Aggregation of new bipolar glucosyled and cationic fluoroamphiphiles in aqueous media

A new series of N-[3-(trimethylamino)propyl]-perfluoro-N-glucosyl amide-Iodides, differing by the length of the fluorocarbon tail (7, 9, and 11), have been synthesized in three steps involving unprotected glucose, N,N-dimethyl-1,3-propane diamine, the appropriate methyl-perfluoroalcanoate, and methyl iodide. Their aggregation and surface properties were studied in aqueous solution using conductivity, surface tension, and dynamic light scattering measurements. The critical micelle concentrations (CMC), the micellar aggregation numbers, the geometric packing parameters, the area/surfactant molecule at the interface, the surface excess concentration, the micellar ionization degree β, and the free energies of micellization have been investigated. DLS results show various morphologies of aggregates such as micelles and vesicles according to the increase in the hydrophobic chain length.

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► Perfluoro-lipids with an ammonium and a reducing sugar as heads are synthesized.
► The micellar behavior is examined as a function of the lipid structure.
► Thermodynamics show the contribution of the fluorinated tail to the micellization.
► Molecular surface areas and hydrodynamic diameters of the aggregates are determined.
► Despite their large polar heads such lipids can form both spherical and vesicular aggregates.