Texture and micro-nanostructure of porous silicon oxycarbide glasses prepared from hybrid materials aged in different solvents

The influence of the aging conditions of the preceramic hybrid material on the microstructure of silicon oxycarbide (SiOC) glasses derived therefrom has been highlighted. The textural and structural properties of the glasses are modified by aging the hybrid precursor in different environments. Three solvents have been employed as aging media to produce macroporous SiOC ceramics with porosities in the range between 30 and 70 vol.%.It has been concluded that the polarity and chemical characteristics of the solvent plays an important role on the surface characteristics and structure of the obtained SiOC glass. Raman spectroscopy and Small Angle X-ray scattering reveal the presence of different nanodomain sizes depending on the polymeric fraction in the preceramic network. The free carbon phase developed during the hybrid-to-ceramic conversion turn out to have a high influence on the growth of the silica nanodomains and thus on the nanostructure of the obtained ceramic.