title: Worming their way into shape: toroidal formations in micellar solutions.
abstract: We report the formation of nanostructured toroidal micellar bundles (nTMB) from a semidilute wormlike micellar solution, evidenced by both cryogenic-electron microscopy and transmission electron microscopy images. Our strategy for creating nTMB involves a two-step protocol consisting of a simple prestraining process followed by flow through a microfluidic device containing an array of microposts, producing strain rates in the wormlike micelles on the order of 10(5) s(-1). In combination with microfluidic confinement, these unusually large strain rates allow for the formation of stable nTMB. Electron microscopy images reveal a variety of nTMB morphologies and provide the size distribution of the nTMB. Small-angle neutron scattering indicates the underlying microstructural transition from wormlike micelles to nTMB. We also show that other flow-induced approaches such as sonication can induce and control the emergence of onion-like and nTMB structures, which may provide a useful tool for nanotemplating.
authors.affiliation: Department of Mechanical Engineering and ‡Department of Biological Structure, University of Washington , Seattle, Washington 98195, United States.
authors.forename: Joshua J
authors.initials: JJ
authors.lastname: Cardiel
authors.forename: Lige
authors.initials: L
authors.lastname: Tonggu
authors.forename: Alice C
authors.initials: AC
authors.lastname: Dohnalkova
authors.forename: Pablo
authors.initials: P
authors.lastname: de la Iglesia
authors.forename: Danilo C
authors.initials: DC
authors.lastname: Pozzo
authors.forename: Liguo
authors.initials: L
authors.lastname: Wang
authors.forename: Amy Q
authors.initials: AQ
authors.lastname: Shen