Synthesis of hierarchical porous silicon oxycarbide ceramics from preceramic polymer and wood biomass composites

Alumina-mullite composites with low shrinkage can be made by reaction bond using mixtures of alumina, aluminum and silicon carbide. In this work, an alternative route is used to produce alumina composites with low shrinkage. Here alumina samples containing additions of 10 and 20 wt% of a preceramic polymer were warm-pressed and treated in the range of 900 -1500°C to produce alumina based composites. The obtained composites were analyzed by linear shrinkage and compared to pure alumina samples sintered at the same temperature range. It were also evaluated the density variation and crystalline phases formed during heat treatment of alumina composites. Results showed that alumina-silicon oxycarbide and alumina-mullite composites were obtained with lower shrinkage than pure alumina samples.

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Preparation of Dense and Porous Silicon Oxycarbide Submicrometer-Sized Spheres Using a Modified Stöber Process

Journal of the American Ceramic Society ◽

10.1111/j.1551-2916.2011.04732.x ◽

2011 ◽

Vol 94 (11) ◽

pp. 3819-3824 ◽

Cited By ~ 17

Author(s):

Sandra Dirè ◽

Valeria Tagliazucca ◽

Livio Salvadori ◽

Gian Domenico Sorarù

Keyword(s):

Porous Silicon ◽

Silicon Oxycarbide ◽

Stöber Process

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Towards Porous Silicon Oxycarbide Materials: Effects of Solvents on Microstructural Features of Poly(methylhydrosiloxane)/Divynilbenzene Aerogels

Materials ◽

10.3390/ma11122589 ◽

2018 ◽

Vol 11 (12) ◽

pp. 2589 ◽

Cited By ~ 2

Author(s):

Susana Aguirre-Medel ◽

Prasanta Jana ◽

Peter Kroll ◽

Gian Sorarù

Keyword(s):

Porous Silicon ◽

Pore Formation ◽

Supercritical Drying ◽

Silicon Oxycarbide ◽

Cross Linking ◽

Solvent Exchange ◽

Hydrosilylation Reaction ◽

Liquid Co2 ◽

Major Factors ◽

The Impact

We investigate the impact of solvents on the microstructure of poly(methylhydrosiloxane)/divinylbenzene (PMHS/DVB) aerogels. The gels are obtained in highly diluted conditions via hydrosilylation reaction of PMHS bearing Si-H groups and cross-linking it with C=C groups of DVB. Polymer aerogels are obtained after solvent exchange with liquid CO2 and subsequent supercritical drying. Samples are characterized using microscopy and porosimetry. Common pore-formation concepts do not provide a solid rationale for the observed data. We postulate that solubility and swelling of the cross-linked polymer in various solvents are major factors governing pore formation of these PMHS/DVB polymer aerogels.

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Gradient pore size distributions in porous silicon oxycarbide materials

Journal of the European Ceramic Society ◽

10.1016/j.jeurceramsoc.2007.12.026 ◽

2008 ◽

Vol 28 (9) ◽

pp. 1871-1879 ◽

Cited By ~ 19

Author(s):

A. Tamayo ◽

J. Rubio ◽

R. Peña-Alonso ◽

F. Rubio ◽

J.L. Oteo

Keyword(s):

Porous Silicon ◽

Pore Size ◽

Silicon Oxycarbide ◽

Size Distributions ◽

Pore Size Distributions

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Electrochemical Impedance Spectroscopy of Dense Silica and Porous Silicon Oxycarbide

Electrochemical and Solid-State Letters ◽

10.1149/1.2751836 ◽

2007 ◽

Vol 10 (9) ◽

pp. G63 ◽

Cited By ~ 6

Author(s):

K. Sidi Ali Cherif ◽

S. Kordic ◽

J. Farkas ◽

S. Szunerits

Keyword(s):

Electrochemical Impedance Spectroscopy ◽

Porous Silicon ◽

Impedance Spectroscopy ◽

Electrochemical Impedance ◽

Silicon Oxycarbide

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Fabrication of Foam-Type Porous Silicon Carbide without Cracks and Hollow Struts

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.369.48 ◽

2016 ◽

Vol 369 ◽

pp. 48-52

Author(s):

Jeong Won Bang ◽

Soo Ryong Kim ◽

Young Hee Kim ◽

Dong Geun Shin ◽

Yoon Joo Lee ◽

...

Keyword(s):

Silicon Carbide ◽

Porous Silicon ◽

Silicon Oxycarbide ◽

X Ray Diffraction ◽

Porous Silicon Carbide ◽

Air Atmosphere ◽

Sic Ceramics ◽

Sic Ceramic ◽

Curing Condition ◽

Porous Sic

Foam-type porous silicon carbide (SiC) ceramics without cracks and hollow struts were fabricated using the polymer replica method with polycarbosilane (PCS) and polyurethane (PU) foam as the starting materials. The synthesized porous SiC was analyzed using X-ray diffraction and scanning electron microscopy. The results revealed that a porous SiC ceramic structure was formed with a dense framework at a low temperature of 1200°C. During the heat-treatment process, the PCS experienced an organic–inorganic transformation and then converted to the SiC ceramics. It was determined that the organic–inorganic transformation of PCS, which was the stage of silicon oxycarbide formation, is affected by the curing condition. In this study, the optimum curing condition was determined to be an air atmosphere at 200°C for 7 h.

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