Synthesis and Surface Active Properties of a Novel Linear Dodecyl Diphenyl Ether Sulfonate Gemini Surfactant

AbstractThe linear dodecyl diphenyl ether sulfonate gemini surfactant (C12‐DLADS) has been synthesized by a new route from lauric acid according to a five‐step reaction sequence consisting of acidification, Friedel–Crafts acylation, Clemmensen reduction, sulfonation and a neutralization reaction. The surfactant and intermediates were characterized by 1H‐NMR, HPLC/MS and elemental analysis. The properties have been studied by surface tension (γCMC) and conductivity measurements. The thermodynamic parameters of micellization were calculated. The test results show that C12‐DLADS has lower critical micelle concentration (CMC) and better capability for lowering the γCMC. The γCMC and CMC are 36.04 mN/m and 6.03 × 10−4 mol/L respectively at 45 °C. Moreover, with the increase in temperature, the conductivity of C12‐DLADS increased, while the counterion binding K0 decreased. The thermodynamic data show that the micellization process for the surfactant C12‐DLADS is entropy driven.