Advances in synchrotron scattering methods for probing the self-assembly pathways in dilute surfactant solutions

This article presents the recent progress of synchrotron scattering methods for elucidating the self-assembly pathways in dilute surfactant systems. An order of magnitude increases in the source brilliance, together with advanced detectors enable time-resolved structural investigations of relatively low contrast and dilute surfactant solutions in the millisecond range. This is demonstrated by monitoring the structural evolution in mixtures of cationic and anionic surfactants well below their individual critical micelle concentration, upon rapid mixing using a stopped-flow device. Despite the low concentration of surfactants in these samples, well-defined nanostructures were detected within in the mixing time of the stopped-flow device (ca. 2 ms). These transient structures have a more elongated morphology than spherical unilamellar vesicles and they grow over the subsequent seconds. The results demonstrate that the spontaneous self-assembly occurs even in dilute solutions without any pre-existing motifs, which may be relevant in applications where high surfactant concentrations are inappropriate.

Automated summary

This article presents the recent progress of synchrotron scattering methods for elucidating the self-assembly pathways in dilute surfactant systems. The improved source brilliance and advanced detectors enable time-resolved structural investigations of low contrast and dilute surfactant solutions in the millisecond range. The results demonstrate that spontaneous self-assembly occurs in dilute solutions without any pre-existing motifs.