It is called interface tension
Interfacial tension is defined as the tendency where an interface becomes spherical to make its surface energy as low as possible.
Interfacial tension plays an important role in different processes and they are:
- Emulsions and emulsifiability
- Quality testing of hydrophobic liquids
- Solid-liquid phase gets affected by the interfacial tension on a long-term
Difference between surface tension and interfacial tension.
Surface tension is defined as the amount of energy which is required for increasing the surface area between the liquid and gas. Whereas interfacial tension is defined as the amount of energy which is required to increase the interfacial area between the two immiscible liquids.