The Interaction of Sodium Dodecyl Sulfate with 4,5-Dihydroxy-1,3-Benzenedisulfonate Hydrotrope: Micellization, Surface Properties, and Thermodynamics

The study outlines the interaction between an extensively used surface-active agent, sodium dodecyl sulfate (SDS), and a hydrotrope, 4,5-dihydroxy-1,3-benzenedisulfonate (DHB), and the effect of temperature and concentration in the mixed-systems. The effect of DHB on the micellization of SDS at different temperatures was investigated by the conductometric method and surface tension measurements. The thermodynamic properties of SDS-DHB mixed systems were evaluated. The densities (ρ), dynamic viscosities (η), and kinematic viscosities (ν) of SDS in the presence and absence of DHB at various temperatures (293.15–333.15 K) with 5 K intervals have been investigated. The critical micelle concentration (CMC) value of SDS rise with an increase in temperature and drops with increasing concentration of DHB. With increasing temperature, the density, dynamic viscosity and kinematic viscosity of the pure SDS and mixed surfactant–hydrotrope (SDS-DHB) systems drop gradually. The synergistic effects are observed for the mixed surfactant-hydrotrope systems. The FTIR and Nuclear magnetic resonance (NMR) spectroscopic studies are used for characterization.