What Is Supercritical Drying?
Supercritical drying is a method of drying porous materials. Can be combined with sol-gel method to prepare nanoporous materials.
Supercritical drying
discuss
- Chinese name
- Supercritical drying
- Foreign name
- supercritical drying
- Supercritical drying is a method of drying porous materials. Can be combined with sol-gel method to prepare nanoporous materials.
- Due to the surface tension of the solvent inside the gel framework, the framework will collapse under ordinary drying conditions. The purpose of supercritical drying is to control the pressure and temperature so that the solvent reaches its own critical point during the drying process to complete the liquid phase to supercritical fluid transition. During the process, the solvent has no obvious surface tension, and the transition from wet gel to aerogel is completed while maintaining the framework structure. The apparatus used for supercritical drying is an autoclave, and the tightness of the autoclave is high. Generally, the supercritical drying process requires a relatively long experimental period, a low yield, and a high cost, and is used to prepare more stringent products.
- The basic principle of supercritical drying is: in the supercritical state, there is no longer an interface between gas and liquid, but it becomes a uniform fluid between gas and liquid. This fluid is gradually discharged from the gel. Because there is no air-liquid interface, there is no capillary force, so it will not cause the gel to shrink and destroy the structure until all the fluid is discharged from the gel. A gas-filled material with a nanopore structure was obtained [1] .