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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Synthesis and application of melamine-based dendrimer/sba-15 hybrid materials

Lunn, Jonathan David 17 September 2007 (has links)
Porous inorganic materials that can be used in applications such as catalysis and separations have been intensely studied due to their potential stability, ease of recovery and high surface areas. Organic-inorganic hybrid materials meet these criteria by exploiting the physical robustness of porous inorganic materials and the chemical functionality of organic materials. While amorphous oxides are widely used industrially as inorganic supports, disordered pore structures make them difficult to characterize. Ordered-mesoporous-silica (OMS), such as SBA-15, that have ordered pores structures simplify characterization and are useful models for studying hybrid materials. Dendrimers, once appropriately functionalized, have high densities of uniformly distributed functional groups. In this thesis, melamine-based dendrimer/SBA-15 hybrids were synthesized and characterized using a wide range of analytical techniques. This thesis shows that the porosity can be independently altered by varying 1) the dendrimer generation, 2) the linker molecule, and 3) the surface amine loading. Cu(II) sequestration results demonstrate that the peripheral functional groups of the dendrimer are readily accessible for binding. This thesis also describes preliminary work toward preparing an enantioselective catalyst using L-proline supported on OMS. This work includes the synthesis and testing of three dendrimer-like proline derivatives. Future work in this area is outlined and will include synthesizing catalysts based on the dendrimer hybrid system previously described. Solution dendrimer syntheses will also be performed to create solution-based catalysts.
2

Synthesis and application of melamine-based dendrimer/sba-15 hybrid materials

Lunn, Jonathan David 17 September 2007 (has links)
Porous inorganic materials that can be used in applications such as catalysis and separations have been intensely studied due to their potential stability, ease of recovery and high surface areas. Organic-inorganic hybrid materials meet these criteria by exploiting the physical robustness of porous inorganic materials and the chemical functionality of organic materials. While amorphous oxides are widely used industrially as inorganic supports, disordered pore structures make them difficult to characterize. Ordered-mesoporous-silica (OMS), such as SBA-15, that have ordered pores structures simplify characterization and are useful models for studying hybrid materials. Dendrimers, once appropriately functionalized, have high densities of uniformly distributed functional groups. In this thesis, melamine-based dendrimer/SBA-15 hybrids were synthesized and characterized using a wide range of analytical techniques. This thesis shows that the porosity can be independently altered by varying 1) the dendrimer generation, 2) the linker molecule, and 3) the surface amine loading. Cu(II) sequestration results demonstrate that the peripheral functional groups of the dendrimer are readily accessible for binding. This thesis also describes preliminary work toward preparing an enantioselective catalyst using L-proline supported on OMS. This work includes the synthesis and testing of three dendrimer-like proline derivatives. Future work in this area is outlined and will include synthesizing catalysts based on the dendrimer hybrid system previously described. Solution dendrimer syntheses will also be performed to create solution-based catalysts.
3

Preparação e caracterização de híbridos orgânico-inorgânicos à base de epoxí-silica / Preparation and characterization of epoxy-silica organic inorganic hybrids

Oblitas Torrico, Ruben Felipe Arturo [UNESP] 15 April 2016 (has links)
Submitted by RUBEN FELIPE ARTURO OBLITAS TORRICO null (ro1485@my.bristol.ac.uk) on 2016-06-08T13:51:30Z No. of bitstreams: 1 Dissertacao.pdf: 2188934 bytes, checksum: 633201227bb5f6a322e3d0dec8645d34 (MD5) / Rejected by Ana Paula Grisoto (grisotoana@reitoria.unesp.br), reason: Solicitamos que realize uma nova submissão seguindo as orientações abaixo: No campo “Versão a ser disponibilizada online imediatamente” foi informado que seria disponibilizado o texto completo porém no campo “Data para a disponibilização do texto completo” foi informado que o texto completo deverá ser disponibilizado apenas 24 meses após a defesa. Caso opte pela disponibilização do texto completo apenas 24 meses após a defesa selecione no campo “Versão a ser disponibilizada online imediatamente” a opção “Texto parcial”. Esta opção é utilizada caso você tenha planos de publicar seu trabalho em periódicos científicos ou em formato de livro, por exemplo e fará com que apenas as páginas pré-textuais, introdução, considerações e referências sejam disponibilizadas. Se optar por disponibilizar o texto completo de seu trabalho imediatamente selecione no campo “Data para a disponibilização do texto completo” a opção “Não se aplica (texto completo)”. Isso fará com que seu trabalho seja disponibilizado na íntegra no Repositório Institucional UNESP. Por favor, corrija esta informação realizando uma nova submissão. Agradecemos a compreensão. on 2016-06-09T16:17:55Z (GMT) / Submitted by RUBEN FELIPE ARTURO OBLITAS TORRICO null (ro1485@my.bristol.ac.uk) on 2016-06-09T16:57:07Z No. of bitstreams: 1 Dissertacao.pdf: 2188934 bytes, checksum: 633201227bb5f6a322e3d0dec8645d34 (MD5) / Approved for entry into archive by Ana Paula Grisoto (grisotoana@reitoria.unesp.br) on 2016-06-13T20:07:22Z (GMT) No. of bitstreams: 1 torrico_rfo_me_araiq_par.pdf: 757530 bytes, checksum: 9e239d69620a743d05fb3a39c914d9bc (MD5) / Made available in DSpace on 2016-06-13T20:07:22Z (GMT). No. of bitstreams: 1 torrico_rfo_me_araiq_par.pdf: 757530 bytes, checksum: 9e239d69620a743d05fb3a39c914d9bc (MD5) Previous issue date: 2016-04-15 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Este projeto visa a investigar a relação entre a estrutura e as propriedades dos materiais epoxi-silica preparados pelo método sol-gel. Os híbridos foram preparados pela reação de cura entre o poly(Bisphenol A-co-epichlorohydrin) (DGBEA) , e o dietil triamina (DETA) assim como pelo processo Sol-Gel de hidrolise e condensação entre GPTMS (3-Glycidoxypropyl)methyldiethoxysilane) e TEOS. Ressonância magnética nuclear (RMN), espectroscopia de fotoelétrons de raios X (XPS), espalhamento de raios X a baixo ângulo (SAXS), espectroscopia de Infravermelho e RAMAN, microscopia de força atômica (AFM) assim como termogravimétria foram utilizadas com o proposito de investigar a morfologia e as propriedades estruturais do material. Finalmente as propriedades anticorrosivas dos filmes foram testadas em uma solução salina por meio de espectroscopia de impedância eletroquímica (EIS). Durante a fase inicial do projeto diferentes amostras com diferentes concentrações de TEOS foram preparadas. A estabilidade térmica como as propriedades anticorrosivas foram testadas. Os resultados mostraram que para maiores concentrações de TEOS, as propriedades anticorrosivas e térmicas dos híbridos melhoram significativamente. Vários resultados interessantes foram obtidos, para híbridos com razoes molares de TEOS : GPTMS : DGBEA = 1 : 1: 1, tendo módulos de impedância de até 1010 Ω cm-2. Durante a segunda fase do projeto, duas series de amostras com concentrações diferentes de GPTMS a TEOS foram preparadas. As propriedades estruturais foram obtidas por meio de Espectroscopia Infravermelho, Raman, RMN e XPS e espalhamento de raios X a baixo ângulo. A hidrofobicidade assim como as propriedades térmicas foram avaliadas por meio de testes de molhabilidade e análise termogravimétrica. Finalmente as propriedades anticorrosivas dos filmes em contato com solução salina foram testadas por meio de espectroscopia de impedância electroquímica. / This work aims to investigate the relationship between the structure and the properties of the sol-gel prepared epoxy-silica materials. The organic-inorganic hybrids were prepared from the curing reaction of poly(Bisphenol A-co-epichlorohydrin) (DGBEA), with Diethyltriamine (DETA) and (3-Glycidoxypropyl)methyltriethoxysilane) (GPTMS) combined with the sol-gel hydrolysis and condensation reactions between Tetraethoxysilane (TEOS) and GPTMS. Nuclear magnetic resonance (NMR), X-ray photoelectron spectroscopy (XPS), Infrared and Raman spectroscopy (IR), Atomic force microscopy, as well as thermogravimetry (TG) have been used with the purpose to investigate the morphological and structural properties of the material. Finally the anticorrosive properties of the hybrid coated carbon steel were evaluated in saline solution using electrochemical impedance spectroscopy (EIS). During the initial phase of the project different samples with increasing concentrations of TEOS have been prepared and their thermal stability as well as their anticorrosive properties were tested. It was found, that for increasing TEOS concentration, the hybrid’s anticorrosive and thermal properties can be improved. Several interesting results were obtained for hybrid coatings at a TEOS : GPTMS : DGBEA = 1 : 1 : 1 ratio, having an impedance modulus of up to 1010 Ω cm-2. During the second phase of the work, a series of epoxy-silica hybrids were synthetized varying the concentrations of GPTMS and TEOS. Their structural properties were characterized by means of Infrared, Raman, solid NMR and XPS spectroscopy. Their hydrophobicity as well as their thermal resistance were evaluated using the drop shape analysis and thermogravimetry. Finally the anticorrosive properties of the coatings in saline solution were tested using electrochemical impedance spectroscopy.
4

Development of Functional Materials Based on Organic-Inorganic Hybrids / 有機-無機ハイブリッドを足場とした機能性材料の創製

Okada, Hiroshi 24 March 2014 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第18294号 / 工博第3886号 / 新制||工||1596(附属図書館) / 31152 / 京都大学大学院工学研究科高分子化学専攻 / (主査)教授 中條 善樹, 教授 吉﨑 武尚, 教授 秋吉 一成 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM
5

Efeito da funcionalização com quitosana e glutaraldeído para obtenção de materiais híbridos a partir do ZnAl1,95(Yb:Er)0,05O4, visando aplicações biotecnológicas.

FURTADO, Cristiane Miranda. 05 October 2018 (has links)
Submitted by Maria Medeiros (maria.dilva1@ufcg.edu.br) on 2018-10-05T11:15:00Z No. of bitstreams: 1 CRISTIANE MIRANDA FURTADO - TESE (PPGEP) 2013.pdf: 8542186 bytes, checksum: dd770c02b3fb0777b254739165ed99da (MD5) / Made available in DSpace on 2018-10-05T11:15:00Z (GMT). No. of bitstreams: 1 CRISTIANE MIRANDA FURTADO - TESE (PPGEP) 2013.pdf: 8542186 bytes, checksum: dd770c02b3fb0777b254739165ed99da (MD5) Previous issue date: 2013-07-11 / CNPq / A utilização de nanopartículas inorgânicas contendo propriedades luminescentes (NPLs) tem recebido uma atenção especial devido a sua utilização para aplicações biológica, tais como marcadores ópticos in vitro e in vivo, em diagnósticos clínicos e como carreadores de fármacos. No entanto, para tais aplicações biotecnológicas as nanopartículas inorgânicas devem ser funcionalizadas com materiais orgânicos que forneçam grupos de ligações com o meio biológico tornando estas nanopartículas biocompatíveis. Neste sentido, este trabalho teve como objetivo sintetizar por reação de combustão o ZnAl1,95(Yb:Er)0,05O4, modificar a superfície com o agente silano 3- amonipropiltrimetoxisilano, e avaliar o efeito da funcionalização destas NPLs com quitosana e glutaraldeído, de forma a se obter um material híbrido que possa ser utilizado em aplicações biotecnológicas, como possíveis marcadores ópticos. As NPLs e o material híbrido foram caracterizados por difração de raio-X, distribuição granulométrica, espectroscopia na região do infravermelho com transformada de Fourrier, microscopia eletrônica de transmissão, microscopia eletrônica de varredura, tensão superficial, teste de solubilidade, análise termogravimétrica e análise térmica diferencial, espectroscopia de excitação e de emissão e citotoxicidade. Os resultados morfológicos demonstram que antes e após a funcionalização com quitosana e com glutaraldeído os tamanhos das partícula foram de 12, 13,2 e 12,8 nm, respectivamente. Bandas de absorção abaixo de 1000 cm-1, característica da estrutura em espinelio e bandas múltiplas em torno de 1100 cm-1 e 1040 cm-1 correspondente ao alongamento assimétrico Si-O, confirmaram a funcionalização das nanopartículas. Os resultados de luminescência indicam a presença das transições características dos íons Yb3+ e Er3+, com um aumento da luminescência observada quando a amostra foi funcionalizada com a quitosana. Pelo teste de citotoxicidade foi observado que as NPLs não funcionalizadas apresentam uma viabilidade celular de 50%, sendo este valor limitante para que se considere este material como não tóxico, contudo ao utilizar a quitosana como agente funcionalizante esta viabilidade celular aumentou para 72%, confirmando um considerável aumento na biocompatibilidade do material. Para o híbrido funcionalizado com glutaraldeído, observou-se que houve diminuição da viabilidade celular para 48%, tornando este material citotóxico. Dessa forma, para obtenção de um marcador óptico as NPLs funcionalizadas com quitosana são mais promissoras devido a sua característica luminescente mais pronunciada, além de que, não é considerado um material citotóxico, o que pode confirmar uma possível aplicação biotecnológica. / The use of inorganic nanoparticles containing luminescent properties (NPLs) has received a special attention because of their use for biological applications, such as optical markers in vitro and in vivo, in clinical diagnostics and as drug carriers. However, for such biotechnological applications inorganic nanoparticles must be functionalized with organic materials that provide groups of connections with the biological environment making these nanoparticles biocompatible. Therefore, this study aimed to synthesize the combustion reaction ZnAl1,95(Yb:Er)0,05O4, modify the surface with silane agent 3-amonipropyltrimethoxysilane, and to evaluate the functionalization effect of these NPLs with chitosan and glutaraldehyde, in order to obtain a hybrid material that can be used in biotechnological applications as possible optical markers. The NPLs and hybrid materials were characterized by X-ray diffraction, particle size distribution, spectroscopy in infrared zone with Fourier transform, transmission electron microscopy, scanning electron microscopy, surface tension, solubility test, thermogravimetric analysis and differential thermal analysis, excitation and emission spectroscopy and cytotoxicity. Morphology results show that before and after functionalization with chitosan and glutaraldehyde particle sizes were of 12.0, 13.2 and 12.8 nm, respectively. Absorption bands below 1000 cm-1, characteristic of the spinel structure and multiple bands around 1100 cm-1 and 1040 cm-1 corresponding to the asymmetric stretching Si-O confirmed the functionalization of the nanoparticles. The luminescence results demonstrate the presence of transitions characteristic of the ions Er3+ and Yb3+, with an increase of luminescence observed when the sample was functionalized with chitosan. By the cytotoxicity test it was observed that the non functionalized NPLs have a cell viability of 50% and this is limiting value to considerate that material as non toxic, but when using chitosan as the functionalizing agent that cell viability increased to 72%, confirming a considerable increase in biocompatibility of the material. For hybrid functionalized with glutaraldehyde, it is observed that there was a decreased cell viability to 48%, which makes this material cytotoxic. Thus, for an optical marker obtaining the NPLs functionalized with chitosan are more promising because of its luminescence characteristic more pronounced, and is not considered a cytotoxic material which can confirm a possible biotechnological application.
6

Materiais multifuncionais baseados em celulose bacteriana

Barud, Hernane da Silva [UNESP] 23 March 2010 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:35:07Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-03-23Bitstream added on 2014-06-13T19:24:28Z : No. of bitstreams: 1 barud_hs_dr_araiq.pdf: 3654254 bytes, checksum: b5905a0e972f7b5cc24710cf4e824b3d (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Esta tese apresenta a preparação e caracterização de novos materiais multifuncionais baseados em celulose produzida pela bactéria Gluconacetobacter xylinus. A celulose bacteriana (CB) possui fórmula molecular idêntica a celulose de plantas (CP) e apresenta uma estrutura de nanofios de celulose dispostos numa rêde tridimensional. Membranas hidratadas ou sêcas foram utilizadas para a preparação de materiais híbridos orgânico-inorgânicos (HOIs) opticamente transparentes baseados em CB e no sistema Bohemita-3-glicidiloxipropiltrimetoxisilano (Boe-GPTS), que foram caracterizados quanto as suas propriedades ópticas, estruturais e mecânicas. Dependendo da utilização de membranas de CB sêcas ou hidratadas obtém-se híbridos com características diferentes. No caso das membranas sêcas observou-se uma redução nos valores de resistência a tração e módulo de Young quando comparado as membranas de CB (112,5 MPa e 12,5 GPa) para (50,5 MPa e 2,8 GPa). Por outro lado a utilização de membranas de CB hidratadas leva a materiais mostrando acréscimo na resistência a tração (116 MPa) e no módulo de Young e (13,7 GPa). As membranas de CB e os novos híbridos foram utilizados como substratos para a preparação de dispositivos flexíveis de emissão de luz, FOLEDs (Flexible Organic Light Emitting Diodes). Os substratos foram recobertos com um filme fino de silica e um filme de ITO. Os FOLEDs foram então obtidos pela deposição de filmes orgânicos por evaporação térmica, na seguinte seqüência: ftalocianina de cobre (CuPC)/ N,N’-difenil-N,N’-bis(1-naftil) (1,1’bifenil)- 4,4’diamina (NPB)/ tris(8-hidroxiquinolina) alumínio (Alq3). Por último foi depositado o contato de alumínio. O FOLED apresentou luminância máxima de (2400 cd/m2 ), resultados similares aos obtidos para o OLED sobre vidro, com as vantagens de flexíbilidade e biocompatibilidade.... / This thesis presents the preparation and characterization of new multifunctional materials based on cellulose produced by bacteria Gluconacetobacter xylinus. Bacterial cellulose (BC) shows molecular formula identical to plant cellulose (PC) and a three-dimensional cellulose nanowires network. Hydrated or dried membranes were utilized for the preparation of the optically transparent organic-inorganic hybrid (OIH) based on BC and Bohemite-3- glycidoxipropyltrimethoxisilane (Boe-GPTS) systems. Theses samples were optically, structurally and mechanically characterized. Different materials characteristics were observed depending on the utilization of dried or hydrated BC membranes precursors. Dried membranes lead to lower values for tensile and Young’s Modulus comparing with pure BC (112. MPa and 12.5 GPa) for (50.5 MPa and 2.8 GPa). Hydrated prcurosor lead to materials presenting an increase in tensile strength (116 MPa) and Young's modulus (13.7 GPa). BC membranes and the new hybrids were utilized as substrate for preparation of flexible displays emitting light, FOLEDs (Flexible Organic Light Emitting Diodes). The substrates were coated with thin films of silica and ITO. FOLEDs were obtained by thermal evaporation, in the following sequence: copper phthalocyanine (CuPc) /(N,N΄-bis(1- naphtyl)-N,N΄-diphenyl-1,1´-biphenyl-4,4´-diamine) (NPB) /tris(8-hydroxyquinoline) aluminum and the aluminum contact. The total maximum luminance values for the FOLED was 2400 (cd/m2 ), which is comparable with a glass OLED prepared with similar characteristics. Photocromic hybrids were prepared by the incorporation of phosphotungstic acid (H3PW12O40) in BC membranes. The BC/PWA OIHs were characterized by vibrational spectroscopies (Raman scattering and infrared absorption), electron microscopy and thermal analysis. In order to elucidate the photochromic phenomena electronic spectroscopy... (Complete abstract click electronic access below)
7

Novos materiais multifuncionais baseados em celulose bacteriana /

Barud, Hernane da Silva. January 2010 (has links)
Orientador: Sidney José Lima Ribeiro / Banca: Wilton Rogério Lustri / Banca: Agnieszka Joanna Pawlicka Maule / Banca: Rosana Maria Nascimento de Assunção / Banca: Marco Cremona / Resumo: Esta tese apresenta a preparação e caracterização de novos materiais multifuncionais baseados em celulose produzida pela bactéria Gluconacetobacter xylinus. A celulose bacteriana (CB) possui fórmula molecular idêntica a celulose de plantas (CP) e apresenta uma estrutura de nanofios de celulose dispostos numa rêde tridimensional. Membranas hidratadas ou sêcas foram utilizadas para a preparação de materiais híbridos orgânico-inorgânicos (HOIs) opticamente transparentes baseados em CB e no sistema Bohemita-3-glicidiloxipropiltrimetoxisilano (Boe-GPTS), que foram caracterizados quanto as suas propriedades ópticas, estruturais e mecânicas. Dependendo da utilização de membranas de CB sêcas ou hidratadas obtém-se híbridos com características diferentes. No caso das membranas sêcas observou-se uma redução nos valores de resistência a tração e módulo de Young quando comparado as membranas de CB (112,5 MPa e 12,5 GPa) para (50,5 MPa e 2,8 GPa). Por outro lado a utilização de membranas de CB hidratadas leva a materiais mostrando acréscimo na resistência a tração (116 MPa) e no módulo de Young e (13,7 GPa). As membranas de CB e os novos híbridos foram utilizados como substratos para a preparação de dispositivos flexíveis de emissão de luz, FOLEDs (Flexible Organic Light Emitting Diodes). Os substratos foram recobertos com um filme fino de silica e um filme de ITO. Os FOLEDs foram então obtidos pela deposição de filmes orgânicos por evaporação térmica, na seguinte seqüência: ftalocianina de cobre (CuPC)/ N,N'-difenil-N,N'-bis(1-naftil) (1,1'bifenil)- 4,4'diamina (NPB)/ tris(8-hidroxiquinolina) alumínio (Alq3). Por último foi depositado o contato de alumínio. O FOLED apresentou luminância máxima de (2400 cd/m2 ), resultados similares aos obtidos para o OLED sobre vidro, com as vantagens de flexíbilidade e biocompatibilidade .... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This thesis presents the preparation and characterization of new multifunctional materials based on cellulose produced by bacteria Gluconacetobacter xylinus. Bacterial cellulose (BC) shows molecular formula identical to plant cellulose (PC) and a three-dimensional cellulose nanowires network. Hydrated or dried membranes were utilized for the preparation of the optically transparent organic-inorganic hybrid (OIH) based on BC and Bohemite-3- glycidoxipropyltrimethoxisilane (Boe-GPTS) systems. Theses samples were optically, structurally and mechanically characterized. Different materials characteristics were observed depending on the utilization of dried or hydrated BC membranes precursors. Dried membranes lead to lower values for tensile and Young's Modulus comparing with pure BC (112. MPa and 12.5 GPa) for (50.5 MPa and 2.8 GPa). Hydrated prcurosor lead to materials presenting an increase in tensile strength (116 MPa) and Young's modulus (13.7 GPa). BC membranes and the new hybrids were utilized as substrate for preparation of flexible displays emitting light, FOLEDs (Flexible Organic Light Emitting Diodes). The substrates were coated with thin films of silica and ITO. FOLEDs were obtained by thermal evaporation, in the following sequence: copper phthalocyanine (CuPc) /(N,N΄-bis(1- naphtyl)-N,N΄-diphenyl-1,1'-biphenyl-4,4'-diamine) (NPB) /tris(8-hydroxyquinoline) aluminum and the aluminum contact. The total maximum luminance values for the FOLED was 2400 (cd/m2 ), which is comparable with a glass OLED prepared with similar characteristics. Photocromic hybrids were prepared by the incorporation of phosphotungstic acid (H3PW12O40) in BC membranes. The BC/PWA OIHs were characterized by vibrational spectroscopies (Raman scattering and infrared absorption), electron microscopy and thermal analysis. In order to elucidate the photochromic phenomena electronic spectroscopy... (Complete abstract click electronic access below) / Doutor
8

Matériaux hybrides organique/inorganique multifonctionnels à structuration hiérarchique obtenus par voie sol-gel et/ou auto-assemblage / Multifunctional hierarchically-structured organic/inorganic hybrids prepared through sol-gel and/or self-assembly

Peixoto Fernandes, Mariana Sofia 02 December 2011 (has links)
Cette thèse décrit la préparation de matériaux hybrides organiques-inorganiques aux propriétés ciblées. Dans la première partie de ce travail, le procédé sol-gel a été couplé aux techniques d'auto-assemblage pour la préparation de matériaux hybrides organiques-inorganiques. Cette combinaison est d'un grand intérêt, non seulement d'un point de vue fondamental, mais aussi parce qu'elle permet la production de nouveaux matériaux hybrides fonctionnels à structuration hiérarchique. Deux familles ont été étudiées, avec deux types de liens : urée ou uréthane. L'influence de paramètres tels que la longueur des chaînes alkyle et alkylène et le solvant sur la nanostructure a été analysée. Le comportement hystérétique d'une classe des matériaux à liens uréthane a été exploité. Dans la seconde partie de ce manuscrit, le procédé sol-gel a été utilisé pour préparer des électrolytes hybrides organiques-inorganiques composés de biohybrides siloxane/poly(e-caprolactone) à liens uréthane, contenant des proportions fortement variables de triflate de potassium dans un cas, et un mélange de triflates de lithium et d'europium dans l'autre exemple. Dans les deux cas, des prototypes de dispositifs électrochromes ont été construits, avec une structure sandwich constituée de quatre couches comprenant deux couches externes formées de films d'oxyde conducteur transparent, un film électrochrome d'oxyde de tungstène (WO3) et une couche active conductrice d'ions constituée des échantillons d'ormolyte. Les transmittances optiques moyennes, les contrastes de couleur et les temps de réponse associés aux processus de coloration/décoloration ont été déterminés. Le changement de couleur a été quantifié dans le prototype à base du mélange Li/Eu.Le carbonate de calcium (CaCO3) est un composé minéral très important dans la Nature, qui peut exister sous six formes polymorphiques différentes. Parmi elles, la phase amorphe (ACC) métastable est utilisée par beaucoup d'organismes comme intermédiaire transitoire pour former des objets composés de monocristaux de calcite ou d'aragonite à morphologie élaborée. L'ACC a un potentiel inédit dans le domaine de l'orthopédie étant donné sa vitesse de croissance, son caractère immunogène et les propriétés mécaniques des os qui en dérivent. Dans cette étude, nous avons utilisé une méthode de synthèse faisant appel à la poly(vinylpyrrolidone) pour retarder la cristallisation de l'ACC et à plusieurs liquides ioniques et tensio-actifs pour changer la morphologie de calcite. / This thesis is focused on the preparation of organic-inorganic hybrid systems with targeted properties. In the first part of the work, the sol-gel process and self-assembly techniques were employed for the preparation of organic-inorganic hybrid materials. This combination is of great interest, not only from the fundamental point of view, but also because it allows the production of novel functional and hierarchically structured hybrid materials. Two families of materials were obtained, featuring two different types of cross links: urea and urethane. The influence of parameters such as the alkyl and alkylene chain length and the solvent on the nanostructure was analyzed. In the second part of the work the sol-gel method was used to prepare organic-inorganic hybrid electrolytes composed of novel di-urethane cross-linked poly(e-caprolactone)/siloxane biohybrids incorporating a wide range of potassium triflate concentration in one example and a mixture of lithium triflate and europium triflate in the other example. In both cases prototype ECDs have been constructed using a four layer-sandwich configuration comprising two outermost layers composed of transparent conducting oxide (TCO) films, an EC film of tungsten oxide (WO3) and an IC active layer of selected ormolyte samples. The average optical transmittance, colour contrast, optical density and device response time associated with the colouring/bleaching processes have been determined. The colour change has been quantified in the prototype based on the Li/Eu mixture. Calcium carbonate (CaCO3) is an important biomineral in Nature, that can exist in six different polymorphic forms. Among them, the metastable amorphous CaCO3 phase (ACC) is used in many organisms as a transient intermediate to form single crystals of calcite and aragonite with elaborate shapes. ACC has a tremendous potential in the orthopedic field. Herein we have employed poly(vinylpyrrolidone) to retard the crystallization of ACC. In addition, several ionic liquids and surfactants were employed to tune the morphology of calcite.
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Development of Functional Materials Based on Polyhedral Oligomeric Silsesquioxanes / POSSを基盤とした機能性材料の創製

Ueda, Kazunari 23 March 2017 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第20402号 / 工博第4339号 / 新制||工||1672(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 中條 善樹, 教授 澤本 光男, 教授 古賀 毅 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM
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Organic-inorganic hybrid photovoltaics based on organometal halide perovskites

Lee, Michael M. January 2013 (has links)
This thesis details the development of a novel photovoltaic device based on organometal halide perovskites. The initial focus of this thesis begins with the study of lighttrapping strategies in solid-state dye-sensitised solar cells (detailed in chapter 3). While I report enhancement in device performance through the application of near and far-field light-trapping techniques, I find that improvements remain step-wise due to fundamental limitations currently employed in dye-sensitised solar cell technology— notably, the available light-sensitising materials. I found a promising yet under researched family of materials in the methyl ammonium tri-halide plumbate perovskite (detailed in chapter 4). The perovskite light-sensitiser was applied to the traditional mesoscopic sensitised solar cell device architecture as a replacement to conventional dye yielding world-record breaking photo-conversion e!ciencies for solid-state sensitised solar cells as high as 8.5%. The system was further developed leading to the conception of a novel device architecture, termed the mesoporous superstructured solar cell (MSSC), this new architecture replaces the conventional mesoporous titanium dioxide semiconductor with a porous insulating oxide in aluminium oxide, resulting in very low fundamental losses evidenced through high photo-generated open-circuit voltages of over 1.1 V. This development has delivered striking photo-conversion ef- ficiencies of 10.9% (detailed in chapter 6).

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