Structural studies of TEOS-tetraethoxytitanate based hybrids

Nocuń, Marek; Siwulski, S.; Leja, E.; Jedliński, J.

doi:10.1016/j.optmat.2005.01.014

Cited by 20 publications

(14 citation statements)

References 16 publications

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“…The value of the thermal effect according to DSC results (figure 7) is not in contradiction to this supposition. These results are in agreement with the reported ones (Que et al 2000;Nocun et al 2005). The absorption band at 1188 cm -1 shifts to 1206 cm -1 .…”

Section: Thermal Decompositionsupporting

confidence: 93%

“…The bands at 2960-2855 cm -1 belonging to CH 2 and CH 3 , as well as those at 1472 cm -1 (δ(CH 2 )) and at 696 cm -1 (Si-CH 2 ) disappear (figure 2B (10)). The destruction of the organic components of ormosils type precursors has also been found in the same temperature interval by other researchers (Zaharescu et al 1999(Zaharescu et al , 2003Que et al 2000;Nocun et al 2005) depending on the type of organic component and on the ratio between TEOS and ormosil-precursor. When heating was performed in inert atmosphere, the Si-CH 3 bond disrupts at 700-800°C.…”

Section: Thermal Decompositionsupporting

confidence: 70%

“…They also have discussed a hypothesis proposed for the chemistry of the processes taking place. Structural and thermochemical investigations of TEOS-tetraethoxytitanate-ormosils based hybrids used for obtaining corrosion protective coatings have been carried out based on earlier studies (Que et al 2000;Nocun et al 2005). The MtEOS, triethoxyvinylsilane, trimethoxymethylsilane (Zaharescu et al 2001(Zaharescu et al , 2003Nocun et al 2005) and 3-glicidoxypropyltrimethoxysilane studied by Nocun et al (2005) have been used both solely and in mixtures as precursors.…”

Section: Introductionmentioning

confidence: 99%

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Thermochemical behaviour of Ru(II) complex-SiO2 microcomposites

et al. 2007

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The results from DSC and thermogravimetric analysis of gels produced from a mixture of tetraethoxysilane (TEOS) and octyltriethoxysilane (OtEOS) both with and without immobilized Ru(II) tris(4,7-diphenyl-1,10-phenanthroline) dichloride as well as DSC and TG data for films deposited by deep-or spincoating from the same gels, are reported. The initial products are characterized by elemental analysis, IR, solid state NMR and mass spectroscopy. Elemental analysis and IR spectroscopy are applied for identification of some of the intermediates obtained after heating at different temperatures. The final products are characterized by X-ray diffractometry. A hypothesis for the thermodecomposition processes taking place is proposed. The results reported contribute to elucidation of the properties as well as the temperature intervals in which the studied microcomposites could be used as sensing components of oxygen sensors.

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Section: Thermal Decompositionsupporting

confidence: 93%

Section: Thermal Decompositionsupporting

confidence: 70%

Section: Introductionmentioning

confidence: 99%

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Thermochemical behaviour of Ru(II) complex-SiO2 microcomposites

et al. 2007

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“…[24][25][26] Outra banda de absorção importante está relacionada a vibrações da ligação Si-OH em ~950 cm -1 . [27][28][29] No caso das resinas epóxi novolaca, entre os vários picos de absorção que podem ser observados em seus espectros FTIR, o de maior importância é o pico em ~912 cm -1 referente ao anel epóxi. Outros picos importantes situam-se em ~3000 cm -1 , atribuído ao estiramento CH no anel epóxi, pico em 1509 cm -1 , atribuído ao estiramento das ligações C=C dos anéis benzênicos, pico em ~1238 cm -1 , atribuído principalmente ao estiramento da ligação éter anel aromático-oxigênio, e o pico em ~1030 cm -1 , atribuído à vibração do grupo -OH 2 -.…”

Section: Resultados E Discussão Análises Dos Espectros De Radiação Deunclassified

Revestimentos de alta camada obtidos com a modificação de resinas epóxi novolaca pela reação com organo-siloxano e catálise ácida

et al. 2016

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publicado na web em 12/10/2016 HIGH LAYER COATING OBTAINED IN THE REACTION OF MODIFIED NOVOLAC EPOXYS RESINS WITH ORGANOSILOXANES THROUGH ACID CATALYSIS. Epoxy resins are an important class of thermostable polymers, widely used in structural applications or as adhesives. However, the low fracture resistance is their main weakness in many applications. Due to this fact, this study aims to modify a polymer matrix based on a novolac epoxy resin with an organo siloxane (AMS). The final properties of cured epoxys resins are affected by the curing process and the coatings modified in this study with AMS and cured with acid catalyst presented greater resistance to thermal decomposition compared to that cured with Aradur, demonstrating a higher content of crosslinking in the siloxane polyether and the novolak epoxy resin chains. This epoxy matrix modified was used to prepare coatings whose films applied to 1020 steel surfaces presented a resistance of 10 10 Ohm-cm -2 . This resistance value is one order of magnitude greater than that of epoxy resins films modified by siloxanes in published studies, which demonstrates a potential economy in terms of maintenance costs of metal structures and machines used in power plants (UTE). To obtain the developed inks in pilot plant scale, it was used an aromatic polyamine as curing agent, characterizing the product obtained as an epoxy bi-component paint for commercial use.Keywords: Corrosion, novolac epoxy resin, interpenetrating polymer network-IPN, polyether siloxane, coatings. INTRODUÇÃOAs resinas epóxi são uma importante classe de polímeros termoestáveis, amplamente utilizadas em aplicações estruturais ou como adesivos, devido a suas características de alta tensão e módulo, fácil processamento, boa resistência química e térmica e alta aderência a muitos substratos. Os sistemas epóxi apresentam pequena contração após a cura (em média, 2%), o que indica a necessidade de um baixo grau de rearranjo molecular para formar o sistema curado. Quanto à estabilidade química, o epóxi é um dos termorrígidos mais inertes, além de possuir boa estabilidade dimensional. Entretanto, revestimentos à base de resinas epóxi apresentam hidrofobicidade, baixas resistência ao impacto e à exposição a ambientes abertos, estabilidade térmica relativamente baixa e, em muitas aplicações, sua principal desvantagem é sua baixa resistência à fratura. Por essas razões, as resinas epóxi são frequentemente modificadas buscando aprimorar suas características.Conforme estudo de Gu et al., 1 têm sido introduzidas nanopartículas inorgânicas (SiO 2 , ZrO 2 , ZnO) em matrizes epóxi que atuam preenchendo os defeitos, como microfissuras e vazios, do revestimento epóxi, com o intuito de aprimorar suas propriedades anticorrosivas modificando seu efeito como barreira física. A otimização de propriedades, principalmente mecânicas, das resinas epóxi e dos polímeros termofixos também pode ser alcançada pela modificação da estrutura do polímero, aumentando-se a cadeia em pontos de entrecruzamento. 2 De forma geral, a introdução...

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“…The broad spectral feature at $1090 cm -1 is attributed to both the Si-O-Si (asymmetric stretch) and the Si-O-C peaks, including the Si-O-ethoxy group stretch. 14,[22][23][24] The Zr-based sol has two specific features at $420 and 650 cm -1 , which have been associated with the Zr-O-Zr bond. 14 The zirconiaGlymo sol-gel spectrum indicates a variety of changes upon mixing and reaction.…”

Section: Fabrication Of Sol-gel Waveguidesmentioning

confidence: 99%

Fabrication and Properties of an Asymmetric Waveguide Containing Nanoparticles

Zhang

Kuech

2007

Journal of Elec Materi

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A wavelength-tunable light-emitting source consisting of a multilayer asymmetric waveguide structure was designed, modeled, and fabricated on a silicon substrate. The structure has two layers: a silica cladding and a zirconia-Glymo (c-glycidoxypropyltrimetoxysilane) sol-gel-based waveguide layer. CdS and CdSe/ZnS colloidal nanoparticles (NPs) used as light-emission sources were incorporated into the waveguide layer. These NPs are however unstable in a low-pH environment. A zirconia-Glymo sol-gel film using acetylacetone as the zirconium chelating agent was developed, thus eliminating the often used acetic acid from the sol-gel synthesis and preserving the NPs in the waveguide formation process. The acetylacetone chelating agent allowed for a high degree of cross-linking between the Zr and the Glymo as indicated by the Zr-O-Si absorption observed by infrared spectroscopy. The incorporation of the photoemissive CdSe/ZnS core/shell nanoparticles within the zirconia gel asymmetric slab waveguide was demonstrated as a means to create miniature multispectral light sources.

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Structural studies of TEOS-tetraethoxytitanate based hybrids

Cited by 20 publications

References 16 publications

Thermochemical behaviour of Ru(II) complex-SiO2 microcomposites

Thermochemical behaviour of Ru(II) complex-SiO2 microcomposites

Revestimentos de alta camada obtidos com a modificação de resinas epóxi novolaca pela reação com organo-siloxano e catálise ácida

Fabrication and Properties of an Asymmetric Waveguide Containing Nanoparticles

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