sublimaatioihin

Sublimaatioihin, commonly translated as sublimation, is a phenomenon in chemistry and physics where a substance transitions directly from a solid to a gas state without passing through the liquid phase. This process is the reverse of deposition, where a gas directly turns into a solid. Sublimation occurs when the vapor pressure of a solid exceeds the ambient pressure.

The temperature at which sublimation occurs is known as the sublimation point. This point is dependent on the specific substance and the surrounding atmospheric pressure. For example, dry ice, which is solid carbon dioxide, sublimes at atmospheric pressure at -78.5 degrees Celsius. Iodine is another common substance that readily sublimes at room temperature, forming a purple vapor. The process of sublimation is endothermic, meaning it requires energy to occur. This energy is absorbed from the surroundings, causing a cooling effect.

Sublimation has various practical applications. It is used in freeze-drying (lyophilization), where water is removed from a substance by freezing it and then reducing the surrounding pressure to allow the frozen water to sublimate directly from ice to water vapor. This method is used to preserve food, pharmaceuticals, and biological samples. In purification, sublimation can be used to separate volatile solids from non-volatile impurities. The impure solid is heated, the desired component sublimes, and then it is collected as a purer solid on a cooled surface. In art and printing, sublimation printing uses heat to transfer dye onto materials. The dye turns into a gas and permeates the fibers of the material, creating a durable and vibrant image.