Facile preparation of optically active polyanilines via the in situ chemical oxidative polymerisation of aniline

Optically active polyaniline in the non-doped emeraldine oxidation state an d as the polymer doped with HCl have been synthesised via the facile in sit u deposition of films from an aqueous solution of aniline undergoing oxidat ive polymerisation. Films of optically active polyaniline doped with (+)- o r (-)-10-camphorsulfonic acid (PAn.HCSA) were first deposited from a soluti on of aniline by ammonium persulfate in the presence of (+)- or (-)-HCSA. T heir UV-visible and circular dichroism (CD) spectra suggest significant str uctural differences to PAn.HCSA salts prepared electrochemically. De-doping of the in situ deposited films with aqueous NH,OH gave optically active em eraldine base films, which could be re-doped with HCl vapour or 1.0 mol dm( -3) aqueous HCl to generate optically active PAn.HCl films with retention o f polymer configuration. (C) 1999 Elsevier Science S.A. All rights reserved .