Synthesis and Dynamics of Oligomeric Micelles

The synthesis and characterization of three oligomeric surfactants from sodium 10-undecenoate, sodium 11-dodecenoate, and sodium 12-tridecenoate are described. These oligomers were prepared from sodium carboxylates with a terminal double bond by using ammonium persulfate as an initiator in aqueous, micellar solutions. They were characterized by using carbon-13 NMR and infrared spectroscopy. Carbon-13 NMR relaxation times were also used to probe the internal motion in oligomeric surfactants, and these results were compared to those for the corresponding saturated and unsaturated monomeric surfactants. It is found that in the oligomeric surfactants there is a motional gradient opposite to that found in monomeric species (i.e., the hydrocarbon interior is slower than near the head group). © 1989 American Chemical Society