Direct-Imaging Cryo-SEM of Nanostrutcture Evolution in Didodecyldimethylammonium Bromide-Based Microemulsions

We applied cryogenic-temperature scanning electron microscopy (cryo-SEM) to perform a first direct-imaging study of single-phase microemulsions of didodecyldimethylammonium bromide (DDAB), isooctane, and water. The structural changes from a bicontinuous network to an oil-continuous structure, observed upon the addition of water to the system, are consistent with previous indirect investigations, thus validating the model of Ninham, Evans, and coworkers, published in 1984, and demonstrating the power of this novel methodology.