How Hair Conditioner Works

2 Conversations


The first thing you need to know about is the structure of hair. Hair, as you may know, is composed of a protein called keratin. This fact is important because keratin has a high percentage of those amino acids which have negative charges sticking out, like the hairs on a nettle.


The next thing you need to know is that most hair conditioners contain positively charged molecules called cationic surfactants. Soap, shampoo, and other cleaners contain surfactants (also called detergents) that are anionic, that is, negatively charged. These cleaners are very effective at removing dirt, but they also remove natural oils and positive charges from the hair.


The positively charged surfactants in hair conditioner are attracted to the negative charges in your hair, and do not rinse out completely with water. When the hair dries, it is coated with a thin film, which adds weight, makes the hair easier to comb, and prevent static electricity from building up and "frizzing" the hair.


Static buildup, by the way, is what happens when the positive charges are stripped from the hair. Rubber combs do this very nicely, which is why combing your hair on a dry day makes the hair "frizz out"; the negative charges on your hair are repelling each other!


All surfactants comprise an "oily part" and a "watery part". The watery part (called the "hydrophile") is what sticks to the hair; it contains the positive charge. The oily part (called the "hydrophobe") is what gives the surfactant its conditioning ability, as it smooths the hair and gives it weight. The cationic surfactants used in conditioners come in several types, and can be classified by the nature of their hydrophobes.


If the hydrophobe has the structure of a saturated fat (like lard or butter), the surfactant has a waxy consistency. Oily hydrophobes, with a structure like liquid vegetable oil, give the surfactant a lighter texture; they may even be liquids. Hydrophobic polymers yield a hard, plastic-like material.


Hair conditioners come in several different types. "Pack" conditioners are heavy and creamy in consistency. They contain high percentages of "fatty" surfactants, and are used when the hair is damaged. Such conditioners are left in the hair for a long time, and will virtually "glue" split ends and stripped scales into place. "Leave-in" conditioners are lightweight, and will contain lighter-weight "oily" surfactants, which add little weight to the hair. Ordinary conditioners have a balance between the two. There are also "hold" conditioners, combination products which provide the benefits of conditioning while also holding the hair in place like a mousse. This effect is achieved using cationic polymers.


Finally, there are some conditioning ingredients which are not cationic. These do not offer the best results, but they have benefits of their own. Some anionic surfactants, which carry no electric charge, will stick to the hair in useful quantities. Unlike cationic surfactants, they can be mixed with anionic surfactants to produce conditioning shampoos. Other ingredients, like esters, oils, and polymers, are added to improve luster, add combability, and assure that the conditioning ingredients stay mixed in the bottle.

Bookmark on your Personal Space


Entry

A526484

Infinite Improbability Drive

Infinite Improbability Drive

Read a random Edited Entry


Written and Edited by

Disclaimer

h2g2 is created by h2g2's users, who are members of the public. The views expressed are theirs and unless specifically stated are not those of the Not Panicking Ltd. Unlike Edited Entries, Entries have not been checked by an Editor. If you consider any Entry to be in breach of the site's House Rules, please register a complaint. For any other comments, please visit the Feedback page.

Write an Entry

"The Hitchhiker's Guide to the Galaxy is a wholly remarkable book. It has been compiled and recompiled many times and under many different editorships. It contains contributions from countless numbers of travellers and researchers."

Write an entry
Read more