​​How does Soap and Detergent work?

Soaps and detergents are made from long molecules that contain a head and tail. These molecules are called surfactants; the diagram below represents a surfactant molecule.

The head of the molecule is attracted to water (hydrophilic) and the tail is attracted to grease and dirt (hydrophobic). When the detergent molecules meet grease on clothes, the tails are drawn into the grease but the heads still sit in the water.

The attractive forces between the head groups and the water are so strong that the grease is lifted away from the surface. The blob of grease is now completely surrounded by detergent molecules and is broken into smaller pieces which are washed away by the water.

The detergent molecules also help to make the washing process more effective by reducing the surface tension of the water. Surface tension is the force which helps a blob of water on a surface hold its shape and not spread out. The attractant molecules of the detergent break apart these forces and make water behave, well, wetter!

#yuvraj #detergent