X-Message-Number: 6305 Date: Mon, 3 Jun 1996 05:51:29 -0700 (PDT) From: Doug Skrecky <> Subject: Xerogel Vacuum Insulation A new solid xerogel vacuum insulation is in development at Dow Chemical Company. Xerogels are microcellular solids prepared from a non-supercritical evaporation of solvents from a solvent/polymer gel. They are potentially less expensive than aerogels since the later requires more expensive supercritical evaporation. Xerogels are somewhat denser than aerogels since surface tension causes some shrinkage during drying. Under a soft vacuum xerogels have a higher conductivity than silica vacuum powder insulation, but below 1.5 torr have a slightly lower conductivity. Xerogels are a potential replacement for vacuum powders since their monolithic form might reduce the cost of building vacuum insulation panels. Reference: "Microcellular Polyurea Xerogels for Use in Vacuum Panels" Journal of Cellular Plastics Vol.32 172-190 March 1996 For more information contact: Rick L. Tabor The Dow Chemical Company Polyurethanes Products Research Laboratory Building B-1608 Freeport, TX 77541 Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=6305