Macroporous polymer-derived SiO2/SiOC monoliths freeze-cast from polysiloxane and amorphous silica derived from rice husk

作者：Soltani Niloofar^*; Simon Ulla; Bahrami Amin; Wang Xifan; Selve Soren; Epping Jan Dirk; Pech Canul Martin I; Bekheet Maged F; Gurlo Aleksander

来源：Journal of the European Ceramic Society, 2017, 37(15): 4809-4820.

DOI：10.1016/j.jeurceramsoc.2017.06.023

• Polysiloxane
• Freeze-casting
• Porous ceramics
• Rice husk ash
• Polymer-derived ceramics

A freeze-casting route towards macroporous SiOC/SiO2 ceramic nanocomposites from preceramic polymers was developed. Amorphous SiOC/SiO2 monolith with pore channels aligned along the freezing direction were obtained from commercially available methyl-phenyl-vinyl-hydrogen polysiloxane (Silres (R) H62C) and amorphous silica derived from rice husk ash freeze-cast with water or tert-butyl alcohol, crosslinked and pyrolyzed at 1100 degrees C in nitrogen. The influence of processing parameters such as solvent (tert-butyl alcohol or water), polymer to silica ratio (2:1, 1:1, 1:2), cooling rate (2, 4, 6 degrees C/min) and pre-crosslinking of polysiloxane on the porosity and structure of the obtained ceramic nanocomposites were assessed by X-ray tomography, XRD, solid state NMR, scanning electron microscopy and mercury porosimetry. The microstructure of SiOC ceramics derived from the Silres H62C polysiloxane was studied as well.

• 出版日期2017-12