The Effect of Urea on the First and Second CMC’s of Aqueous Solutions of Sodium and Lithium Dodecyl Sulfates

The effect of urea on the 1st and 2nd CMC’s of aqueous solutions of sodium and lithium dodecyl sulfates was investigated by the measuments of electric conductivity. The results were discussed in terms of the breaking effect of urea on the water structure not only around the hydrocarbon chains, but also around the counter ions of these surfactants.