Supramolecular “Leeks” of a Fluorinated Hybrid Amphiphile that Self- Assemble into a Disordered Columnar Phase

We report on the formation of unprecedented ?Leek? shaped aggregates of an anionic fluoroalkyl sulfonate surfactant (FS), and the supramolecular assembly of these aggregates into a disordered columnar phase (CS). The leeks are formed by wrapping of 2 to 3 FS-water bilayers of thickness 26-28 Å into 10-20 nm thick and >100 nm long structures, in the concentration regime of 63 to 70 wt% of FS. A lamellar (Lα) lyotropic liquid crystalline (LLC) phase forms at higher concentration, between 70 to 84 wt%. In both LLC phases the FS molecules were organized in an interdigitated or tilted fashion, or combination of the two. Such a unique supramolecular self-assembly of amphiphiles has not been predicted nor observed before. This self-assembly behavior could be of interest to various fields like microencapsulation, nanomedicine, and membrane protein crystallization.