Sugar-based cationic surfactants: Synthesis and aggregation of methyl 2-acylamido-6-trimethylammonio-2,6-dideoxy-D-glucopyranoside chlorides

The synthesis of the sugar-based cationic surfactants methyl 2-acylamido-6- trimethylammonio-2,6-dideoxy-D-glucopyranoside chlorides is reported here. Aggregation of these surfactants (predominantly a anomers) in water was stu died at 25 degreesC by conductivity measurements. Increasing the chain leng th of the amido group R decreased the critical micelle concentration (CMC) and the degree of counter-ion dissociation. The dependence of the Gibbs' fr ee energy of micellization and CMC on the length of R is similar to that ob served for other ionic surfactants. The free energy of transfer of the head group, i.e., cationic amino sugar moiety, from water to the micelle is mor e negative than that of other ionic surfactants, including sodium methyl 2- acylamido-2-deoxy-6-O-sulfo-D-glucopyranosides, probably due to a combinati on of a micellar "medium" effect and intermolecular H-bonding in the micell ar pseudophase.