superkriitilises

Superkriitiline refers to a state of matter that exists for a pure substance when it is above its critical temperature and critical pressure. In this superkriitiline state, the substance has properties of both a liquid and a gas. It is a single phase, with no distinction between liquid and gas.

The critical point is the specific temperature and pressure at which the liquid and gas phases of a substance become indistinguishable. Above this point, increasing pressure does not cause the substance to liquefy, and increasing temperature does not cause it to vaporize. Instead, the substance becomes a superkriitiline fluid.

Superkriitiline fluids possess unique characteristics. They can diffuse through solids like a gas, allowing for penetration into porous materials. They also have a solvating power comparable to liquids, meaning they can dissolve substances. By adjusting the pressure and temperature of a superkriitiline fluid, its density and solvating power can be finely tuned, making them versatile solvents.

One of the most common superkriitiline fluids is superkriitiline carbon dioxide (scCO2). Due to its low critical point (31.1 °C and 73.8 bar), it is widely used in various applications. These include decaffeination of coffee and tea, extraction of essential oils and flavors, dry cleaning, and in chromatography for analytical purposes. Other substances, like water and some organic solvents, can also form superkriitiline fluids, each with its own specific critical parameters and applications.