Surfactants & adsorbtion A.K.A. how to impress people at parties PART I

Surfactants? Adsorption? Do I mean surfectants and absorption? No, I do not.

Ahem (cue scholarly voice), there are some hair terms you may want to wrap your head around.

Surfactant (from Wikipedia): "Surfactants are compounds that lower the surface tension (or interfacial tension) between two liquids or between a liquid and a solid. Surfactants may act as detergents, wetting agents, emulsifiers, foaming agents, and dispersants."

Surfactants, essentially, help get your hair clean. If you want to know more, read on!



There are three main types of surfactants:

1. Anionic: most of the well known surfactants are in this category. Most sulfates (i.e. Sodium Lauryl Sulfate, Sodium Laureth Sulfate, Ammonium Lauryl Sulfate etc.) are in this category, as well as their common replacements in "sulfate free" shampoos, like Sodium Myreth Sulfate and Sodium Laroyl Sarcosinate.

2. Zwitterionic: theses are very gentle, but they are seldom used alone as they are not particularly effective by themselves. A famous one would be Cocamidopropyl betaine.

3. Non ionic: there are many types of non ionic surfactants, but the ones you see most often in natural products are Cocamide MEA and the glucosides i.e. Decyl glucoside, Lauryl glucoside and Octyl glucoside.

Here is a really great post from the Natural Haven about surfactants, and here is another great post from the Natural Haven about surfactants in common sulfate free shampoos.

If it's been a while since you took a chemistry class, do not fear. Just learning a little about Ph (remember the litmus strips?) and how cleansers work can really help when choosing what shampoo is best for you. The internet does not judge (at least to my knowledge. I do sometimes get the sneaking suspicion that Google is mocking me.......).


What else does Wikipedia say, you ask? Well, "Surfactants are usually organic compounds that are amphiphilic, meaning they contain both hydrophobic groups (their tails) and hydrophilic groups (their heads). Therefore, a surfactant contains both a water insoluble (or oil soluble) component and a water soluble component. Surfactants will diffuse in water and adsorb at interfaces between air and water or at the interface between oil and water, in the case where water is mixed with oil."

What is adsorb? I thought you'd never ask. Continued, in part II!