Interactions Between Cationic Gemini Surfactants and Nonionic Surfactant in Aqueous Solutions

Abstract

In this study, we have investigated mixed micelle formation in mixtures of cationic gemini and nonionic surfactant by conductivity at a certain micellar concentration range and certain temperature. The gemini surfactant of type alkanediyl-α-ω-bis (alkyldimethyl ammonium) dibromide with different alkyl groups referred as ''m-2-m" [CmH2m+1 (CH2)2 N + (CH2)2 N + (CH2)2 CmH2m+1, 2Br − ] (m = 12 and 16) have been synthesized, purified and characterized in our laboratory. Brij-35 (polyoxyethylene 23 lauryl ether) was used as the nonionic surfactant in experiments. Using the conductance measurements , we have been obtained the values of critical micelle concentrations (CMC) of the binary gemini-nonionic surfactant mixtures having different compositions. The composition of mixed micelles and the micellar interaction parameters, (β), were evaluated from the critical micelle concentration values for different mixtures using the approach of Rubingh`s regular solution theory. Mixed systems were exhibited negative synergism due to positive β values. The β values were found between about zero and 3.5. This indicates that the mixed micelle formation is ideal for Brij 35-(16-2-16) mixtures (β=0.087). Antagonistic interactions were observed in the case of Brij35-(16-2-16) dimeric cationic surfactant.