Monolithic ceramics aerogels

The sol-gel process involves the transition of a system from a liquid "sol" (mostly colloidal) into a solid "gel" phase (11). By applying this methodology, it is possible to fabricate ceramic or glass materials in a wide variety of forms ultrafine or spherical-shaped powders, thin film coatings, ceramic fibers, microporous inorganic membranes, monolithic ceramics and glasses, or extremely porous aerogel materials. 

Prassas M, Phalippou J, Zarzycki J (1986) Sintering of monolithic silica aerogels. In Hench LL and Ulrich DR (eds) Science of Ceramic Chemical Processing, WUey, New York... 

Wei, T, Chang, T, Lu, S, Chang, Y (2007) Preparation of monolithic silica aerogel of low thermal conductivity by ambient pressure drying. J Am Ceram Soc 90(7) 2003-2007. 

TiUotson T.M., Hrubesh L.W. Transparent ultralow-density silica aerogels prepared by a two-step sol-gel process. J. Non-Gyst. Solids 1992 145 44-50 Wang J., Kuhn J., Lu X. Monolithic silica aerogel insulation doped with Ti02 powder and ceramic fibers. J. Non-Cryst. Solids 1995 186 285-290... 

J. Zarzycki, Monolithic xero- and aerogels for gel-glass processes, in L.L. Hench and D.R. Uhlrich (Eds.), Ultra Structure Processing of Ceramics, Glasses and Composites. Wiley, New York, 1984, pp. 27-43. 

Very recently, hierarchically arranged aerogel monoliths [209], silica-based monoliths from swollen liquid crystals [210] or heptane/water/ethanol/sodium dodecylsulfate microemulsion [211], monolith-based hybrid components such as the PMOs [212], and silicon oxycarbide monoliths with better thermal properties than the pure (organo) silica monoliths [213] have been reported. These approaches have been extended also to alumina or aluminumsilicates [214, 215], titania [216, 217], zirconia [218], or ceramic-based [219] systems. 

Zarzycki, J., Monolithic xero and aerogels for ge1-g1ass process. In Ultrastructure Processing of Ceramics, Glasses and Composites Hench, L.L. and Ulrich, D.R. (Eds), Wiley (1984). 

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