Multiscale image analysis of microcellular solids: application to hybrid silica xerogels

A general methodology is proposed to characterize microcellular solids, the structure of which consists of a three-dimensional network of filamentary structures. The analysis is based on transmission electron microscopy observation of the filaments individually and of their spatial arrangement. The micrographs are analyzed with grey-tone digital image analysis techniques, such as opening granulometry and correlation analysis. The methodology is applied to hybrid organic-inorganic low-density silica solids synthesized by the sol-gel method with an organically modified co-reactant. The quantitative impact of the co-reactant on each structural level of the structure is assessed quantitatively.