Determination of Critical Micel Concentration of PEG-10 Tallow Propane Amine: Effects of Salt and pH

Abstract

Most applications of surfactants depend on formation and characteristics of micelle. In this study we measured critical micelle concentration (CMC) of cationic surfactant N, N', N'-polyethylene (10)-N tallow-1, 3-di amine propane (PEG-10 tallow) in aqua solution by using electrical conductivity and surface tension methods. The CMC value of PEG-10 tallow with two different methods was found very close to 1.40 × 10 −3 M with electrical conductivity, and 1.41 × 10 −3 M with surface tension. It also investigated the effect of inorganic salt (NaCl) and pH on micellization of cationic surfactant PEG-10 tallow. With increasing addition of NaCl, formation of micelle structure resulted in a higher CMC. However, at low salt concentrations smaller CMC value was observed com-paring the critical micelle concentration of individual PEG-10 tallow. When it comes to the effect of changing pH in CMC of the PEG-10 tallow , it was clearly found that micelle formation or CMC of surfactant was indepen-dent on alkaline pH (between 6 and 10), but it was dependent on acidic pH (below 5).