SPECTROSCOPIC CHARACTERIZATION OF UNIMER MICELLES OF HYDROPHOBICALLY-MODIFIED POLYSULFONATES

Polysulfonates modified with bulky hydrophobic groups of cyclic structure form unimolecular micelles (unimers) in aqueous solution owing to intramolecular self-organization, This chapter deals with the characterization of the unimers of random copolymers of sodium 2-(acrylamido)-2-methylpropanesulfonate and hydrophobic methacrylamides carrying cyclododecyl, 1-adamantyl, or 1-naphthylmethyl substituent group, by light scattering, small-angle X-ray scattering, fluorescence, NEAR, and IR techniques. The absence of intermolecular association is indicated by the absence of non-radiative energy transfer from naphthalene to pyrene which are labeled respectively on the individual polymer molecules. Light scattering studies show that the unimers have extremely large ratios of mass to dimension indicating an extremely compact conformation. Local motions of the hydrophobes in the unimers are highly restricted as indicated by H-1-NMR relaxation times. FTIR indicates that hydrogen bonding between the spacer amide bonds contributes to the stabilization of the compact unimer structure.