Chemical Durability of Silicon Oxycarbide Glasses |
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| Authors: | Gian Domenico Sorarù Stefano Modena Emanuel Guadagnino Paolo Colombo James Egan Carlo Pantano |
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| Affiliation: | Universitàdi Trento, Dipartimento di Ingegneria dei Materiali, I-38050 Trento, Italy;Stazione Sperimentale del Vetro, I-30141 Murano (VE), Italy;Universitàdi Bologna, Dipartimento di Chimica Applicata e Scienza dei Materiali, I-40136 Bologna, Italy;Department of Materials Science and Engineering and the Materials Research Institute, The Pennsylvania State University, University Park, Pennsylvania 16802 |
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| Abstract: | Silicon oxycarbide (SiOC) glasses with controlled amounts of Si—C bonds and free carbon have been produced via the pyrolysis of suitable preceramic networks. Their chemical durability in alkaline and hydrofluoric solutions has been studied and related to the network structure and microstructure of the glasses. SiOC glasses, because of the character of the Si—C bonds, exhibit greater chemical durability in both environments, compared with silica glass. Microphase separation into silicon carbide (SiC), silica (SiO2), and carbon, which usually occurs in this system at pyrolysis temperatures of >1000°–1200°C, exerts great influence on the durability of these glasses. The chemical durability decreases as the amount of phase separation increases, because the silica/silicate species (without any carbon substituents) are interconnected and can be easily leached out, in comparison with the SiOC phase, which is resistant to attack by OH− or F− ions. |
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| Keywords: | chemical durability glass silicon oxycarbide |
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