Tuning percolation speed in layer-by-layer assembled polyaniline–nanocellulose composite films

Sara Shariki, Soon Yee Liew, Wim Thielemans, Darren A Walsh, Charles Y Cummings, Liza Rassaei, Matthew J Wasbrough, Karen J Edler, Michael J Bonne, Frank Marken

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18 Citations (Scopus)

Abstract

Polyaniline of low molecular weight (ca. 10 kDa) is combined with cellulose nanofibrils (sisal, 4-5 nm average cross-sectional edge length, with surface sulphate ester groups) in an electrostatic layer-by-layer deposition process to form thin nano-composite films on tin-doped indium oxide (ITO) substrates. AFM analysis suggests a growth in thickness of ca. 4 nm per layer. Stable and strongly adhering films are formed with thickness-dependent coloration. Electrochemical measurements in aqueous H(2)SO(4) confirm the presence of two prominent redox waves consistent with polaron and bipolaron formation processes in the polyaniline-nanocellulose composite. Measurements with a polyaniline-nanocellulose film applied across an ITO junction (a 700 nm gap produced by ion beam milling) suggest a jump in electrical conductivity at ca. 0.2 V vs. SCE and a propagation rate (or percolation speed) two orders of magnitude slower compared to that observed in pure polyaniline This effect allows tuning of the propagation rate based on the nanostructure architecture. Film thickness-dependent electrocatalysis is observed for the oxidation of hydroquinone.
Original languageEnglish
Pages (from-to)2675-2681
Number of pages7
JournalJournal of Solid State Electrochemistry
Volume15
Issue number11-12
DOIs
Publication statusPublished - Dec 2011

Keywords

  • junction
  • cellulose
  • phase propagation rate
  • voltammetry
  • layer-by-layer assembly
  • nanocrystal
  • percolation
  • PANI
  • polyaniline
  • electrochromism Electrocatalysis
  • nanofibril

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    Shariki, S., Liew, S. Y., Thielemans, W., Walsh, D. A., Cummings, C. Y., Rassaei, L., Wasbrough, M. J., Edler, K. J., Bonne, M. J., & Marken, F. (2011). Tuning percolation speed in layer-by-layer assembled polyaniline–nanocellulose composite films. Journal of Solid State Electrochemistry, 15(11-12), 2675-2681. https://doi.org/10.1007/s10008-010-1261-z