CHARACTERIZATION OF THE SOLUTION PROPERTIES OF A 1.7-PERCENT SULFONATED POLYSTYRENE IONOMER BY FLUORESCENCE PROBING

Luminescent probing methods were employed to investigate the solution characteristics of a 1.7% sulfonated Polystyrene ionomer in a nonpolar solvent. Ion pair/ion pair interactions were shown to give rise to ionic microdomains averaging 6-7 sulfonate groups per aggregate; in dilute solution ion aggregation is only 2-3. The ionic aggregates were shown to maintain constant dimensions over a wide concentration range, indicative of the integrity of the primary aggregates even at high concentrations where the ionomers begin to associate. Inhibition of fluorescence quenching demonstrates that ionic material supported in these systems are effectively screened from the bulk solution phase and is attributed to a mantle of hydrocarbon polymer chain about the ionic regimes. Reactivity of ionic species was manipulated by the addition of a small amount of polar solvent, which acts to disrupt the aggregation and expose the solvated ionic material to reactants in the bulk solution phase.