The Kinetics of Oxidation of D-Sorbitol by Acidic KMnO4: Impact of Ag(I) and SLS Micellar Environment

Abstract

The current research examines the influence of sodium lauryl sulfate (SLS) micelles on the oxidation rate of D-Sorbitol by acidic Mn(VII), facilitated by Ag(I) in an aqueous medium. The progress of the reaction is studied by measuring the reduction in absorbance, employing the pseudo-first-order condition as an indicator of [SLS], [Ag(I)], [D-Sorbitol], ionic strength, [Mn(VII)], and [H⁺]. The reaction exhibits fractional-first-order dependence on [H⁺], [D-Sorbitol], and [Ag(I)], and first-order reliance on [Mn(VII)] across the examined concentration spectrum. The kinetic examination showed that while Ag(I) and SLS individually accelerate the process, their combination is significantly more effective. Ag(I) markedly enhances the oxidation rate by a factor of 5.2. The kinetic profile demonstrated a 6.8-fold enhancement in the rate constant with an increase in surfactant concentration. The synergistic effect of Ag(I) and SLS micelles leads to an 11.3-fold increase in the oxidation rate of D-Sorbitol. The oxidation process is expedited by the electrostatic interaction between Mn(VII) and the negatively charged SLS micelle, facilitating the proximity of the oxidant to the substrate (D-Sorbitol), which is typically soluble in a micellar environment. A credible mechanistic framework that aligns with the kinetic results is being emphasized to elucidate the observable catalytic influence of the SLS micellar environment.