The chiral bilayer effect stabilizes micellar fibers

Abstract

Dihelical fibers several micrometers in length and gels were obtained by spontaneous aggregation of octyl L- and D-gluconamides. The single strands have the thickness of a bimolecular layer. No fibers are formed from the racemate. The tendency of the chiral amphiphiles to aggregate to very long fibers instead of three-dimensional crystals is rationalized with a “chiral bilayer effect”. This effect is caused by the slowness of rearrangements from tail-to-tail hydrophobic bilayers to crystals, in which the molecular sheets are arranged in a head-to-tail fashion. Thermograms which indicate slow rearrangements in ageing gels are also reported.