Electron Microscopic Observation on the Elongated Micelle in Cationic Surfactant with Some Aromatic Additives

Abstract

The solution of cationic surfactants cetyltrimethylammonium bromide etc., added with aromatic substances such as salicylic acid or its sodium salt shows remarkable viscoelasticlty even in very dilluted state. In this report, various cationic surfactant-additive systems were examined through electron microscopy to disclose visually the relation of solution viscoelasticity to micellar shapes and sizes. Without exception, in these systems which develop the spectacular behavior in solution, the authors have confirmed the existence of extremely elongated rod-like micelles which seem to cause the high viscoeias ticity after framing a network structure. We have been able to give one of a brief and direct evidence to the theories of construction of viscoelastic gels in solution which have been stated for a long period.