süblimasyon

Sublimation is a chemical process where a substance transitions directly from the solid to the gas phase without passing through the liquid phase. This phenomenon occurs at a specific temperature and pressure, known as the sublimation point. Dry ice, which is solid carbon dioxide, is a common example of a substance that sublimes at room temperature and standard atmospheric pressure. Instead of melting into liquid, it turns directly into gaseous carbon dioxide.

The reverse process, where a gas transitions directly into a solid without becoming a liquid, is called deposition or desublimation. This can be observed when frost forms on a cold window pane, as water vapor in the air turns directly into ice crystals. The energy required for sublimation is known as the enthalpy of sublimation. This energy is equal to the sum of the enthalpy of fusion (solid to liquid) and the enthalpy of vaporization (liquid to gas).

Sublimation has various practical applications. In industry, it is used for purification processes, such as purifying iodine or separating mixtures. In laboratories, freeze-drying, a technique used to preserve food or biological samples, relies on sublimation to remove water as ice vapor under vacuum. The ability of some substances to sublimate is also utilized in sublimation printing, a popular method for transferring dyes onto synthetic fabrics and other materials using heat.