Cylindrical micelles of wormlike polyelectrolytes

We report on a study of the association behavior in solution of semirigid p olymers consisting of a poly(p-phenylene) backbone with alternation of nega tively charged and hydrophobic moieties. Small-angle X-ray scattering data of aqueous solutions of sulfonated poly(p-phenylene)s show aggregated polym er chains in the form of cylindrical micelles, in which the phenylene backb one is oriented parallel to the long axis of the micelle. The charge densit y and the length of the alkyl side chains influence the diameter and aggreg ation number of the micelles. Micelles with strand aggregation numbers betw een 3 and 11 are formed depending on the hydrophobic-hydrophilic balance. T he observed behavior resembles the formation of supermolecular structures b y biogenic semirigid polyelectrolytes.