A range of mesoporous materials based on SBA-15, KIT-6 and FDU-12 have been prepared using neutral block copolymers Pluronic P123 and F127 and characterised using methods including electron microscopy and nitrogen adsorption. Typically the materials have a hexagonal (p6mm) or cubic (Fm3m and Ia-3d) symmetry and pore geometry and are rendered porous by either calcination or solvent extraction. Organic functional groups were incorporated into the silica walls of the materials by co-condensation in the form of propyl thiols and additives in the form of alkanes were added to control pore size and geometry. The effects of temperature, additives, organic functionalisation, synthesis time and sol-gel composition were investigated and the resulting materials were tested as supports for protein adsorption, enzyme immobilisation, and drug delivery. Two FDU-12 materials of differing entrance and cavity sizes were used to adsorb a range of proteins with molecular weight 17 to 160 kDa to determine if there was a size exclusion effect. It was seen that the larger pore material was able to adsorb proteins of a larger size (molecular weight 105 kDa) and an exclusion effect was observed when the dimension of the proteins became too great (larger than 130 kDa). There was no clear trend for the smaller pore material where each protein was adsorbed to some extent by the material but apart from the smallest protein, myoglobin, mainly on the surface and not within the pores. The adsorption of the lipase B from Candida Antartica, CALB, was studied on a range of mesoporous supports with their templates removed by either calcination or extraction. The effect of pore size and functionalisation was investigated in terms of maximum loading and rate of loading. By functionalising the KIT-6 material the maximum loading of CALB was reduced from 45.5 to 32 mg/g whereas functionalising the FDU-12 material increased the maximum from 33 to 42.5 mg/g. The activity of the immobilised CALB was measured by enantioselective transesterification of (R)-1-phenylethanol in methyltetrabutyl ether (MTBE). The effect of loading, surface functionalisation and reusability in organic media were investigated. Functionalisation with propyl thiol was seen to increase the rate of conversion after 30 minutes for both KIT-6 and FDU-12 materials. Selected FDU-12 and KIT-6 materials with window sizes from 6 to 12 nm and with and without functionalisation were used to carry out a drug release study using Bovine serum albumin (BSA). BSA was loaded onto the material and the uptake quantified using nitrogen adsorption, elemental analysis, and thermogravimetric analysis. The release of BSA into simulated body fluid at 37 ºC was measured using HPLC. Functionalisation was seen to have little effect. The type of cubic morphology controlled the rate at which the BSA was released. The KIT-6 3D channel material exhibited a burst release initially followed by a steady release of BSA whereas the mesocage FDU-12 material had a slower and more linear release profile, closer to that desired.

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abstract: Nanoporous electrically conducting materials can be prepared with high specific pore volumes and surface areas which make them well-suited for a wide variety of technologies including separation, catalysis and owing to their conductivity, energy related applications like solar cells, batteries and capacitors. General synthetic methods for nanoporous conducting materials that exhibit fine property control as well as facility and efficiency in their implementation continue to be highly sought after. Here, general methods for the synthesis of nanoporous conducting materials and their characterization are presented. Antimony-doped tin oxide (ATO), a transparent conducting oxide (TCO), and nanoporous conducting carbon can be prepared through the step-wise synthesis of interpenetrating inorganic/organic networks using well-established sol-gel methodology. The one-pot method produces an inorganic gel first that encompasses a solution of organic precursors. The surface of the inorganic gel subsequently catalyzes the formation of an organic gel network that interpenetrates throughout the inorganic gel network. These mutually supporting gel networks strengthen one another and allow for the use of evaporative drying methods and heat treatments that would usually destroy the porosity of an unsupported gel network. The composite gel is then selectively treated to either remove the organic network to provide a porous inorganic network, as is the case for antimony-doped tin oxide, or the inorganic network can be removed to generate a porous carbon material. The method exhibits flexibility in that the pore structure of the final porous material can be modified through the variation of the synthetic conditions. Additionally, porous carbons of hierarchical pore size distributions can be prepared by using wet alumina gel as a template dispersion medium and as a template itself. Alumina gels exhibit thixotropy, which is the ability of a solid to be sheared to a liquid state and upon removal of the shear force, return to a solid gel state. Alumina gels were prepared and blended with monomer solutions and sacrificial template particles to produce wet gel composites. These composites could then be treated to remove the alumina and template particles to generate hierarchically porous carbon. / Dissertation/Thesis / Ph.D. Chemistry 2012

La recherche scientifique contemporaine en matière de matériaux est largement orientée autour de l’optimisation et l’élaboration de nouveaux matériaux poly-fontionnels, multi-structurés et aux dimensions réduites. De tels matériaux conduisent à s’intéresser à la problématique des comportements spécifiques résultant des différentes interfaces mises en jeu ; il peut s’agir d’interfaces physiques entre différents milieux (états différents, compositions chimiques différentes …) ou des interfaces entre différentes propriétés. Dans ce contexte, nous nous sommes intéressés aux corrélations pouvant exister entre les propriétés de luminescence et la réactivité de surface de films mésoporeux d’oxyde métalliques dopés avec des ions EuIII. Ces deux propriétés étant fortement dépendantes de la structure des matériaux, une grande partie de notre travail a été dédiée à la caractérisation de cette dernière. Un intérêt particulier a été porté à l’étude des conséquences de la présence des ions EuIII et à la localisation de ces derniers au sein des matrices étudiées. Finalement, il est apparu que la luminescence des ions EuIII au sein des films mésoporeux à base de TiO2 peut permettre de suivre les réactions redox se produisant au sein des pores, comme par exemple la photo-dégradation de composés organiques ou la photo-réduction de sels métalliques. La photo-réduction in situ permet la formation de réseaux périodiques de nanoparticules métalliques. Ces matériaux offrent donc de nombreuses perspectives d’applications dans des domaines aussi variés que les télécommunications optiques, la photonique, la photocatalyse… / Materials contemporary scientific research is largely devoted to the optimization and the elaboration of new poly-functional, multi-structured and size-reduced materials. Then, specific behaviors due to the different interfacial aspects of those materials – physical interfaces between different matter states, different chemical phases… or properties interfaces – have become a major issue requiring further investigations. In this context, our work deals with correlations that could be established between luminescence properties and surface reactivity of EuIII-doped metal oxide mesoporous thin films. As properties can be linked to materials structure, an important part of our work has been dedicated to structural characterization. EuIII ions incorporation specific effects and ions location within film walls have been particularly studied. Finally, it appeared that EuIII ions luminescence could provide a mean to follow redox reactions occurring within pores, such as organic compounds photo-degradation or metallic salts photo-reduction. In situ photo-reduction can lead to periodic arrays of metallic nanoparticles. La photo-réduction in situ permet la formation de réseaux périodiques de nanoparticules métalliques. Those materials can open up the way in many applications such as optical telecommunication, photonics, photocatalysis…

Orientador: Sidney José Lima Ribeiro / Orientador: Marc Verelst / Banca: Younès Messaddeq / Banca: Oscar Manoel Loureiro Malta / Banca: Luis Antonio Ferreira Martins Dias Carlos / Banca: Marie-Joëlle Menu / Banca: Jeannette Dexpert-Ghys / Resumo: Partículas esféricas de sílica mesoporosa foram obtidas a partir da síntese "template" pelo processo de pirólise de aerossol. O processo foi otimizado para a obtenção de materiais mesoporosos sem resíduos orgânicos e preparados em uma única etapa, eliminando assim, a longa etapa de remoção do surfactante na metodologia tradicional (tratamento térmico ou extração soxhlet, podendo durar dezenas de horas). A otimização do processo de pirólise de aerossol proposta nesta tese reduziu este tempo para apenas alguns minutos. Os materiais apresentaram uma área superficial (BET) de até 1028 m2 .g-1 , com volume de poros (BJH) de 0,58 cm3 .g-1 . Os difratogramas de raios-X indicaram um alto grau de organização com um arranjo hexagonal de poros, confirmado também pela microscopia eletrônica de transmissão. Além disto, bandas características de grupos orgânicos não foram observadas nos espectros de absorção na região do infra-vermelho para as amostras obtidas acima de 600ºC. Amostras dopadas com íons Eu3+ também foram preparadas durante a tese. A análise por espectroscopia de luminescência, para íons Eu3+ , indicou que o íon está encapsulado nos canais mesoporosos sem prévia modificação química da matriz. Posteriormente, moléculas de 1,10- Fenantrolina foram coordenadas ao íon Eu3+ aumentando a faixa espectral de excitação do íon (efeito antena). Além disto, partículas luminescentes também foram obtidas pela incorporação do complexo Eu(fod)3 ou rodamina-B nos poros das matrizes. Finalmente, testes de recobrimento (core shell, SiO2 mesoporoso-SiO2) das partículas luminescentes foram realizados e os resultados indicaram que independentemente da espessura obtida pelo processo de recobrimento, o grau de organização dos poros e a fotoluminescência não sofreram alterações / Abstract: Spherical mesoporous silica particles were obtained using the template synthesis by spray pyrolysis process. The process was optimized for the preparation of the mesoporous materials in one-pot route without organic residues, eliminating thus, the long process of removal of the surfactant, usually used in the available methods (heat treatment or soxhlet extraction, which require several hours or days). The one- pot route proposed in this thesis reduced the extraction process to only a several minutes. These materials presented a surface area value (BET) of 1028m2 .g-1 and pore volume (BJH) was 0,58 cm3 .g-1 . The X-ray diffraction patterns and the transmission electronic micrographs show an ordered typical p6mm 2D hexagonal mesostructure. Characteristics bands of organic groups were not observed in the infra-red absorption spectra for the samples obtained at 600ºC. Moreover, SiO2 mesoporous doped with Eu3+ ions were also prepared. Luminescence data suggest that the Eu3+ ions were successful encapsulated into the channels of mesoporous silica without any preliminary chemical modification of the matrix. Moreover, extra ligands such as 1,10-Phenantroline can be further coordinated, increasing the spectral range excitation (antenna effect). Furthermore, luminescent particles were also prepared by the wet impregnation of Eu(fod)3 complex and rhodamine-B molecules. Finally, tests of coating (core shell, SiO2 mesoporous-SiO2) of luminescent particles had been carried through and the The results obtained show spherical shape and the observation of a highly ordered hexagonal array of mesochannels further confirms the 2D hexagonal p6m structure. Luminescence results reveal that rhodamine-B has been successfully encapsulated into the channels of mesoporous particles. Silica coating has been observed in TEM measurements / Doutor

Conselho Nacional de Desenvolvimento Científico e Tecnológico / The mesoporous materials like MCM-41apresentam hexagonal arrangement of mesopores with pore diameter from 2 to 10 nm and high surface area. Due to these characteristics, these materials are considered promising as support for heterogeneous catalysts, devices for controlled drug release and absorption. In this work, were synthesized mesoporous materials like MCM-41 via two synthesis routes in order to correlate the synthetic route to the surface area, assess their influence on the structural and morphological properties, and their respective application as dye adsorbent textiles. For both synthesis routes were used as precursors of silica gel, sodium silicate, water and cetyltrimethylammonium chloride (CTMABr), as an agent-driver structure. In the first synthesis route the materials were obtained by hydrothermal method with different temperatures (ambient 70 ° C and 100 ° C) and aging times (2h, 2 4h, 48h and 72h), with pH adjustment and every 24 hours calcinations at 550 ° C/4h. In the second synthesis route, we adopted the aging temperature environment and different times of crystallization (, 24h, 48h and 72h), no pH adjustment of the reaction medium and calcinations was performed at 550 ° C/6h. The MCM-41 was analyzed by X-ray diffraction (XRD), thermogravimetric analysis (TG, DTA and DTG), and absorption spectroscopy in the infrared (IR) and nitrogen adsorption (BET method - Brunauer-Emmett-Teller). Through the analysis of XRD, TG, IR and nitrogen adsorption showed that the calcination conditions were promising agent for the removal of driver structure and the optimization of routes allowed for the synthesis of MCM-41 with a shorter time and temperature aging, expected in the literature. However, it was not possible to establish a relationship between time, temperature and aging structural ordering of MCM-41. In addition, the test results of the use of MCM-41 as an adsorbent textile dye showed a higher adsorption of the dye Orange-16, for not calcined sample as compared to calcined sample at room temperature, confirming the promising application in the treatment of waste textiles. / Os materiais Mesoporosos do tipo MCM-41apresentam arranjo hexagonal de Mesoporoso com diâmetro de poro entre 2 a 10 nm e elevada área superficial. Devido a essas características, estes materiais são considerados promissores como suporte para catalisadores heterogêneos, dispositivos pra liberação controlada de fármacos e adsorção. Neste trabalho, foram sintetizados os materiais Mesoporosos do tipo MCM-41 através de duas rotas de síntese com o objetivo de correlacionar à rota sintética com a área superficial, avaliar sua influência sobre as propriedades estruturais e morfológicas, e sua respectiva aplicação como adsorvente de corante têxtil. Para as duas rotas de síntese utilizaram- se como precursores a sílica gel, silicato de sódio, água e o cloreto de cetiltrimetilamônio (CTMABr), como agente direcionador de estrutura. Na primeira rota de síntese os materiais foram obtidos através do método hidrotérmico, com diferentes temperaturas (ambiente, 70°C e 100°C) e tempos de envelhecimento (2h, 24h, 48h e 72h), com ajuste de pH a cada 24h e calcinação a 550°C/4h. Na segunda rota de síntese, adotou-se a temperatura de envelhecimento ambiente e diferentes tempos de cristalização (, 24h, 48h e 72h), não houve ajuste do pH do meio reacional e a calcinação foi realizada a 550°C/6h. Os MCM-41 obtidos foram analisados por difração de raios-X (DRX), análise termogravimétrica (TG, DTA e DTG), espectroscopia de absorção na região do infravermelho (IV) e adsorção de nitrogênio (método BET Brunauer- Emmett-Teller). Através das analises de DRX, TG, IV e adsorção de nitrogênio verificou-se que as condições de calcinação foram promissoras para a remoção do agente direcionador de estrutura e que a otimização das rotas possibilitou a síntese de MCM- 41 com um menor tempo e temperatura de envelhecimento, que o previsto na literatura. Entretanto, não foi possível estabelecer uma relação entre o tempo, temperatura de envelhecimento e ordenação estruturald do MCM-41. Além disso, os resultados dos ensaios da utilização do MCM-41 como adsorvente de corante têxtil mostraram uma elevada adsorção do corante Orange-16, para amostra não calcinada quando comparada a amostra calcinada, a temperatura ambiente, confirmando a promissora aplicação no tratamento de resíduos têxteis.

Dans ce travail, les propriétés des oxydes de titane mésoporeux organisés ont été étudiées en détail. La synthèse de ces matériaux a été mise au point auparavant au laboratoire à l’aide d’une méthode combinant le mécanisme transcriptif à partir des cristaux liquides du copolymère bloc P123 et la méthode EISA. Tout d’abord, une optimisation des conditions d’élimination du tensioactif a été effectuée en testant des méthodes d’extraction à partir de solvant et des méthodes thermiques. L’élimination du P123 par l’eau suivie d’un rinçage à l’acétone est efficace, simple et rapide et en même temps favorise la formation de la phase anatase du TiO2. Par contre, les propriétés photocatalytiques de ces TiO2 extraits à l’eau sont médiocres et ne sont améliorées qu’après calcination. En combinant une extraction du P123 à l’eau avec une calcination les oxydes de titane mésoporeux possédent une meilleure activité photocatalytique que celle de l’anatase commercial. Dans un second temps l’incorporation du zinc et du tungstène dans les TiO2 mésoporeux organisés a été investie dans le but d’améliorer leur activité photocatalytique. L’introduction de faibles quantités de zinc (<10% mol) augmente la surface spécifique ; au-delà la mésostructuration est perdue. L’incorporation du tungstène dans le TiO2 mésoporeux n’a pas d’influence sur l’organisation des mésopores, mais des agrégats de WO3 orthorhombique coexistent avec le réseau mésoporeux de TiO2 anatase. Même si la présence d’oxyde de zinc ou de tungstène dans la matrice TiO2 mésoporeux diminue bien l’énergie bandgap, l’activité photocatalytique ne s’en trouve pas améliorée. D’autre part, la synthèse de matériaux à porosité bimodale, en utilisant deux systèmes mixtes de tensioactifs hydrogéné/fluoré, CTABr/RF8(EO)9 et P123/ RF8(EO)9, a été explorée. Sur la base des diagrammes de phase de ces deux systèmes dans l’eau, les solutions micellaires et les cristaux liquides ont été investis pour préparer des silices mésoporeuses en utilisant les deux mécanismes CTM et LCT. Quand le CTABr est présent une seule taille de pores dans le domaine mésoporeux est observée, toutefois il est possible qu’une bimodalité de type micro-mésopores existe. Par contre, l’utilisation de la phase hexagonale du système P123/RF8(EO)9 permet d’obtenir des matériaux à deux tailles de pores distincts dans le domaine mésoporeux. / In this work we will study in detail the properties of the mesoporous TiO2 materials, for which the preparation was developed previously via a method combining Liquid Crystal Templating (LCT) and EISA mechanisms, using P123 as template. We have tested, in the first time, extraction and thermal methods efficiency to eliminate surfactant in order to optimize the P123 elimination step. Removal of P123 using water followed by washing with acetone is effective, easy and promotes the formation of the anatase phase of TiO2. Otherwise, the photocatalytic properties of the obtained TiO2 are not important and can be improved after calcination. Combining extraction using water and calcination give rise to mesoporous TiO2 with better photocatalytic activity than that of commercial anatase. The incorporation of zinc and tungsten in the mesoporous well-ordered TiO2 has been investigated in the third time, in order to improve their photocatalytic activity. The introduction of small amounts of zinc (<10 mol%) increases the surface area; beyond this amount the mesostructure is lost. The incorporation of tungsten in the mesoporous TiO2 does not affect the mesopores organization, and orthorhombic WO3 aggregates are formed beside the mesoporous network of anatase TiO2. Although, the presence of zinc or tungsten oxides in the matrix decreases the bandgap of mesoporous TiO2, the photocatalytic activity is not improved. In the third time, the synthesis of bimodal porosity materials, using a mixed surfactant systems hydrogenated/fluorinated, CTABr/RF8(EO)9 and P123/RF8(EO)9, was explored. Based on the phase diagrams of these two systems in water, micellar solutions and liquid crystals have been investigated to prepare mesoporous silicas using two mechanisms CTM and LCT. When CTABr is present, pores of one size in the mesoporous range are observed, however, it is possible that bimodal type micro-mesopores exist. The use of the hexagonal liquid crystal phase of P123/RF8(EO)9 provides two separate pore sizes materials in the mesoporous range.

Abstract: Superacidic mesoporous silica materials containing embedded heteropolyacids (HPAs) were synthesized by sol–gel method in acidic media. In these materials, HPAs were immobilized into the silica structure covalently. The most acidic materials were obtained at the use of Pluronic P123 as a non-ionic pore-forming agent. Ionic surfactants also formed mesoporous structures, however, their interaction with HPA reduced acidity of the products. Obtained materials were tested as heterogeneous catalysts in liquid-phase alkylation of 1,3,5-trimethylbenzene by 1-decene. The most effective catalyst demonstrated higher conversion of starting substances to long-chain isomeric alkylbenzenes as compared to the activity of zeolite HY, a well-known alkylation catalyst. No leaching of HPA from silica gel was observed after the alkylation.

The adsorption of cytochrome c onto mesoporous silica (MCM-41) was investigated in this study. MCM-41 was synthesized and characterized by different methods. The pore size of MCM-41 was calculated from each method and all were in agreement with each other. Result from SAXS method showed a well ordered 2D hexagonal structure of MCM- 41. To investigate the effect of pH on adsorption process, different buffers were used with various pH in the range from 3.8 to 10.7. It was observed that the maximum adsorption occurs at pH near the isoelectric point of cytochrome c. The surface charges of cytochrome c and MCM-41 play an essential role for the process of adsorption. Desorption of cytochrome c from MCM-41 was investigated as well. Pure water and buffers with pH 7.1 and 10.7 were used to study the desorption. The result shows that desorption of cytochrome c from MCM-41 takes place at a pH above its isoelectric point.