Conductive, Monodisperse Polyaniline Nanofibers of Controlled Length Using Well‐Defined Cylindrical Block Copolymer Micelles as Templates. Issue 39 (9th August 2013)

• Record Type: Journal Article
• Authors: McGrath, Nina; Patil, Avinash J.; Watson, Scott M. D.; Horrocks, Benjamin R.; Faul, Charl F. J.; Houlton, Andrew; Winnik, Mitchell A.; Mann, Stephen; Manners, Ian
• Is Part Of: Chemistry. Volume 19:Issue 39(2013)
• Page Start: 13030
• Page End: 13039
• Publication Date: 2013-08-09
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201300589
• Languages: English
• ISSNs: 0947-6539

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>Stable colloidal dispersions of polyaniline (PAni) nanofibers with controlled lengths from about 200 nm–1.1 μm and narrow length distributions (<italic>L</italic><sub>w</sub>/<italic>L</italic><sub>n</sub><1.04; <italic>L</italic><sub>w</sub>=weight average micelle length, <italic>L</italic><sub>n</sub>=number average micelle length) were prepared through the template‐directed synthesis of PAni using monodisperse, solution‐self‐assembled, cylindrical, block copolymer micelles as nanoscale templates. These micelles were prepared through a crystallization‐driven living self‐assembly method from a poly(ferrocenyldimethylsilane)‐<italic>b</italic>‐poly(2‐vinylpyridine) block copolymer (PFS<sub>25</sub>‐<italic>b</italic>‐P2VP<sub>425</sub>). This material was initially self‐assembled in <italic>i</italic>PrOH to form cylindrical micelles with a crystalline PFS core and a P2VP corona and lengths of up to several micrometers. Sonication of this sample then yielded short cylinders with average lengths of 90 nm and a broad length distribution (<italic>L</italic><sub>w</sub>/<italic>L</italic><sub>n</sub>=1.32). Cylindrical micelles of PFS<sub>25</sub>‐<italic>b</italic>‐P2VP<sub>425</sub> with controlled lengths and narrow length distributions (<italic>L</italic><sub>w</sub>/<italic>L</italic><sub>n</sub><1.04) were subsequently prepared using thermal treatment at specific temperatures between 83.5 and 92.0 °C using a 1D self‐seeding process. These samples were then employed in the template‐directed synthesis of PAni nanofibers through a two‐step procedure, where the micellar template was initially stabilised by deposition of an oligoaniline coating followed by addition of a polymeric acid dopant, resulting in PAni nanofibers in the emeraldine salt (ES) state. The ES–PAni nanofibers were shown to be conductive by scanning conductance microscopy, whereas the precursor PFS<sub>25</sub>‐<italic>b</italic>‐P2VP<sub>425</sub> micelle templates were found to be dielectric in character.</p> </abstract>