Template synthesis of highly oriented polyfluorene nanotube arrays

Shane Moynihan, Daniela Iacopino, Deirdre O'Carroll, Pierre Lovera, Gareth Redmond

Research output: Contribution to journalArticle

40 Citations (Scopus)

Abstract

Polyfluorene nanotubes are synthesized by solution assisted wetting of porous anodic alumina membranes. Well aligned arrays of close packed (∼109 tubes/cm-2) discrete nanotubes are obtained. Individual tubes have diameters of ∼260 nm and wall thicknesses of ∼50 nm. X-ray diffraction measurements carried out on nanotube arrays embedded in host templates indicate a polymer chain alignment along the long axes of the template pores and, as a result, along the long axes of the nanotubes themselves. Optical spectroscopic studies of mats of nanotubes on glass substrates yield well resolved emission spectra reflecting a narrowed distribution of emitting chain segments with increased effective conjugation lengths. The data indicate intrachain reorientation of the amorphous random poly(9,9-dioctylfluorene-2,7-diy1) molecular conformation to the more planar (low energy) extended 21 helical β-phase conformation within the tubes. Raman spectra acquired for template embedded tubes are also consistent with β-phase formation. Finally, polarization resolved photoluminescence data demonstrate a pronounced axial orientation of the emissive β-phase chains within the tubes.

Original languageEnglish
Pages (from-to)996-1003
Number of pages8
JournalChemistry of Materials
Volume20
Issue number3
DOIs
Publication statusPublished - Feb 12 2008

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ASJC Scopus subject areas

  • Chemistry(all)
  • Chemical Engineering(all)
  • Materials Chemistry

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