Surfactant

The word surfactant comes from the English surfactant. It's actually an acronym for the phrase surface active agent. It's also called tenside. Any substance that adds a small amount and can significantly reduce the surface tension of the liquid is collectively referred to as a surfactant. Their surface activity is for a specific liquid, usually water. One end of the surfactant is a non-polar hydrocarbon chain (hydrocarbon group), which has very little affinity with water and is often called hydrophobic group; On the other end is a polar group (such as -OH, -COOh, -NH ₂, -SO₃ H, etc.), which has a great affinity with water, SO it is called a hydrophilic group, and is generally called "parent molecules" (oleophilic hydrophilic molecules).