Friday, October 17, 2014

Hair Styling Tips -- How to Make Hair Curly or Straight

What Makes Hair Naturally Curly
According to researchers who have been studying how certain chemical react with hair, the main reason some people's hair are naturally curlier than others, is simply because their hair have more disulfide bonds (2 sulfur atoms linked to each other to form a bond).
Structure of a Disulfide Bond
The proteins in hair known as keratin, contain amino acids called cysteines; and disulfide bonds connect cysteines to each other. The more disulfide bonds, a person’s hair contains, the curlier it will be.  Although all hair has disulfide bonds, it is the shape of the hair strand itself which determines the number of these bonds and in what way they are organized.

The bottom line is however, people with straight hair can make their hair curly, and those with curly hair can make their hair straight by using a perm or a relaxer.

Relaxers versus Perms
Based on research we can change whether or not hair is curly or straight by changing the disulfide bonds. Relaxers simply break these disulfide bonds and cap them so that they cannot chemically reform. Classically, hair relaxers use a reducer or a base (the opposite of an acid) such as Lye(sodium hydroxide) to break and cap these bonds. Disulfide bonds are not affected by water so, when you break the bonds and cap them (in the case of relaxers) they will not go back to their original state.

Perms which purposely curl hair, chemically increase the number of disulfide bonds by using an oxidizer to uncap the naturally caped sulfides in straight hair. As the name implies, these perms will stay "forever" curly. So, as you can see, one chemical (a reducer) can make your hair straight, while another chemical (an oxidizer) can make your hair curly.

Cornell Center for material Research