What is the Most Diffuse Solid?
The most diffuse solids are the aerogels, created by subjecting a conventional gel to supercritical drying. Supercritical drying allows the liquid to be extracted from the gel without collapsing the gel’s matrix due to capillary action. Supercritical drying requires a high temperature (705 °F, 374 °C) and pressure (219 atmospheres). It forces the liquid to enter a state indistinguishable from a gas or liquid (a supercritical liquid), then heats it up and causes it to transform into a gas. The capillary action is prevented by avoiding a direct liquid-to-gas transition, as in evaporation. Aerogel was invented by Steven Kistler in 1931, allegedly as part of a bet with his friend to see who could extract the liquid from jam while still preserving its volume. Aerogels is a remarkable material. Nicknamed “frozen smoke” for its appearance, aerogel is extremely diffuse, made of 99.8% air. Its density is only 3 milligrams per cubic centimeter (3 kg per cubic meter), 0.3% the density of water.
The most diffuse solids are the aerogels, created by subjecting a conventional gel to supercritical drying. Supercritical drying allows the liquid to be extracted from the gel without collapsing the gel’s matrix due to capillary action. Supercritical drying requires a high temperature (705 °F, 374 °C) and pressure (219 atmospheres). It forces the liquid to enter a state indistinguishable from a gas or liquid (a supercritical liquid), then heats it up and causes it to transform into a gas. The capillary action is prevented by avoiding a direct liquid-to-gas transition, as in evaporation. Aerogel was invented by Steven Kistler in 1931, allegedly as part of a bet with his friend to see who could extract the liquid from jam while still preserving its volume. Aerogels is a remarkable material. Nicknamed “frozen smoke” for its appearance, aerogel is extremely diffuse, made of 99.8% air. Its density is only 3 milligrams per cubic centimeter (3 kg per cubic meter), 0.3% the density of water. A
