3D Multiscale Characterization of Silica Aerogels Composites

Perret, Amandine; Foray, Geneviève; Roiban, Lucian; Masenelli‐Varlot, Karine; Maire, Éric; Adrien, Jérôme; Yrieix, Bernard

doi:10.1002/9781118990278.ch5

Cited by 1 publication

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“…Several studies performed by X-ray tomography [24][25][26] have succeeded in insight into the inter-granular three-dimensional porous network distribution. The upper part of the porosity curve, which is a major contributor to the gas thermal conductivity, has been fully described within samples of a few centimeters; the even 3D distribution of micron size adsorbant particle has been conrmed.…”

Section: -23mentioning

confidence: 99%

Advanced three dimensional characterization of silica-based ultraporous materials

et al. 2016

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conditions. Such a low value requires reducing air molecule mobility in highly porous materials, and silica-based superinsulation materials (SIM) made of packed nanostructured silica or aerogel are good candidates for this purpose. However, the native nanostructure of silica has never been imaged or characterized up to now, making SIM optimization quite difficult. In this paper, three nanostructured commercial silica samples prepared by different synthesis methods were analysed and quantified using advanced electron tomography, N 2 physisorption, mercury porosimetry and helium pycnometry. It was demonstrated that 3D images yield a much finer description of the microstructure (particle, aggregate and pore) compared to global measurements. For the samples studied, silica particle size is dependent on the synthesis method, increasing with pore diameter size. The smallest silica particles were obtained by the sol-gel method which also provides the smallest pore diameters, the smallest and rather spherical aggregates, and the lowest thermal conductivity. The pyrogenic and precipitated samples studied presented bigger silica particles with higher pore diameters and thus higher thermal conductivities. 3Dimage driven characterization opens up new synthesis opportunities for silica.

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Section: -23mentioning

confidence: 99%