Lately I have been getting a wee bit technical, which is important if you want to know how lovely surfactants create all that foam.
In cosmetic chemistry, soap surfactants are known as surface active ingredients, they all work on the same basic principle – that everything in nature is either water loving or oil loving.
These surfactants are made up of long molecules and each end of these molecule plays a different role:
- Hydrophilic, which means that they are water loving
- The Lipophilic molecule is oil loving
- Hydrophobic meaning it repels water
Understanding surfactant surface tension
So, what exactly does surfactant surface tension really mean? In layman’s terms, if you look at the structure of a shower gel, the dirt and oils from the skin stick to the lipophilic end, they are lifted off the skin and washed away by the hydrophilic end of the molecule.
From a slightly more technical view point, hydrophilic substances easily dissolve in water, the lipophilic substances easily dissolve in hydrocarbons – the essential organic compounds of carbon and hydrogen, it is these hydrocarbons that have an affinity with oil and dirt.
The usual job of detergents is to make lipophilic substances like oils, fats and grease are soluble in water, so they can be easily washed off the skin. The lipophilic end of the molecule the hydro carbons literally bury themselves into the grease, when enough of the molecules embed their hydrocarbon ends into the oil and dirt, the surrounding water molecules that are attracted to the part of the molecule that likes water, breaks down the dirt and oils into tiny little pieces. This action causes it to separate and dissolve, carrying away the grease.
So, as you can see, the role of surfactants on the skin is extremely interesting and if you’d like to find out more about our relationship with lovely foam, follow the link to find out more.