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Synthesis and Surface Active Properties of a Gemini Imidazoline Amphoteric Surfactant
Author(s) -
Xu Yuanhong,
Xu Hujun
Publication year - 2016
Publication title -
journal of surfactants and detergents
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.349
H-Index - 48
eISSN - 1558-9293
pISSN - 1097-3958
DOI - 10.1007/s11743-016-1841-8
Subject(s) - chemistry , pulmonary surfactant , critical micelle concentration , lauric acid , triethylenetetramine , surface tension , ethylene oxide , isopropyl alcohol , alcohol , aqueous solution , nuclear chemistry , perchloric acid , titration , micelle , inorganic chemistry , organic chemistry , copolymer , biochemistry , fatty acid , physics , quantum mechanics , polymer
The gemini imidazoline amphoteric surfactant was prepared in two steps. We first reacted lauric acid and triethylenetetramine to obtain the intermediate called bisalkyl‐bis‐imidazoline. We analyzed it by 1 H NMR, and the yield was 82.45 % according to perchloric acid non‐aqueous titration. The intermediate was then quaternized using sodium 2‐chloroethanesulfonic acid in a mixture of isopropyl alcohol and water, during which we controlled the pH between 8 and 9 and the temperature between 80 and 90 °C to prepare C12‐bis‐imi. The air–liquid surface tension was measured by a tensiometer at 298 ± 0.1 K. The results show that the critical micelle concentration (CMC) was 2.25 × 10 −3 mol/L and the surface tension at the CMC ( γ CMC ) was 30.42 mN/m. C12‐bis‐imi showed a synergistic effect in combination with lauric alcohol with nine ethylene oxide groups (AEO9). The synergistic effect is most striking when the mole ratio of C12‐bis‐imi/AEO9 was 1/1, and the corresponding CMC was 9.79 × 10 −5 mol/L and the γ CMC was 37.61 mN/m.