title: Solvation and aggregation of polyphenylethynylene based anionic polyelectrolytes in dilute solutions.
abstract: The absorption and fluorescence properties of a polyphenylethynylene based conjugated polyelectrolyte with sulfonate solubilizing groups (PP2) are shown to change dramatically with solution conditions because of the equilibrium between unaggregated and aggregated forms of the polymer. The fluorescence of PP2 is strongly quenched on addition of counterions such as Na+, K+, Li+, and TBA+, an effect which arises from the creation of salt stabilized aggregates. The formation of aggregates has been further corroborated by concentration and temperature studies in water and comparisons to dimethylsulfoxide solvent, in which the polymer does not aggregate. In aqueous solutions, the addition of the cationic surfactant, octadecyltrimethyl ammonium, causes the polymer aggregates to dissociate and creates polymer/surfactant aggregates that have spectral properties like that of the unaggregated polymer.
authors.affiliation: Chemistry Department, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA.
authors.forename: Palwinder
authors.initials: P
authors.lastname: Kaur
authors.forename: Hongjun
authors.initials: H
authors.lastname: Yue
authors.forename: Mingyan
authors.initials: M
authors.lastname: Wu
authors.forename: Min
authors.initials: M
authors.lastname: Liu
authors.forename: Jennifer
authors.initials: J
authors.lastname: Treece
authors.forename: David H
authors.initials: DH
authors.lastname: Waldeck
authors.forename: Cuihua
authors.initials: C
authors.lastname: Xue
authors.forename: Haiying
authors.initials: H
authors.lastname: Liu
mesh_terms: D000480:Alkynes / Q000737:chemistry*; D000838:Anions / Q000737:chemistry; D004573:Electrolytes / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D012995:Solubility; D012996:Solutions / Q000737:chemistry; D012997:Solvents / Q000737:chemistry; D013501:Surface-Active Agents / Q000737:chemistry
chemical_list: D000480:Alkynes; D000838:Anions; D004573:Electrolytes; D011108:Polymers; D012996:Solutions; D012997:Solvents; D013501:Surface-Active Agents; C522994:poly(2,5-bis(3-sulfonatopropoxy)-1,4-phenylethynylene-alt-1,4-polyphenylene ethynylene)