This property makes them essential in many industrial applications and also in everyday life. For example, mayonnaise is a stable emulsion of water and oil thanks to the surfactant contained in the egg yolk!
They therefore have an affinity for both oil and water. This unique, remarkable property enables them to solubilise two initially immiscible phases.
Dissolved in water, the surfactants gather at the interfaces, orienting themselves so that the hydrophilic part of their molecule is directed towards the water and the hydrophobic part towards the oily phase or the air.