Why does moisture make your hair upset?

You have probably heard someone say that when it rains, their hair becomes unmanageable. It is a fact: straight hair, when exposed to moisture, tends to become wavy, while frizzy hair gets more frizz or even more curls.

The question is, why does this happen? First of all you need to know that human hair is extremely sensitive to moisture, so much so that some monitoring stations use the hair as a measuring mechanism, as it changes its length according to the air to which it is exposed and according to the amount of moisture. hydrogen present in the atmosphere.

It's all about chemistry

The capillary structure is made up of keratin proteins, which chemically speak in two different ways. In the first case, they can form a disulfide bond, in which two sulfur atoms are covalently bonded together and give the hair more strength, so that it is not affected by air humidity.

Another possible type of connection is formed only by a hydrogen bond, which disfavors the strength of the capillary structure, making the hair weaker. In these cases, hydrogen bonds break down whenever the hair gets damp and then dries.

These bonds occur when keratin molecules form a weak attraction to water molecules present in moisture, which causes two keratin proteins to join together. Since moist air has more water molecules than dry air, a single strand of hair can produce multiple hydrogen bonds, and when many of them are composed, the strands of hair come out of shape and undergo small folds and lifts, or ie frizzy or wavy.

* Posted on 24/04/2013