1. The interfacial tension against water at 20 �C is 8.97 mN / m. 2. Surfactants reduce the interfacial tension between oil and water by adsorbing at the liquid liquid interface. 3. It is desired that the surfactant will work at the lowest interfacial tension ( IFT ). 4. The force at equilibrium can then be used to determine the absolute surface or interfacial tension . 5. Below the CMC point, interfacial tension between oil and water phase is no longer effectively reduced. 6. As the interfacial tension increases, the net magnitude decreases due to an increase in capillary forces. 7. It refers to either using the fluids with low interfacial tension or working at very high angular velocities. 8. This method is widely used in many different applications such as measuring the interfacial tension of polymer blends and copolymers. 9. This empirical observation can be rationalised by considering the interfacial tension at the oil-surfactant and water-surfactant interfaces. 10. One disadvantage of this technique is that it can not bury the rod into the surface to measure interfacial tension between two liquids.
