Wetting agents are substances that reduce the surface tension of water to allow it to spread drops onto a surface, increasing the spreading abilities of a liquid. Lowering the surface tension lowers the energy required to spread drops onto a film, thus weakening the cohesive properties of the liquid and strengthening its adhesive properties. The simplest way to improve water take up by hydrophobic soils is to use a soil wetting agent. When organic matter on the soil breaks down it leaves a waxy coating on the soil particles. Wetting agents are like detergents. They overcome that waxing coating and allow water to penetrate into the pore spaces between. There are four main types of wetting agents: anionic, cationic, amphoteric, and nonionic.
- Wide range of application such as in Plant growth regulation, Herbicides, Pesticides, Antiseptics, Fertilizers and trace elements. One example of how wetting agents work is in the formation of micelles. Micelles consist of hydrophilic heads forming an outer layer around lipophilic tails. When in water, the micelles' tails can surround an oil droplet while the heads are attracted to the water.