Structural characterization and thermal oxidation resistance of silicon oxycarbides produced by polysiloxane pyrolysis

Kolář, František; Machovič, Vladimı́r; Svı́tilová, Jaroslava; Borecká, Lenka

doi:10.1016/j.matchemphys.2004.02.011

Cited by 58 publications

(26 citation statements)

References 32 publications

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“…The absorption at around 1700 cm ¹1 , tentatively assigned to carbonyl groups, has been reported before in HF etched SiOCs 8) even in conjunction with the band at ³1600 cm ¹1 assigned to graphitic structures. 22) These findings (the simultaneous presence of the two bands assigned to C=O and graphitic carbon and remembering that ATR technique enhances the contribution of the surface) suggest that: (i) the C=O moieties are connected to the Csp 2 planes rather than with the C atoms bonded to Si atoms in the SiOC network and (ii) the surface created by the HF attack is rich in carbon which is present either as SiC bonds or as graphitic carbon. Concerning the origin of the carbonyl groups, this is not clear now.…”

Section: ¹1mentioning

confidence: 99%

Processing and characterization of polymer derived SiOC foam with hierarchical porosity by HF etching

Sorarù

Campostrini

Ejigu

et al. 2016

J. Ceram. Soc. Japan

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A simple process for synthesizing SiOC foams with low density (45115 kg/m 3 ) and high porosity (9598%) is reported here. The process involves the impregnation of a flexible polyurethane foam with a preceramic polymer solution and pyrolysis in the inert atmosphere. SEM analysis showed that the resultant SiOC foam had a fully open interconnected porous structure with dense struts. N 2 adsorption test performed on the as-pyrolyzed SiOC foams showed very low surface area, which can be increased by leaching out the SiO 2 -rich network by HF, leaving behind a mesoporous C-rich SiOC foam. The remarkably high surface area up to 147 m 2 /g (7350 m 2 /liter) has been reached after 24 h etching. HF etching leads to a decrease of the compressive strength. However, a good combination of compressive strength (³80 kPa), porosity (95%) and surface area (7315 m 2 /liter) of the foam has been obtained and it makes the SiOC foam a potential candidate for specific applications.

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Section: ¹1mentioning

confidence: 99%

Processing and characterization of polymer derived SiOC foam with hierarchical porosity by HF etching

Sorarù

Campostrini

Ejigu

et al. 2016

J. Ceram. Soc. Japan

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“…Lukosil 901 is xylene solution of poly[methyl(phenyl)]siloxane. Composition and properties of Lukosil 901 (starting liquid resin, cured and pyrolyzed ones) are described in papers [1,4,5].…”

Section: Sample Preparationmentioning

confidence: 99%

“…By the pyrolysis of cured polysiloxanes in an inert atmosphere, compact glassy materials are formed which are very resistant to oxidation at high temperature [1][2][3][4][5]. These materials represent modifications of a quartz glass in which some of the pairs of oxygen atoms are substituted by an atom of carbon.…”

Section: Introductionmentioning

confidence: 99%

“…These materials represent modifications of a quartz glass in which some of the pairs of oxygen atoms are substituted by an atom of carbon. In addition, certain portions of the free carbon structures are distributed loosely dissipated in the siliconoxycarbide network [1,[4][5][6][7][8]. Strictly speaking, the carbon is not present in elemental form but as structures with both aromatic and aliphatic C-H bonds [4,5].…”

Section: Introductionmentioning

confidence: 99%

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Cobalt-containing silicon oxycarbide glasses derived from poly[methyl(phenyl)]siloxane and cobalt phthalate

Kolář

Machovič

Svı́tilová

2006

Journal of Non-Crystalline Solids

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“…With the formation of free carbon in SiOC, the SiOC system can be oxidized at high temperatures, compromising its thermal stability and thus its electrical conductivity. 21 Because of these antagonistic behaviors, there has been almost no interest in examining high carbon content SiOCs for high temperature electrical conductivity purposes. A surprising finding that has not caused as much attention as it deserves is the high temperature stability of carbon-rich SiOCs created based on polyhydromethylsiloxane (PHMS) and carbon-rich additive divinylbenzene (DVB).…”

mentioning

confidence: 99%

Thermal stability and electrical conductivity of carbon-enriched silicon oxycarbide

Erb

Liu

2016

J. Mater. Chem. C

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Silicon oxycarbide (SiOC) is an interesting polymer-derived system that can be tailored to embody many different properties such as lightweight, electrochemical activity, and high temperature stability. One intriguing property that has not been fully explored is the electrical conductivity for the carbon-rich SiOC compositions. In this study, a carbon-rich SiOC system is created based on the crosslinking and pyrolysis of polyhydromethylsiloxane (PHMS) and divinylbenzene (DVB) mixed precursors. The carbonrich nature can effectively delay SiOC phase separation and crystallization into SiO 2 and SiC during pyrolysis. In an oxidizing air atmosphere, the SiOC materials are stable up to 1000 1C with o0.5 wt% weight loss. Before the onset of electrical conductivity drop at B400 1C, the material has electrical conductivity as high as 4.28 S cm À1. In an inert argon atmosphere, the conductivity is as high as 4.64 S cm À1.This new semi-conducting behavior with high thermal stability presents promising application potential for high temperature MEMS devices, protective coatings, and bulk semi-conducting components that must endure high temperature conditions.

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Structural characterization and thermal oxidation resistance of silicon oxycarbides produced by polysiloxane pyrolysis

Cited by 58 publications

References 32 publications

Processing and characterization of polymer derived SiOC foam with hierarchical porosity by HF etching

Processing and characterization of polymer derived SiOC foam with hierarchical porosity by HF etching

Cobalt-containing silicon oxycarbide glasses derived from poly[methyl(phenyl)]siloxane and cobalt phthalate

Thermal stability and electrical conductivity of carbon-enriched silicon oxycarbide

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