Hydrophobic hydration and CMC

Abstract

One of the most important problems of the physical chemistry of surfactant — the nature of the hydrophobic effect is examined here. Usually this effect is explained by means of iceberg formation around the hydrocarbon groups of surfactant in water. Therefore, it is interesting to know the type of the hydration of the surfactant ions.

In this work parameters of the hydration are calculated from data containing electroconductivity of the surfactant aqueous solutions. Measuring of electroconductivity is carried out in a broad region of temperatures (15–50)°C and concentrations (0.1–8 mM1⁻¹). Experiments and calculations show that the surfactant ions may condense or brake the structure of water as in the case of the nonorganic ions.

The type of the hydration may influence the value of the CMC.