Ahelsilikaadid

Ahelsilikaadid, also known as silica aerogels, are a class of highly porous, ultralight materials composed primarily of silicon dioxide (SiO2) with a high degree of porosity. They are characterized by their extremely low density, typically ranging from 1.9 to 3.0 kg/m³, which is about one-thousandth the density of glass. This low density is achieved through a process called supercritical drying, which replaces the liquid component of a gel with gas without causing collapse of the gel's structure.

Ahelsilikaadid possess unique thermal properties, including excellent thermal insulation. Their low thermal conductivity, typically around 0.013 W/(m·K), makes them highly effective at resisting heat transfer. This property is due to the high porosity and the low density of the material, which minimizes the amount of solid material that can conduct heat.

Due to their thermal insulation properties, ahelsilikaadid are used in various applications, including building insulation, aerospace, and electronics. They are also being explored for their potential in energy storage and conversion technologies. However, their high cost and fragility are significant challenges that limit their widespread use.

The production of ahelsilikaadid involves several steps, including the synthesis of a silica sol, the formation of a silica gel, and the supercritical drying process. The sol-gel process is commonly used to create the silica gel, which is then dried using supercritical carbon dioxide to preserve the gel's porous structure.