Solubilization Behavior of Organic Mixtures in Optimum Winsor Type III Microemulsion Systems of Sodium Dodecyl Sulfate. Issue 4 (28th May 2018) - Liu, Huie
Abstract: Solubilization selectivity and synergism behavior were investigated for the optimum Winsor type III sodium dodecyl sulfate (SDS) microemulsion systems of organic mixtures. The organic mixtures used include toluene and 1 of the following 3 normal alkanes: n ‐octane, n ‐heptane, and n ‐hexane. Selective solubilization toward toluene was observed in the optimum Winsor type III SDS microemulsion system for the toluene/ n ‐octane mixture. Toluene selectivity showed a decrease trend with the increase of its content in the excess oil phase, salinity showed little influence on the trend, and increasing of the SDS content leads to lowering of the selectivity. Synergism exists in the solubilization of the 2 organics for all the binary mixtures used in this work. A clear reduction of the n ‐butanol content ( A *) to obtain the optimum formulation and rise of the optimum solubilization parameter ( SP *) were seen with the mixing of 2 single components. Coincident relation between A * and equivalent alkane carbon number (EACN) for organic mixtures of toluene with the 1 or 3 of n ‐hexane, n ‐hexane, and n ‐octane was obtained, which is a parabolic curve with a minimum point. At the same time, all the SP *–EACN data fall in the same kind of parabolic curve with a maximum. The EACN for the minimum A * and maximum SP * are both in the range of 3.0–3.5. The A *–EACN curve shifts vertically with the change of the SDS content or ln S * ( S * is salinity of the aqueous phase), while the change of salinity also leads to slight deformation of the curve, which can be omitted in a small range of salinity change.