Full Article:

The Pendant drop tensiometry offers a simple solution to determining surface and interfacial tension. The droplet pendant method is based on determining the profile of a droplet of a liquid with higher density than the other of lower density in mechanical equilibrium. However, to ensure the reliability of the data it is necessary to realize a preliminary study of the volume and interfacial area of the droplet formed. In this work, the influence of the droplet volume, in a system with petroleum and sodium sulfate in deionized water, was studied. It was shown that the variation of the droplet volume is independent of the droplet volume, but in order that the droplet does not stand out during the interfacial film ageing time, it was necessary to use a volume of 80%.