Aggregation of ionic surfactants in formamide

Electrical conductivity and surface tension measurements of various ionic surfactants, such as sodium caprylate, sodium laurate, sodium palmitate and sodium stearate, in formamide has been determined at 22 degrees C. Both methods show that micelles are formed in formamide solution. Critical micelle concentration (c.m.c.) has been determined for each of the ionic surfactants. It is suggested that amphiphilic self-assembly is a physical process that occurs in formamide and the driving force for aggregation correlates with solvophobicity. The surfactant-solvent interactions that drive amphiphilic self-organization in formamide are discussed. Thermodynamic parameters were evaluated for micellar systems to explain the results. (C) 2000 Elsevier Science B.V. All rights reserved.