Living Reference Work Entry

Handbook of Sol-Gel Science and Technology

pp 1-21

Date: Latest Version

Aerogel Sintering: From Optical Glasses to Nuclear Waste Containment

  • J. PhalippouAffiliated withLaboratoire Charles Coulomb
  • , P. DieudonnéAffiliated withLaboratoire Charles Coulomb
  • , A. FaivreAffiliated withLaboratoire Charles Coulomb
  • , Thierry WoignierAffiliated withIMBE, CNRS, IRD, Aix Marseille UniversitéAix Marseille Université, CNRS, IRD, Avignon Université, UMR CNRS 7263, Institut Méditerranéen de Biodiversité et d’Ecologie marine et continentale (IMBE) Email author 

Abstract

Aerogels are ultraporous materials with a very low permeability. They exhibit high specific surface area but, due to their huge porous volume, their mechanical properties are quite poor. Aerogels belong to two main families: inorganic materials as silica, silicates, and a few aluminates and organic aerogels which are easily transformed into carbon aerogels by a simple pyrolysis thermal treatment. In this chapter, we mainly report experiments performed on alcohol-dried aerogels. Due to their broad range of porosity, aerogels can fit in very different applications: from analysis of cosmic dust to nuclear waste containment glasses. Advantages of large porosity are sometimes used directly like in thermal and acoustic insulation, or in catalyzers, but a too high pore volume can also be a drawback like in glass precursor and host matrix. Fortunately, aerogel porosity can be tailored using sintering or room isostatic compression or eventually a combination of both methods. Knowledge in this area allows now to synthesize aerogels with a broad range of porosity and also a very broad range of texture.