Surface and Interfacial Properties of Mono and Didodecyl Diphenyl Ether Disulfonates

Abstract

Abstract In this paper, monododecyl diphenyl ether disulfonate (C12-MADS) and didodecyl diphenyl ether disulfonate (C12-DADS) are Friedel-Craft reaction product of 1-dodecene and diphenyl oxide using sulfated zirconium as a catalyst, followed by sulfonation with fuming sulfuric acid in 1,2-dichloroethane and neutralization with aqueous sodium hydroxide solution. The relationship between the structures of the surfactants C12-DADS, C12-MADS and linear alkylbenzene sulfonate (C12-LAS) and their surface and interfacial properties was studied by measuring equilibrium surface tensions, dynamic surface tensions and dynamic interfacial tensions (IFT). The results show that the surface and interfacial activity of C12-MADS is better than that of C12-DADS and C12-LAS. The gemini surfactant C12-DADS shows most unfavorable surface and interfacial activity due to the fact that the cross-linked hydrophobic carbon chains decreases the number of exposed methyl in molecule. The dynamic surface tensions results show that the diffusion coefficients values of C12-MADS and C12-DADS are lower than that of C12-LAS, and the adsorption process of surfactants at air/water interface is a mixed diffusion-kinetic adsorption mechanism. The data of dynamic ITF between aqueous surfactants solutions and dodecane indicate that the NaCl and CaCl2 concentration has a weak effect on the stable value of dynamic IFT for C12-DADS. With increasing the NaCl and CaCl2 concentration, the stable values of dynamic ITF for the three surfactants mostly passes through a minimum at an optimum concentration, and the C12-MADS and C12-LAS can reduce the IFT to the 10−2 mN/m order of magnitude.