When there is dirt on the clothes we wear or use, it will have a certain binding force with the clothes and will not be easily removed automatically. At this time, it needs to be removed by washing. The washing medium is usually water. If the dirt is water-soluble, it can be decontaminated by repeated washing with a large amount of water, but many dirts are oily. agent) to remove them. When we soak the soiled dirty clothes in the washing liquid, the hydrophobic (lipophilic) part of the surfactant is easy to adhere to the dirt or greasy, while the hydrophilic part is oriented towards the water phase, so that the original is not easily absorbed The surface of the soiled fiber wetted by water becomes easily wetted by water. Synthetic detergent adsorbed to fibers and dirt also reduces the surface tension of water, causing fibers and dirt to expand due to the generation of a large number of air bubbles, allowing the washing liquid to further penetrate into it. With appropriate mechanical force, such as hand rubbing, or agitating with a washing machine pulsator, those loose dirt particles will be dispersed and shed into the water. This is the decontamination principle of common synthetic detergents.
