Conductance and surface tension of ionic surfactants in molten acetamide

Electrical conductivity and surface tension measurements on various surfactants, such as sodium caprylate, sodium laurate, sodium palmitate, sodium stearate, sodium oleate, sodium dodecyl sulfate and lithium dodecyl sulfate, in molten acetamide were carried out at 90 degrees C. Both methods show that micelles are formed in acetamide solution. The critical micelle concentration was determined for each of the surfactants. It is suggested that the simplest formula of the ionic micelle is (S-)(n)(CH3CONH2)(x), and at higher concentration the micelle may be of the form (NaS)(m)(S-)(n)(CH3CONH2)(x), where NaS = sodium stearate. (C) 1997 Elsevier Science B.V.