Ultrasound in Interface Tension Measurement

V.B.Akopyan (Protein Biosynthesis Institute, Moscow, Russia)

e-mail: akopyan@edunet.ru

A lot of different techniques of the surface and interfacial tension measurement are used in the basic researches and for solving a number of practical problems. Almost every method is based on the interaction of the liquid surface (or liquid-liquid interface) with a foreign solid body surface. The use of ultrasound allows measuring the surface (interfacial) tension in the absence of foreign bodys, low interfacial tension between two liquids etc. The method is based on the well-known effect of button appearance in the surface of liquid (or liquid-liquid interface) caused by radiation pressure. The direction of convexity not always coincides with the direction of ultrasonic wave propagation and depends on the difference between the energy densities at both sides of the interface1. The measurement is convenient to realise by using the deviation of a light ray reflected from the deformed interface. 1. Hertz G., Mende H., Der Schallstrahlungsdruck in Flussigkeiten, Zs. f. Phys., 1939, 114, p.354.


Section : 11