Polymer-derived porous ceramics from novel silicon based-preceramic/sucrose systems

MARIANO HERNÁN TALOU; JAVIER OSWALDO BOLAÑOS RIVERA; MARÍA ANDREA CAMERUCCI

CERAMICS INTERNATIONAL

ELSEVIER SCI LTD

Lugar: Amsterdam; Año: 2023 vol. 49 p. 7600 - 7612

0272-8842

Porous Si/C/O/(N) ceramic bodies were developed by the direct consolidation of novel liquid silicon-based preceramic polymer/porogen (methacryloxypropyl silsesquioxane/sucrose) systems, burnout, and N2 pyrolysis (1300-1500 °C), and they were characterized via open porosity, volumetric shrinkage, and mass loss measurements. The evolution of phases as temperature increased was analyzed using XRD, TGA-mass spectrometry tests, and 29Si NMR. The free carbon phase was characterized via Raman spectroscopy, and its content was determined using a carbon analyzer. Porous microstructures were analyzed by SEM/EDS and Hg-porosimetry, and by measuring the N2 adsorption/desorption and specific surface area. The final ceramics exhibited a hierarchical porosity composed of large irregular pores that grew with temperature, together with a lower volume of meso- and micropores. β-SiC whiskers and faceted hexagonal crystals of α-Si3N4 were observed inside of cavities. The presence of meso- and micropores explained the high specific surface area achieved in the material pyrolyzed at 1500 °C.