AbstractWe investigated the effect of counter ion (Cu2+) adsorption on Sodium Dodecylsulfate and Sodium Tetradecylsulfate micelle by three different techniques: surface tension decrease, copper‐selective electrode and electric conductivity. The effect of added copper ion on critical micelle concentration (CMC) was determined. The effectiveness of these three techniques was critically evaluated. It is concluded that copper ions are able to strongly displace Sodium ions from the micellar surfac