文摘
The absorption and fluorescence properties of a polyphenylethynylene based conjugated polyelectrolyte withsulfonate solubilizing groups (PP2) are shown to change dramatically with solution conditions because ofthe equilibrium between unaggregated and aggregated forms of the polymer. The fluorescence of PP2 isstrongly quenched on addition of counterions such as Na+, K+, Li+, and TBA+, an effect which arises fromthe creation of salt stabilized aggregates. The formation of aggregates has been further corroborated byconcentration and temperature studies in water and comparisons to dimethylsulfoxide solvent, in which thepolymer does not aggregate. In aqueous solutions, the addition of the cationic surfactant, octadecyltrimethylammonium, causes the polymer aggregates to dissociate and creates polymer/surfactant aggregates that havespectral properties like that of the unaggregated polymer.