It is normally expected in substances that, if originally at room temperature and in a solid state; and if the temperature were to increase, they will pass into the liquid state. If they are in a liquid state and the temperature increases, then you would expect them to go into a gaseous state. However, there are certain substances that go directly from the solid state to the gaseous state, which is known as sublimation.

Sublimation occurs when under certain pressure conditions, there is no temperature at which the liquid phase is possible. That is, sublimation occurs when the gas phase is more stable than the liquid phase, so when the temperature increases, the system originally in the solid state does not pass through the liquid phase but goes directly to the gas phase. When this phenomenon occurs, then the solid is said to sublime. It should be noted that sublimation is unique and unique to the solid state, by definition there can be no liquid that sublimates. This is because the transformation requires you to go from a solid to a gas.

Without involving changes in pressure, there are some substances that sublimate naturally. A classic example of substances that sublimate are those substances that give off an intense aroma very easily. Cinnamon is an example of these substances. What we are perceiving is nothing more than cinnamon molecules that escape from the cinnamon sticks or powder that are in a solid state and reach our nose in a gaseous state.

Dry ice is an example of a substance capable of sublimation. The purification of sulfur and iodine also involves a sublimation process. Vapor or saturation pressure is the pressure at which, at a given temperature, the solid (or liquid) phase and the vapor phase reach a dynamic equilibrium or harmony.

Psychology, for its part, speaks of sublimation to name a defense mechanism that consists of replacing the individual’s instinctive object of desire with another object, which loses its sexual charge as it passes through consciousness.

In this area it is necessary to emphasize that the father of this terminology was the Austrian physician and neurologist Sigmund Freud, also considered the father of psychoanalysis. This character extensively developed and explained the aforementioned sublimation in a large number of scientific works, such as the case of the work entitled “Cultural sexual morality and modern nervousness.”