szublimációként

Sublimation is a chemical process where a substance transitions directly from the solid to the gas phase without passing through the liquid phase. This occurs when the vapor pressure of the solid equals the surrounding pressure. Common examples include dry ice (solid carbon dioxide) and iodine. When dry ice is exposed to room temperature, it does not melt into liquid carbon dioxide; instead, it turns directly into gaseous carbon dioxide. Similarly, solid iodine crystals, when heated, produce purple iodine vapor. The temperature at which sublimation occurs is known as the sublimation point, which is dependent on the substance and the surrounding pressure. This phenomenon is utilized in various applications, such as freeze-drying, where water is removed from food or biological samples by sublimation under vacuum, preserving their structure and properties. It is also employed in purification techniques and in certain printing processes like sublimation printing, where dyes are converted into gas and then absorbed by a substrate. The reverse process, where a gas directly transforms into a solid, is called deposition or desublimation.