A material that helps suspend one liquid in another with which it would not mix otherwise.

a material that causes water and oil to form an emulsion. Water normally occurs separately from oil; if, however, an emulsifying agent is present, the water becomes dispersed in the oil as tiny droplets. Or, rarely, the oil may be dispersed in the water. In either case, the emulsion must be treated to separate the water and the oil.

a chemical similar to soap which helps oil and water to mix and form an emulsion

An active agent which reduces the surface stresses of a fluid in order to take up another fluid in a finely distributed form.