From unsymmetrical bolaamphiphiles to supermolecules

Abstract

This paper describes the synthesis and self-assembly properties of bolaamphiphiles with two different head groups: a urocanic moiety and another group such as an active function (hydroxyl, carboxylic acid or methyl ester) or a sugar (arbutin). The morphologies of the aggregates formed by these amphiphiles in aqueous solutions were studied by light scattering and transmission electron microscopy and found to be strongly dependent on three parameters (pH, structure of the amphiphile and position of the connecting links on the imidazole moiety). These investigations reveal that the form of the aggregates is mainly affected by the presence and the number of hydrogen-bonding functions in the amphiphilic structure (from vesicles to flexible fibers then rigid fibers).