Molecular mechanism of calcium sulfonate redissolution by micelles

It has been suggested that redissolution of sulfonate/multivalent precipitates occurs by micellar solubilization. The molecular mechanism governing the redissolution process has not been identified. In this study, the solubilization constant, which is an indicator of the capacity of the micelles to solubilize the precipitate, is determined with the aim of elucidating the molecular mechanism involved in the redissolution process. The effects of ionic strength, alkyl chain length, temperature, n‐propanol and n‐dodecane on the solubilization constant are examined under a variety of conditions. In addition, counter‐ion binding to micelles and conductivity of micelles are determined for different sulfonates. Based on all these data, a mechanism involving the adsorption of Ca²⁺ on the micelle and the subsequent dissolution of calcium disulfonate to replenish the system is proposed to account for the precipitate redissolution.