About this Abstract |
Meeting |
MS&T24: Materials Science & Technology
|
Symposium
|
16th Symposium on Green and Sustainable Technologies for Materials Manufacturing and Processing
|
Presentation Title |
Thermodynamic Stability and Carbothermal Reduction in Polymer-Derived SiOC |
Author(s) |
Kathy Lu, Rahul Anand |
On-Site Speaker (Planned) |
Kathy Lu |
Abstract Scope |
This study explores the phase evolution, carbothermal reduction, and energetics in SiOaCb derived from the pyrolysis of trimethylsilyl terminated polyhydromethylsiloxane (PHMS-TMS) from 1200 to 1600°C. High-resolution X-ray photoelectron spectroscopy (XPS) shows notable differences in the constituent bond arrangement between the Si-rich SiOC ceramics and the C-rich SiOC ceramics, which subsequently affects the microstructure of the SiOC systems. Carbothermal reduction starts at lower temperatures than previously reported and indicates no phase separation of SiOC or formation of SiO2 nanodomains. The thermodynamic stability of the thus-obtained SiOC ceramics was evaluated using a Gibbs free energy minimization method. The results suggest that differences in silicon mixed bonding environments and their relative amounts lead to differences in thermodynamic stability. |