells. Conventional non-viral vectors are plagued by toxicity and low transfection efficiencies. The purpose of this work was to design bioactive nanoparticles that could enter the osteoblast membrane without inducing toxicity. These materials were silicate-based, since doped silicates have been shown to possess osteogenic properties. A method to synthesize monodisperse, spherical organosilicate nanoparticles using a surfactant-stabilized sol-gel technique was developed. Surface dopants such as Ca, Mg and Na were found to influence cellular response to nanoparticles. In addition to particle composition, particle size was also found to have a significant effect on osteoblast uptake and cell
by Suniti Moudgil.
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Cave, Nigel Graeme. "The adsorption and adhesion of long-chained organosilicon primers." Thesis, Imperial College London, 1990. http://hdl.handle.net/10044/1/47795.
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Chreim, Yamama. "Synthese de polymeres organosilicies par polycondensation de dienes polycycliques." Université Louis Pasteur (Strasbourg) (1971-2008), 1986. http://www.theses.fr/1986STR13134.
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Polycondensation de molecules diinsaturees, mono- ou polycycliques avec des molecules disilylees (hydrosilylation des doubles liaisons par des fonctions si-h. Les polymeres ont des masses moleculaires comprises entre 3000 et 25000. Stabilite thermique jusqu'a 450**(o)c
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Choi, Sung-Hwan. "Dewetting of Polystyrene Thin Films on Organosilane Modified Surfaces." University of Akron / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=akron1145295240.
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Vassilaras, Plousia E. "Alternative Synthetic Methodologies for the Synthesis of Organosilicon Compounds." Case Western Reserve University School of Graduate Studies / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=case1310150433.
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Wang, Yimin. "Pretreatment, Morphology and Properties of Organosilane Anti-Corrison Coatings." University of Cincinnati / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1186412600.
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Ide, Andreas Hans Peter. "Self-Structuring of functionalized micro- and mesoporous organosilicas using boron-silane-precursors." Phd thesis, Universität Potsdam, 2008. http://opus.kobv.de/ubp/volltexte/2008/2371/.
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The structuring of porous silica materials at the nanometer scale and their surface functionalization are important issues of current materials research. Many innovations in chromatography, catalysis and electronic devices benefit from this knowledge.
The work at hand is dedicated to the targeted design of functional organosilica materials. In this context a new precursor concept based on boron-silanes is presented. These precursors combine the properties of a structure directing group and a silica source by covalent borane linkage. Formation of the precursor is easily realized by a sequential two-step hydroboration, firstly on bis(triethoxysilyl)ethene, and secondly on an unsaturated structure directing moiety such as alkenes or polymers. The so prepared precursors self-organize when hydrolysis of their inorganic moiety takes place via an aggregation of their organic side chains into hydrophobic domains. In this way, the additional use of a surfactant as a template is not necessary. Chemical cleavage of these moieties (e.g. by ammonolysis or oxidative saponification) yields an organosilica where all functionalities are exclusively located at the pore wall and therefore accessible. The accessibility of the functionalities is a vital point for applications and is not necessarily granted for common silica functionalization approaches. Further advantages of the boron-silane concept are the possibility to introduce a variety of surface functionalities by heterolytic cleavage of the boron linker and the control of the pore morphology. For that purpose the covalent linkage of different alkyl groups and polymers was studied. Another aspect is the access to chiral boron silane precursors yielding functionalized mesoporous organosilica with chiral functionalities exclusively located at the pore walls after condensation and removal of the structure directing moiety. These materials possess great potential for applications documented by preliminary investigations on chiral resolution of a racemic mixture by HPLC and asymmetric catalysis.
In the course of this work valuable insights into the targeted structuring and surface functionalization of organosilicas were gained. A promising outlook for further investigations is the extension of this concept by altering the structure directing moieties of the precursor. That way the morphology of the final organosilica might be controlled by for example mesogens. Furthermore, the use of the boron linker enables the introduction of multiple functionalities into organosilicas, making the obtained material unique in its performance.Die Nanostrukturierung von funktionalisierten porösen Materialien auf Silikatbasis steht im Brennpunkt der aktuellen Forschung. Anwendungen wie Chromatographie, Katalyse oder die Herstellung elektronischer Bauteile profitieren von den Erkenntnissen, die auf diesem Gebiet gewonnen werden. Die vorliegende Arbeit soll einen Beitrag zur gezielten Herstellung dieser Funktions-materialien leisten. Hierfür wurde ein neues Precursor-Konzept auf der Basis von Borsilanen vorgestellt. Diese Precursoren werden über eine sequentielle zweistufige Hydroborierung an Bis(triethoxysilyl)ethene und ein Alken oder ein ungesättigtes Polymer erhalten. Über den zweiten Schritt wird hierbei die so genannte strukturgebende Gruppe eingeführt und damit das Template kovalent gebunden. Dadurch entfällt im Vergleich zum bekannten Nanocasting-Mechanismus zum einen die Verwendung des herkömmlichen Templates für die Bildung der Porenstruktur und zusätzlich führt die Mikrophasenseparation während der Kondensation zu einer Anordnung der strukturgebenden Gruppen des Precursors an der Silikatphasengrenze. Nach der chemischen Abspaltung dieser Gruppen, die gleichzeitig zur Einführung funktioneller Gruppen führt, werden somit hochporöse Organosilikate erhalten, in denen sich die funktionellen Gruppen ausschließlich an der Porenoberfläche befinden. Ein Vorteil der Verwendung der Hydroborieung wird in der Vielfalt der funktionellen Gruppen deutlich, die eingeführt werden können. Die Zugänglichkeit der funktionellen Gruppen ist entscheidend für potentielle Anwendungen und bei herkömmlichen Organosilikaten nicht zwangsläufig gegeben. Ein herausragender Aspekt dieses Konzepts besteht in der Möglichkeit, sehr einfach chirale Precursoren und damit Organosilikate mit hoch funktionalisierten, chiralen Oberflächen herzustellen. Es konnte gezeigt werden, dass sich diese Materialien sowohl für die chromatographische Trennung von Racematen mittels HPLC als auch für die asymmetrische Katalyse eignen. Durch die in dieser Arbeit erhaltenen Ergebnisse konnten wertvolle Erkenntnisse zur Ober-flächenfunktionalisierung und Strukturierung von mesoporösen Silikaten gewonnen werden. Die Möglichkeit, das vorgestellte Konzept auf andere strukturgebende Gruppen wie zum Beispiel Mesogene zu übertragen und damit die Porenmorphologie gezielt zu steuern, eröffnet viele weitere interessante Materialeigenschaften.
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Masangane, Phindile Clemintine. "Some chemistry of sterically hindered tetrasilylmethane derivatives." Thesis, Imperial College London, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.369193.
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