Solubilization of Ni Imidazole Complex in Micellar Media of Anionic Surfactants, Sodium Dodecyl Sulfate and Sodium Stearate

Abstract

AbstractThe solubilization and physicochemical behavior of a coordination complex of nickel, namely [Ni(im)6]F2·5H2O [hexakis(imidazole)nickel(II) fluoride pentahydrate], in aqueous micellar media of anionic surfactants, i.e., sodium dodecyl sulfate (SDS) and sodium stearate (SS), were investigated by using UV–Vis spectroscopy and electrical conductivity measurements. Spectroscopic techniques were used for the computation of binding constant (Kb), partition coefficient (Kx), change in free energy of binding (ΔGb), and change in free energy of partition (ΔGp), whereas electrical conductivity data was helpful to calculate thermodynamic parameters of micellization of surfactants in the presence of the Ni complex, i.e., standard entropy of micellization (ΔSm), free energy (ΔGm), and enthalpy of micellization (ΔHm). It is evident from the results that solubilization of the Ni complex takes place because of electrostatic as well as hydrophobic interactions. The presence of the Ni complex in micellar media increases the critical micelle concentration of both surfactants owing to the structure‐breaking effect.