Self-assembly of quaternary ammonium gemini surfactants in cyclohexane upon reinforcement by simple counterions.

The quaternary ammonium gemini surfactants 12--12 ( = 2, 6, and 10) can produce homogeneous cyclohexane solutions with the assistance of salts, sodium benzoate (NaBez), sodium salicylate (NaSal), or sodium 2-bromoethanesulphonate (NaBres). In these samples, 12--12/salt formed aggregates and their structures were assigned by SAXS measurements together with POM observations. Among the three salts, both NaBez and NaBres had similar effects on assisting aggregate formation, but NaSal favoured the generation of aggregates of 12--12 with lower interface curvature.