EMF measurements in water at 25°C have been made using surfactant ion and counterion electrodes on two homologous series of long chain surfactants, the sodium alkylsulfates (R=n-C8H17 to n-C14H29) and the alkyltrimethylammonium bromides (R=C10H21 to C16H33). The data show evidence of association below the critical micelle concentration (CMC) but not of micelle ordering due to coulombic repulsion above this concentration.
- Surfactant ion-selective electrode
- alkyltrimethylammonium bromides
- critical micelle concentration
- sodium alkylsulfates