Phase development of silicon oxycarbide nanocomposites during flash pyrolysis
Phase development of silicon oxycarbide nanocomposites during flash pyrolysis
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DOI：
10.1007/s10853-019-03315-z
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发表时间：
2019-04
影响因子：
4.5
通讯作者：
Lixia Wang;K. Lu
中科院分区：
文献类型：
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作者：
Lixia Wang;K. Lu
这项工作的重点是闪蒸热解过程中碳氧化硅（SiOC）纳米复合材料的相开发。评估的三个重要变量是施加的电场、电流限制和热解温度。它们显着促进了 SiOC 微观结构的演化，并在比典型热解过程低 640 °C 的温度下形成更有序的碳和 SiC 相。随着施加电场、热解温度和电流密度的增加，质量损失更高，SiC形成和碳沉淀更广泛，碳相更有序。所得的 SiOC 样品在空气中温度高达 742 °C 时仍保持稳定。根本原因是通过焦耳热和电迁移机制，施加的电场使 C 相和 SiC 相的成核速率大大加快。这项工作为合成高温SiOC纳米复合材料提供了一条加速途径。
This work is focused on phase development of silicon oxycarbide (SiOC) nanocomposites during flash pyrolysis. Three important variables evaluated are applied electric field, current limit, and pyrolysis temperature. They significantly facilitate the microstructure evolution of SiOC and cause the formation of more ordered carbon and SiC phases at > 640 °C lower temperature than the typical pyrolysis process. With the increase in the applied electric field, pyrolysis temperature, and current density, the mass loss is higher, the SiC formation and carbon precipitation are more extensive, and the carbon phase is more ordered. The resulting SiOC samples are stable up to 742 °C in air. The fundamental cause is due to the drastically accelerated nucleation rate for both the C and SiC phases from the applied electrical field, through the mechanisms of Joule heating and electromigration. This work provides an accelerated route to synthesize high-temperature SiOC nanocomposites.