On the shape of giant micelles in aqueous solutions of cetyltrimetylammoniumbromide (CTAB)

Low-temperature electron microscopy was used to image fracture faces of shock-frozen aqueous solutions containing the very large micelles of CTAB existing in the presence of N-methyl-N,N-diphenylamine (MDPA) and 9-anthracene carboxylic acid (9-AC) as solubilizates. When MDPA is present, large globular micelles are formed which have total aggregation numbers of the order of 10⁵ and are seen to be clusters of smaller disc-like structures containing some thousand CTAB-units. Thread-like features are visualized in solutions containing 9-AC which is known to induce the formation of micellar rods.