Sugar-based anionic surfactants:: synthesis and micelle formation of sodium methyl 2-acylamido-2-deoxy-6-O-sulfo-D-glucopyranosides

The following sequence of reactions has been employed to synthesize the title anionic surfactants: [GRAPHICS] where R=C7H15; C11H23; and C15H31, respectively, and Py refers to pyridine. Aggregation of the surfactants synthesized (predominantly alpha anomers) in water was studied at 40 degreesC by conductivity measurements. Increasing the chain length of R decreases the critical micelle concentration (CMC) and the degree of counter-ion dissociation. The dependence of the Gibbs free energy of micellization and CMC on the length of R is similar to other ionic surfactants, but the head-group, i.e., the sulfated sugar moiety is less hydrophilic than the structurally related group -(OCH2-CH2)(2)-OSO3-Na+, most probably because of intermolecular H-bonding in the micellar pseudo-phase (C) 2001 Elsevier Science Ltd. All rights reserved.