title: Chemical and photoluminescence properties of purified poly(2-methoxyaniline-5-sulfonic acid) and oligomer.
abstract: Both the chemical and the electrochemical synthesis of poly(2-methoxyaniline-5-sulfonate) (PMAS) in aqueous media have been found to give two distinct polymer fractions with molecular weights of approximately 8-10 and 2 kDa, respectively. It is now possible to isolate the pure high molecular weight (HMWT) PMAS and low molecular weight (LMWT) PMAS oligomer and to study their individual and combined photochemistry and redox chemistry. The HMWT PMAS fraction was confirmed to be an emeraldine salt by its characteristic redox and pH switching behavior, in contrast to the oligomeric LMWT PMAS, which was inert under the same conditions. Mixtures of these two fractions exhibit photoluminescence arising from the oligomeric LMWT PMAS fraction. The observed LMWT PMAS emission was modulated by the presence of the conducting HMWT PMAS emeraldine salt via a static resonant energy transfer arising from quenching at 460 nm when excited at 355 nm. The nonlinear fluorophore-quencher behavior suggests that the two PMAS fractions are strongly associated. The behavior fitted the static Perrin quenching model in which the oligomeric LMWT PMAS fluorophore is diffusionally restricted by the presence of HMWT PMAS quencher.
authors.affiliation: Intelligent Polymer Research Institute, ARC Centre of Excellence for Electromaterials Science, University of Wollongong, Northfields Avenue, Wollongong, NSW 2522, Australia. innis@uow.edu.au
authors.forename: P C
authors.initials: PC
authors.lastname: Innis
authors.forename: F
authors.initials: F
authors.lastname: Masdarolomoor
authors.forename: L A P
authors.initials: LA
authors.lastname: Kane-Maguire
authors.forename: R J
authors.initials: RJ
authors.lastname: Forster
authors.forename: T E
authors.initials: TE
authors.lastname: Keyes
authors.forename: G G
authors.initials: GG
authors.lastname: Wallace
mesh_terms: D000814:Aniline Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D049449:Luminescence; D015394:Molecular Structure; D008970:Molecular Weight; D010084:Oxidation-Reduction; D010777:Photochemistry; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry*; D012680:Sensitivity and Specificity; D013055:Spectrophotometry, Infrared / Q000379:methods; D013451:Sulfonic Acids / Q000138:chemical synthesis / Q000737:chemistry*
chemical_list: D000814:Aniline Compounds; D011108:Polymers; D013451:Sulfonic Acids; C525236:poly(2-methoxyaniline-5-sulfonic acid)