Interaction Between Cationic and Anionic Surfactants: Detergency and Foaming Properties of Mixed Systems

摘要

The micellar and interfacial behavior of mixtures of the anionic surfactant (alcohol ether sulfate, AES) with quaternary ammonium type cationic surfactants dodecyltrimethyl ammonium chloride (DTAC), dodecyl-(2-hydroxyethyl)-dimethyl ammonium chloride (DHDAC), dodecyl-di(2-hydroxyethyl)-methyl ammonium chloride (DHHAC) were investigated by means of surface tension measurements. Various physicochemical properties such as surface activity parameters (CMC, γ_(CMC), Γ_(max), A_(min)), the micellar and interfacial compositions (x_1~m x_1~σ), interaction parameters (β~m, β~σ), and activity coefficients (f_1~m f_2~m, f_1~σ, f_2~σ) were evaluated. The influence of the hydroxyethyl groups of cationic surfactant component on the physico-chemical properties of mixed systems has been analyzed. It is observed that the CMC values of the three mixed systems decrease with increases in the number of hydroxyethyl groups of the cationic surfactant component. From the results of β~σ and β~m values, the interactions between molecules for the three surfactant mixtures at the air/liquid interface increase in the following order DHHAC/ AES < DHDAC/AES < DTAC/AES, but it is the opposite for the interactions in mixed micelles. The detergency and foaming properties of mixed systems were also studied. As expected, complex surfactant systems exhibit good detergency and foaming properties.