Environment-friendly ester bonded gemini surfactant: Mixed micellization of 14-E2-14 with ionic and nonionic conventional surfactants

This paper deals with a comprehensive study of the biodegradability, cleavability, hemolytic activity, and physicochemical properties of an ester-linked gemini surfactant, ethane-1,2-diyl bis(N,N-dimethyl-N-tetradecylammoniumacetoxy) dichloride (14-E2-14), along with the gemini-conventional mixed surfactant systems at different mole fractions of 14-E2-14. Some typical conventional surfactants of different polarities were used in the investigation at 303.15 K in aqueous medium by performing conductometric and tensiometric measurements. The data from both the techniques were used to obtain the critical micelle concentration (cmc) of mixed surfactant systems at different mole fractions. The decrease in cmc values indicates nonideality of the binary systems, and also occurrence of mixed micellization. Interaction parameters (βm and βσ) along with energetics of mixed micellization were evaluated by using theoretical models suggested by Clint, Rubingh, Rosen, Motomura and Maeda for mixed surfactant systems. Negative values of β indicate an overall attractive force in the mixed state. Also, the excess free energy of mixing has negative values for all the systems. The hydrophilic spacer of the gemini surfactant 14-E2-14 shows strong interaction with the conventional surfactants used as well as with the biological membranes such as human erythrocytes (RBC).