title: Encapsulation of poly(3-hexylthiophene) J-aggregate nanofibers with an amphiphilic block copolymer.
abstract: Poly(3-hexylthiophene) (P3HT) nanofibers (NF) displaying J-aggregate exciton coupling behavior are encapsulated with the amphiphilic block copolymer (BCP), poly(3-hexyl-thiophene)-block-poly(ethylene-glycol), (PHT(20)-b-PEG(108)). Encapsulation results in the formation of hierarchical superstructures, and the BCP coating is expected to exert a mild chemical pressure on the periphery of the NFs. Photoluminescence from encapsulated NF superstructures show line shape distortions due to self-absorption of the 0-0 transition which is consistent with preservation of J-aggregate character (intrachain order). Detailed resonance Raman spectra of encapsulated BCP-NF structures show no discernible changes in the P3HT aggregation state, and overtone and combination bands involving the symmetric stretching C═C (~1450 cm(-1)) and C-C (~1380 cm(-1)) backbone modes are observed. These features permit quantitative estimates of vibrational mode-specific excited state structural displacements using a time-dependent Raman intensity analysis which is not possible from conventional vibronic analysis of optical lineshapes.
authors.affiliation: Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, New Mexico 87131, USA.
authors.forename: Jian
authors.initials: J
authors.lastname: Gao
authors.forename: Amanda
authors.initials: A
authors.lastname: Kamps
authors.forename: So-Jung
authors.initials: SJ
authors.lastname: Park
authors.forename: John K
authors.initials: JK
authors.lastname: Grey