Mixed Micellization Properties of Nonionic Fluorocarbon/Cationic Hydrocarbon Surfactants

The physico-chemical properties of mixed surfactant aqueous solutions at various proportions of dodecyltrimethyl ammonium bromide DTAB and undecafluoro n-pentyl decaoxyethylene ether C5F11EO10 have been investigated at 25 A degrees C using surface tension and conductivity measurements. The critical micelle concentration and superficial minimum tension have been experimentally estimated for different DTAB molar fractions. The micellar composition and mutual interaction parameters have been deduced on the basis the theoretical treatments proposed by Clint, Rubingh, and Motomura. The results show a significant synergism effect at about equimolarity of DTAB/C5F11EO10 system probably due to the efficient electrostatic self-repulsion reduction between DTAB cationic head groups related to the presence of the nonionic surfactant in the mixed micelles.