Supercritical drying chamber for aerogel production

2011-10-28

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I built a pressure chamber from 2" pipe fittings and 1/8" brass valves to contain supercritical CO2 for drying applications. One project is to try aerogel production which generally requires that solvent be removed via supercritical drying. Normal evaporation would deform the aerogel structure as the surface tension of the solvent pulls the gel's structure tighter together and makes it dense. Since supercritical fluids have gaseous properties, they can diffuse out through the gel without affecting the structure the way that a liquid would.