Submitted by CAMILA RAIANE FERREIRA null (camilaraiane@yahoo.com.br) on 2017-03-19T18:30:27Z No. of bitstreams: 1 Dissertação Camila Raiane Ferreira.pdf: 4377066 bytes, checksum: 851413696be408fc889a5876618e8a66 (MD5) / Approved for entry into archive by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br) on 2017-03-23T17:40:49Z (GMT) No. of bitstreams: 1 ferreira_cr_me_araiq_par.pdf: 1225248 bytes, checksum: 99ced116194746db03b9acc48348a1ff (MD5) / Made available in DSpace on 2017-03-23T17:40:49Z (GMT). No. of bitstreams: 1 ferreira_cr_me_araiq_par.pdf: 1225248 bytes, checksum: 99ced116194746db03b9acc48348a1ff (MD5) Previous issue date: 2017-02-20 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O desafio da produção e aplicação de nanocompósitos poliméricos vêm recebendo grande destaque científico devido ao seu caráter multifuncional. Os materiais híbridos orgânico-inorgânicos apresentam propriedades distintas que não se limitam à soma das propriedades de seus componentes separadamente, mas decorre de um sinergismo entre as fases em nível molecular. Como uma vertente do estudo desses materiais, a modificação de superfícies de argilas minerais se tornou uma forma de melhorar ou criar novas propriedades em materiais híbridos. Um exemplo é o método grafting, que consiste na reação de superfície entre argila e a matriz polimérica. Para tornar compatível a fase orgânica (polímero) e a fase inorgânica (argila) é necessário um agente funcionalizante, no caso, foi usado o TMSM (trimetoxisilil propil metacrilato) ligado a argila por reações com os grupos silanóis/Si-OH. O objetivo é aprimorar a síntese de materiais híbridos orgânico-inorgânicos utilizando o método grafting, sendo a fase orgânica o polímero termoplástico poli(metil metacrilato) (PMMA) e a fase inorgânica será as argilas derivadas da montmorilonita (Cloisite® 15A e Cloisite® 93A) já previamente funcionalizadas com TMSM. A comparação do conjunto de nanocompósitos permitiu analisar a evolução das propriedades térmicas, em como as baixas quantidades de argila em escala nanométrica presentes na matriz polimérica pode influenciar na estabilidade térmica do PMMA. A evolução das propriedades térmicas foi analisada por meio de técnicas experimentais de TG e DSC. Os nanocompósitos foram caracterizados por DRX, FTIR, SAXS, MEV e RMN. O presente trabalho mostrou que há estabilização térmica apenas do TMSM e do percussor argila-TMSM em comparação aos nanocompósitos antes do tratamento térmico. E que com o tratamento térmico dos nanocompósitos há uma maior estabilização em relação ao polímero, onde a argila funciona como uma barreira de difusão dos gases formados na reação de decomposição do polímero. Os dados de caracterização mostram que a funcionalização ocorreu de maneira eficaz. Uma análise das propriedades ópticas e elétricas da argila montmorilonita foi feita por cálculos teóricos baseado na Teoria do Funcional da Densidade (DFT). Os resultados mostraram a influência do Fe2+ no band gap do material e consequentemente uma menor tendência isolante da argila. / The challenge of the production and application of polymer nanocomposites has been receiving great scientific attention due to its multifunctional character. The organic-inorganic hybrid materials have distinct properties that are not limited to the sum of the properties of their components separately, but derive from a synergism between the phases at the molecular level. As an aspect of the study of these materials, the surface modification of clay minerals has become a way to improve or create new properties in hybrid materials. An example is the grafting method, which consists of the surface reaction between clay and the polymer matrix. In order to make the organic phase (polymer) and the inorganic phase (clay) compatible, a functionalizing agent is required; in this case, the TMSM (trimethoxysilyl propyl methacrylate) bound to clay was used by reactions with the silanols / Si-OH groups. The aim is to improve the synthesis of organic-inorganic hybrid materials using the grafting method, the organic phase being the thermoplastic polymer poly (methyl methacrylate) (PMMA) and the inorganic phase will be clays derived from montmorillonite (Cloisite® 15A and Cloisite® 93A) previously functionalized with TMSM. The comparison of the number of nanocomposites allowed to analyze the evolution of the thermal properties, such as low amounts of clay at the nanoscale present in the polymer matrix can influence the thermal stability of PMMA. The evolution of the thermal properties were analyzed by TGA and DSC experimental techniques. The nanocomposites were characterized by XRD, FTIR, SAXS, SEM and NMR. The present work showed that there is only thermal stabilization of the TMSM and the clay-TMSM precursor in comparison to the nanocomposites before the heat treatment. And after the heat treatment of the nanocomposites there is a greater stability in relation to the polymer, in which the clay acts as a diffusion barrier gas formed in the decomposition reaction of the polymer. The characterization data show that functionalization occurred effectively. An analysis of the optical and electrical properties of montmorillonite clay was made by theoretical calculations based on the Density Functional Theory (DFT). The results showed the influence of Fe2+ on the band gap of the material and consequently a lower insulating tendency of the clay.

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

Depuis quelques décennies, les matériaux composites organique/inorganique font l’objet de nombreux travaux de recherches. En raison de leurs propriétés uniques et intermédiaires entre les deux mondes minérales et organiques, ces matériaux sont d’un grand intérêt pour des nombreuses applications tel que le domaine, d’optique, la microfluidique, la microélectronique…, La synthèse de ce type des matériaux est réalisée à moindre coût en deux étapes : La synthèse du réseau inorganique est effectué par procédé sol-gel , tant qu’à la partie organique des compositions de type résines négatives et positives possède la particularité d’être photo-réticulables sous irradiation (UV et visible). Parallèlement, est apparue la lithographie par écriture laser (spot de quelques microns). Elle s’avère très pertinente pour la mise au point d’un procédé pour lequel des objets de petites dimensions (quelques Microns) et de petites surfaces sont à réaliser car elle permet de s’affranchir de la fabrication de masques. Cette technique associée aux résines négatives, n’est pas idéale pour la fabrication d’objets de grandes surfaces en raison de temps de fabrication induits trop long. Il est, par exemple, extrêmement compliqué et couteux d’utiliser l’écriture Laser pour la réalisation de dispositifs microfluidiques. En effet, la création de canaux de taille micronique nécessite une très grande surface à insoler. Il est donc bien plus pertinent de travailler sur l’association de l’écriture laser avec une résine de type positive. L’objectif principal de ce travail est la synthèse, l’optimisation et mise en œuvre d’un matériau hybride photosensible de type résine positive : Application à la fabrication des capteurs microfluidiques. Notre choix s’est porté sur le poly(amic acid) PAA de masse molaire 2340 g/mol comme partie organique, connu pour ces bonnes propriétés mécaniques et sa grande stabilité thermique. Le travail est centré d’une part, sur la synthèse d’une résine positive photosensible à la longueur d’onde utilisée (365 nm) à base du polymère PAA. En général, les PAA sont très solubles dans une solution alcaline aqueuse, dû à la présence d’acide carboxylique. Afin d’améliorer le contraste entre la partie insolée et non insolée après le développement, un inhibiteur de dissolution 1,3,5-tris[(2-vinyloxy)ethoxy]benzène (TVEB) est greffé au PAA via la fonction vinyl éther. Ce dernier permet la réduction de la teneur en acide carboxylique dans le motif répétitif du polymère et comme conséquence diminuer la dissolution de la partie non insolée. D’autre part, la synthèse du matériau hybride à base de la résine photosensible optimisée, est réalisée par greffage d’un précurseur ORMOSIL le 4-vinyléther-phenyltriéthoxysilane (VEPTES) pré-hydrolysé par procédé sol-gel comme partie inorganique à notre polymère. Afin d'optimiser le matériau, une étude structurale a été réalisée depuis la synthèse du solution jusqu'à l'obtention des dépôts et enfin la création des canaux microfluidiques. Une amélioration significative au niveau des propriétés mécaniques et thermiques est notée au niveau du polymère par ajout d’une partie minérale. / In recent decades, the organic / inorganic composite materials are the subject of many research works. Because of their unique properties and intermediate between inorganic and organic worlds, these materials are of great interest for many applications such as the area, optical, microfluidics, microelectronics ... The synthesis of this type of materials is carried out at a lower cost in two stages: The synthesis of inorganic network is made by sol-gel process, as well as the organic part of the negative and positive resin type compositions has the particularity of being photo-crosslinked under irradiation ( UV and visible).Meanwhile, the lithography by laser writing has appeared (spot a few microns). It is particularly appropriate for the development of a method for which small objects (a few microns) and small surfaces are to achieve because it eliminates the production of masks. This technique associated with negative resins, is not ideal for manufacturing large objects surfaces due to induced production time too long. It is, for example, be extremely complicated and expensive to use writing laser for producing microfluidic devices. Indeed, the creation of micron-sized channels requires a very large surface area to be exposed. It is therefore more appropriate to work on the combination of laser writing with a resin positive type. The main objective of this work is the synthesis, optimization and implementation of a photosensitive hybrid material resin positive type: Application to the fabrication of microfluidic sensors. Our choice fell on the poly(amic acid) PAA with molar mass of 2340 g/mol as an organic part, known for its good mechanical properties and high thermal stability.The work focuses on a part, on the synthesis of a positive photosensitive resin at the wavelength used (365 nm) based on the PAA polymer. In general, PAA are very soluble in an aqueous alkaline solution, due to the presence of carboxylic acid. In order to improve the contrast between the irradiated and unirradiated part after the development, an dissolution inhibitor 1,3,5-tris [(2-vinyloxy) ethoxy] benzene (TVEB) is grafted to the PAA via the vinyl ether function. This allows the reduction of the carboxylic acid content in the repeating unit of the polymer and as a consequence reduces the dissolution of the non-exposed part.On the other part, the synthesis of the hybrid material based on the optimized photosensitive resin is formed by grafting a precursor ORMOSIL 4-vinylether-phenyltriethoxysilane (VEPTES) pre-hydrolyzed by sol-gel method as the inorganic part to our polymer. In order to optimize the material, a structural study was conducted for the synthesis of the solution until the deposits and the creation of microfluidic channels. A significant improvement in mechanical and thermal properties is recorded at the polymer by adding an inorganic portion.

In organic-inorganic hybrid compounds an organic and an inorganic component are combined to form either a coordination or an ionic material. Relevant to the current study are hybrid materials composed of an organic part that contains one or more functional groups, for example amine, amide or carboxylic acid functional groups, and a metal halide inorganic portion. These functional materials display a range of interesting and desired properties, as evidenced from numerous literature reports on their properties. In order to utilise these properties in applications, a detailed understanding of the way that the crystal structure influences the properties of a material is required. However, before this step can be achieved, it is necessary to obtain information on the structural trends of the materials, and to use the approach of crystal engineering to identify robust supramolecular synthons that may afford structural control and prediction. The aim of the current study was to investigate the synthesis and crystal structures of hybrid materials, both ionic and coordination, composed of divalent transition metal halides and the organic components 4-aminobenzoic acid, 4-aminobenzamide and isonicotinic acid, and to identify the structural trends and crystal engineering synthons displayed by these materials. A secondary objective was the preliminary identification of properties exhibited by selected materials, in order to decide on the suitability of the materials for detailed future property investigations. Part of the work describes the investigation of the structural characteristics of coordination materials prepared by the combination of the organic and inorganic components. Five novel crystal structures of coordination materials were determined, and these are compared with six related coordination structures reported in the literature. Two of the novel structures display interesting one-dimensional coordination polymers, one of which has never been reported previously in the literature. The molecular and structural characteristics of both the novel and the literature coordination structures are presented in detail, and this discussion includes a description of the coordination geometry, the molecular geometry, packing trends, hydrogen bonding interactions and aromatic interactions. A comparison study across the three families of organic components in which the structural trends, hydrogen bonding interactions, aromatic interactions, ligand geometry and coordination modes are compared, is included. The results of the synthesis of the coordination materials by means of a mechanochemical method are presented, and the products afforded by this method are compared with those prepared via solution crystallisation. Finally, the results of preliminary studies of the thermal and electronic propertries of the materials are presented and interpreted. The combination of the hybrid components as cations and anions to form ionic materials yielded nine novel structures, and these were compared with five related ionic structures reported in the literature. The novel structures include three polar structures that contain the 4-ammoniumbenzamide cation, and to our knowledge no structures containing this cation have ever been reported in the literature, hence a significant contribution to the structural knowledge of perhalometallate salts of 4-ammoniumbenzamide is made by this study. In addition two novel structures display interesting one-dimensional and two-dimensional polymeric anions, respectively, are reported. The discussion of the novel and literature ionic structures includes a description of the molecular geometry of each of the components, the identification of packing trends, and an analysis of the hydrogen bonding and aromatic interactions occurring in the structures. The structures of all three families of organic components are compared, and trends in structural type, anion geometry, water inclusion, hydrogen bonding and functional group recognition are presented. In addition, a detailed analysis of robust crystal engineering synthons occurring in these structures is presented. Lastly the results of preliminary property investigations of the thermal and electronic properties of the materials are presented and discussed / Dissertation (MSc)--University of Pretoria, 2011. / Chemistry / unrestricted

付記する学位プログラム名: 充実した健康長寿社会を築く総合医療開発リーダー育成プログラム / 京都大学 / 新制・課程博士 / 博士(工学) / 甲第23227号 / 工博第4871号 / 新制||工||1760(附属図書館) / 京都大学大学院工学研究科高分子化学専攻 / (主査)教授 田中 一生, 教授 秋吉 一成, 教授 古賀 毅 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM

京都大学 / 新制・課程博士 / 博士(工学) / 甲第24586号 / 工博第5092号 / 新制||工||1975(附属図書館) / 京都大学大学院工学研究科高分子化学専攻 / (主査)教授 秋吉 一成, 教授 大塚 浩二, 教授 田中 一生 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM

Thesis (MSc (Chemistry and Polymer Science))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: Hybrid graft copolymers of polystyrene (PSty) and polydimethylsiloxane macromonomers (PDMS) were synthesised. PSty-g-PDMS was synthesised employing the grafting through technique via a conventionally free radical polymerization (FRP) using a polydimethylsiloxane macromonomer. In this series the amount of PDMS incorporated into the copolymer was varied by varying the macromonomer to styrene ratios as well as the length of the PDMS side chain. This allows for the study of the effect that the macromonomer content and the branching length has on the efficiency of the grafting process. A second series of PDMS-g-PSty was also synthesized where the PDMS forms the backbone and the PSty the grafts. Two synthetic techniques were employed for the formation of these polymers. Firstly, the grafting onto approach was used where functional polystyrene prepolymers with either an allyl or vinyl end-groups were synthesised anionically (living anionic polymerization) prior to the coupling of a functional prepolymer using a hydrosilylation reaction with a Karstedt platinum catalyst. This technique was successful and gave insight to the effect of the polystyrene prepolymer graft length has on the grafting efficiency as well as the functional groups needed on the PDMS backbone. Furthermore, the effect of the viscosity (of the PDMS macromonomer) plays on the grafting efficiency was also elucidated. Lastly, the grafting from approach was employed for the formation of PDMS-g-PSty. ATRP, atom transfer radical polymerization, of styrene using a bromoisobutyrate functional PDMS macroinitiator was used for the synthesis of these copolymers. This was accomplished by reacting commercial silane functional PDMS molecules via a hydrosilylation reaction (using a Karstedt catalyst) with allyl-2- bromo-2-methyl-propionate to give a PDMS macroinitiator with bromoisobutyrate functional groups. This will allow for the initiation and growth of polystyrene branches from the PDMS backbone (employing ATRP with a suitable catalyst and ligand). The formation of the endproduct, PDMS-g-PSty, via this route proved to be extremely difficult and largely unsuccessful. Liquid chromatography (LC) at the critical point (LCCC) of polystyrene was used to separate the graft material from homo-polymers which might have formed as well as from the PDMS macromonomer. This technique allows for a very fast chromatographic analysis of the grafting reaction. Under the critical conditions of PSty it was found that the graft copolymer eluted at a lower retention time than the unreacted macromonomer and PSty homopolymer. Two-dimensional chromatography, where LCCC (1st dimension) was coupled to size exclusion chromatography (2nd dimension), was used for the evaluation of the CCD and MMD (molecular mass distribution) of the graft material. LC was furthermore coupled off-line to FTIR and TEM using an LC interface. LCFTIR gave insight to the microstructure of the material, whilst LC-TEM gave insight to the morphological nanostructure of the material. / AFRIKAANSE OPSOMMING: Hibried ent-kopolimere is gesintetiseer uit polistireen (PSty) en polidimetielsiloksaan (PDMS). PSty-g-PDMS is gesintetiseer deur gebruik te maak van die ent-deur tegniek via ‘n konvensionele vrye radikaal polimerisasie proses (VRP). In die reeks is die hoeveelheid PDMS wat geïnkorporeer is, gevarieer deur die hoeveelheid PDMS tot PSty verhouding te verander asook die lengte van die PDMS sytak. Gevolglik het dit toegelaat vir die studie van die effek wat die makromonomeer inhoud, sowel as die taklengte het op die effektiwiteit van die ent-proses. ‘n Tweede reeks is ook gesintetiseer, waar die PDMS die ruggraat vorm van die ko-polimeer, en die stireen die takke vorm van die ko-polimeer. Dus is PDMS-g-PSty gesintetiseer. Twee sintetiese tegnieke is benut vir die vorming van die kopolimere. In die eerste geval is daar van die ent-op tegniek gebruik gemaak waar funksionele polistireen prepolimere met ‘n alliel of ‘n silaan end-groep gesintetiseer is deur gebruik te maak van ‘n anioniese lewendige polimerisasie voor die koppeling van die PDMS makromonomere deur ‘n hidrosililasie proses met ‘n Karstedt platinum katalisator. Die tegniek was suksesvol en het in diepte insig gegee van die effek wat die molekulêre lengte van die polistireen prepolimeer het op die effektiwiteit van die ent-proses, sowel as die minimum hoeveelheid funksionele groepe wat teenwoordig moet wees op die PDMS ruggraat. Verder is die effek wat die viskositeit (van die PDMS makromonomeer) op die ent-proses het, bekend gemaak. Laastens is daar ook van die ent-vanaf tegniek gebruik gemaak vir die vorming van PDMS-g-PSty. AORP, atoom oordrag radikale polimerisasie, van stireen, deur gebruik te maak van ‘n bromoisobutiraat funksionele PDMS makro-inisieerder, is gebruik vir die sintese van die kopolimere. Die makro-inisieerders is bekom deur gebruik te maak van kommersiële silaan funksionele PDMS, en dit is gereageer deur middel van ‘n hidrosililasie proses met alliel-2-bromo- 2-metiel-propionaat. Dit het PDMS makroinisieerders tot gevolg gehad met bromoisobutiraat funksionele groepe. Gevolglik kon stireen takke vanaf die PDMS ruggraat gegroei word deur gebruik te maak van AORP met ‘n geskikte katalisator en ligand. Die vorming van die end-produk, PDMS-g-PSty, deur middel van hierdie roete was onsuksesvol. Vloeistof chromatografie by die kritiese punt van polistireen was gebruik om die ent-produk te skei van die homo-polimere en PDMS makromonomeer. Gevolglik kon die chemiese samestelling van die ent-produk geëvalueer word. Twee-dimensionele chromatografie, waar vloeistof chromatografie by die kritiese punt van polistireen in die eerste vlak gekoppel was aan grootte uitsluitings chromatografie in die tweede vlak, was benut om die chemiese komposisie sowel as die molekul re massa verdeling van die entproduk te verkry. Verder was vloeistof chromatografie indirek aan Fourier-oordrag infrarooi en transmissie elektron mikroskopie (TEM) gekoppel. Eergenoemde het insig gegee tot die mikrostruktuur van die materiaal, terwyl laasgenoemde insig gegee het tot die morfologiese nanostruktuur van die materiaal.

Submitted by Ariane de França Mescoloto null (rianefm@gmail.com) on 2017-02-25T15:53:15Z No. of bitstreams: 1 Dissertação_Ariane_2017.pdf: 4799231 bytes, checksum: 0e27c8b04f680e6a88f1e66a2df4e016 (MD5) / Approved for entry into archive by LUIZA DE MENEZES ROMANETTO (luizamenezes@reitoria.unesp.br) on 2017-03-07T14:05:43Z (GMT) No. of bitstreams: 1 mescoloto_af_me_araiq.pdf: 4799231 bytes, checksum: 0e27c8b04f680e6a88f1e66a2df4e016 (MD5) / Made available in DSpace on 2017-03-07T14:05:43Z (GMT). No. of bitstreams: 1 mescoloto_af_me_araiq.pdf: 4799231 bytes, checksum: 0e27c8b04f680e6a88f1e66a2df4e016 (MD5) Previous issue date: 2017-02-20 / Materiais híbridos orgânico-inorgânicos, constituídos pela combinação de componentes orgânicos e inorgânicos, são homogêneos, apresentam propriedades diferenciadas que refletem a natureza química dos componentes pelos quais foram formados, e são utilizados em diversas aplicações tecnológicas como catalisadores, sensores eletroquímicos, dispositivos ópticos e revestimentos protetores. Este trabalho foi realizado em duas etapas. Primeiramente, foi realizada a síntese e caracterização de um copolímero derivado do politiofeno, P(HTcoAAT), contendo ácido 3-tiofeno-acético (AAT) e 3-hexiltiofeno (HT), sintetizado via copolimerização oxidativa com cloreto férrico e caracterizado químico-estruturalmente por FTIR e RMN 1H e termicamente por TG/DTG. Em seguida, foram preparados filmes híbridos via sol-gel por spin-coating utilizando três óxidos inorgânicos: óxido de silício, titânio e zinco, os quais foram caracterizados opticamente por Espectroscopia no UV-vis e Fluorescência, e morfologicamente por AFM e MEV, além das caracterizações já citadas anteriormente. Os resultados químico-estruturais obtidos comprovaram a eficiência da metodologia usada para a preparação do copolímero e dos híbridos, permitindo a obtenção de matérias com propriedades ópticas interessantes. / Organic-inorganic hybrid materials, formed from organic and inorganic compounds combination, present specific properties that reflect the chemical nature of each precursor compound, and are used for several technological application such as catalists, electrochemical sensors, optical devices and barrier films. This work comprehends two steps: first of all the synthesis of a copolymer derived from polythiophene, P(HTcoTAA) containing 3-thiophene acetic acid (TAA) and 3-hexylthiophene (HT), it was performed from oxidative copolymerization with ferric chloride, and resulting materials characterized by FTIR and 1H NMR spectroscopy and TG/DTG thermal analyses. Following hybrid films from silicium, titanium and zinc oxides were prepared by sol-gel spin-coating and had its optical and morphological characteristics evaluated by UV-vis and Fluorescence spectroscopy, and AFM and SEM microscopy, besides the other characterization before cited. The obtained chemical-structural results show that the used methodology was efficient to prepare both the copolymer and the hybrids, allowing to materials presenting striking optical properties.

Nano-structured materials are widely applied for various applications like photovoltaics, electrochromics and sensors. A challenging task in all these fields is the functionalization of these materials with a molecule of interest for the desired application. This work demonstrate the post grafting of the most important and commonly used nano-structured material, mesoporous TiO2, with different bifunctional molecular linkers. These compounds basically have two functional groups, the phosphonic acid group which coordinates to the TiO2 surface and a positive and negative head group which controls the surface charge and the potential interaction of the surface with species in solution. These two groups are systematically separated by alkyl group of different chain length which controls the hydrophobicity of the surface. It is shown that the new surface modification technique simplifies the molecular requirements for functional surface modifiers considerably. Using a limited set of organic anchors with adjustable head group charge and hydrophobicity, broad range of molecules can be adsorbed onto TiO2. Different applications based on such modified surfaces were explored and demonstrated. The modified surfaces can be used to incorporate different charged guest molecules, electrochromophores and dyes which enable to probe their electrochemistry and photovoltaic properties on the surface. Supra-molecular self assembly inside the modified pores is possible which can be monitored by different methods. The study includes the prepartaion of the modified surfaces and their characterization using different electrochemical methods, FTIR spectroscopy, Quartz Crystal Microbalance, Contact angle and Scanning Electron Microscopy measurements.

No description available.