Interfacial Tension of Aqueous Surfactant Solutions by the Pendant Drop Method

The low interfacial tensions between two liquids have been measured for different systems by using the pendant drop method. In the case of the quaternary system: C 12 H 25 SO 4 Na+H 2 O+n-Butanol+Toluene, the interfacial data as measured by pendant drop method are compared with reported literature data, using other methods (with varying NaCl concentration). In order to understand the role of co-surfactant, ternary systems were also investigated. The pendant drop method was also used for measuring the interfacial tension between surfactant-H 2 O/n-alcohol (with number of carbon atoms in alcohol varying from 4-10). The interfacial tension variation was dependent on both the surfactant and alcohol.