Interfacial Pressure (π) Exerted by Sodium Dodecyl Sulphate (NaDS) at Oil Water Interface.

Equations proposed by Ghosh³ and by Davies¹ to account for the relationship between π and A at oil/water interface have been discussed critically with the help of the data obtained by us on the interfacial pressure exerted by NaDS at a number of oil/water interfaces. There is hardly any difference in the values of π calculated from the equation of Davies and the equation of Ghosh. The values of π calculated from both the equations agree well with those found experimentally only over a certain range of concentration of NaDS investigated.