Emulsification

In detail

Water and oil do not mix because water molecules are polar and attract each other strongly, while oils are not and are excluded. Emulsification is the process of getting oil to travel in water anyway, by breaking it into droplets small enough to stay suspended and wrapping each one in surfactant molecules whose oil-loving tails point inward and whose water-loving heads point out. The droplet is then, as far as the water is concerned, a water-friendly particle, and it can be carried away. Two consequences follow that explain a great deal of practical cleaning. The grease is suspended rather than destroyed, so it goes down the drain with the rinse water — and if the rinse is inadequate, the emulsion breaks as the water evaporates and the oil is redeposited, which is why an under-rinsed surface feels greasy again once dry. And emulsification is why mechanical action helps: agitation is what breaks the oil into droplets in the first place, and heat helps by lowering the oil's viscosity so it divides more readily. A detergent with no agitation and no rinse is doing a third of the job.

Why

• Linear alkylbenzene sulphonate is explained by Emulsification
• Makeup is explained by Emulsification
• Grease is explained by Emulsification
• Two-stage degreasing is explained by Emulsification
• Cresol disinfectant is explained by Emulsification

  Barely soluble in water, so it was sold emulsified with soap. That is why it turns milky in the bucket.