The Effect of Metallic Ions on Surface Chemical Phenomena. IV. Surface Tension Measurement on Aqueous Solutions of Metal Dodecyl Sulfates

Abstract

The surface tension of aqueous solutions of various metal dodecyl sulfates with divalent cations was measured at various temperatures with a Du Noüy’s tensiometer. The values of surface tension were observed to decrease steeply with the increase of their concentrations up to their cmc’s, which are all nearly equal to 1×10−3 mol./1. These values of cmc of the metal dodecyl sulfates with divalent cations were found to be practically independent of temperature and the kind of these cations. Further, the dye titration methods were also performed to obtain the values of cmc of these, metal dodecyl sulfates using pinacyanol chloride and rhodamine 6G. The values of cmc obtained by these methods were found to coincide with those from the surface tension measurements.