Surfactant order to manipulate growth. and assembly of the dots, reactions on their surface, electrical properties, etc., it is important to understand how surfactants arrange on the surface of the quantum dots. Surfactant Surfactants are compounds that lower the surface tension (or interfacial tension) between two liquids, between a gas and a liquid, or between a liquid and a solid. Surfactants may act as detergents, wetting agents, emulsifiers, foaming agents, and dispersants. The term "surfactant" is a blend of "surface active agent". In the United States National Library of Medicine's Medical Subject Headings (MeSH) vocabulary, "surfactant" is reserved for the meaning
Goniometer and is better suited for dynamic and advanced studies. Contact angle goniometers (q.v.)can also determine the surface tension for any liquid in gas or the interfacial tension between any two liquids. If the difference in densities between the two fluids is known, the surface tension or interfacial tension can be calculated by using the pendant drop method. An advanced instrument often called a goniometer / tensiometer will include software tools to measure surface tension and interfacial tension using the pendant drop, inverted pendant drop, and sessile drop methods - in addition to contact angle. A centrifugal adhesion balance is used