Interaction, Surface Activity, and Application of Mixed Systems of Alcohol Ether Sulfate Anionic Surfactants with Multiple Ethylene Oxide Groups and Gemini Quaternary Ammonium Surfactant

Abstract

The surface activities and application properties for the mixtures of cationic surfactants tetramethylene-1,4-bis[ N, N -bis(hydroxypropyl)-hexa/decyloxypropylammonium] bromide (GC 10 -P) and tetramethylene-1,4-bis[ N, N -bis(hydroxyethyl)-hexa/decyloxypropylammonium] bromide (GC 10 -E) and anionic surfactant isomeric sodium fatty alcohol ether sulfates (iso-AE 9 S) were investigated using both the tensiometry and the conductometry. The interaction parameters and thermodynamic micellization parameters of GC 10 -P/iso-AE 9 S and GC 10 -E/iso-AE 9 S mixtures were evaluated by Clint–Rubingh and Motomura theoretical models. When the mole fraction of α 1 for GC 10 -P/iso-AE 9 S mixed system was 0.2, the critical micelle concentration (CMC) reached a minimum of 1.61 × 10 –4 mol/L, and the minimum critical micelle concentration of the GC 10 -E/iso-AE 9 S mixed system is 2.67 × 10 –5 mol/L at α 1 = 0.6. The CMC value of the mixed system is 1–2 orders of magnitude lower than that of any single component. The results indicate that the synergistic effects of the investigated mixed systems (evaluated by β m ) are in order of GC 10 -P/iso-AE 9 S < GC 10 -E/iso-AE 9 S, with maximum β m values of −17.98 and −9.78, respectively. The change in zeta potential indicates that the poly(ethylene oxide) chain has weakened the charge density of the hydrophilic headgroup of the anionic surfactant. The interfacial tension at the oil–water interface in the mixed system of anionic/cationic surfactants is lower than that of any single component, exhibiting a higher interfacial activity. The mixed system exhibits a decreased contact angle and superior wetting ability over any single component, and it also enhances foam performance, emulsification performance, and degreasing performance.

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