Surfactants are materials that lower the surface tension (or interfacial tension) between two liquids or between a liquid and a solid. Based upon the composition of the polarity of the head group, there are 4 types of surfactants, nonionic, anionic, cationic, amphoteric. A natural surfactant has to have both the head and tail groups to come from truly natural sources. Natural surfactants can be derived from many types of plants. Common sources are coconut or palm, but they can also be derived from other types of fruits and vegetables. 5 plant-derived non-ionic surfactants are as follows:
Coco Glucoside: Coco glucoside is a non-ionic natural surfactant with an alkaline pH around 12. It is a gentle foamy cleanser derived from coconut oil and fruit sugars and is completely biodegradable.
Decyl Glucoside: Decyl glucoside is also obtained from coconut oil and glucose and is completely biodegradable. It is similar to Coco Glucoside except that it has a shorter chain length and creates less foam. The foam that is created is less stable.
Lauryl Glucoside: Lauryl glucoside is similar to Coco glucoside and Decyl glucoside but with a longer chain. It is also more viscous. Lauryl Glucoside takes the longest to foam but the form that is created is also the most stable.
Coco Betaine: Coco betaine is a mild, coconut-based amphoteric surfactant with a pH around 6-8. It is completely biodegradable and increases the form and viscosity of products to which it is added.
Disodium Laureth Sulfosuccinate: Disodium laureth sulfosuccinate is a gentle anionic surfactant. Its larger molecules are unable to penetrate and irritate the skin, making it the preferred choice for use in products formulated for sensitive skin