ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Reduction of silver nitrate by polyaniline nanotubes to produce silver-polyaniline composites

Jaroslav Stejskal, Miroslava Trchová, Libuše Brožová, and Jan Prokeš

Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, 162 06 Prague 6, Czech Republic

E-mail: stejskal@imc.cas.cz

Received: 20 May 2008  Revised: 14 July 2008  Accepted: 23 July 2008

Abstract: Polyaniline (PANI) nanotubes were prepared by oxidation of aniline in 0.4 M acetic acid. They were subsequently used as a reductant of silver nitrate in 1 M nitric acid, water or 1 M ammonium hydroxide at various molar ratios of silver nitrate to PANI. The resulting PANI-silver composites contained silver nanoparticles of 40–60 nm size along with macroscopic silver flakes. Under these experimental conditions, silver was always produced outside the PANI nanotubes. Changes in the molecular structure of PANI were analyzed by FTIR spectroscopy. Silver content in the composites was determined as a residue by thermogravimetric analysis, and confirmed by density measurements. The highest conductivity of a composite, 68.5 S cm⁻¹, was obtained at the nitrate to PANI molar ratio of 0.67 in water. Also, the best reaction yield was obtained in water. Reductions performed in an acidic medium gave products with conductivity of 10⁻⁴–10⁻² S cm⁻¹, whereas the reaction in alkaline solution yielded non-conducting products.

Keywords: conducting polymer - conductivity - polyaniline - silver - nanotube

Full paper is available at www.springerlink.com.

DOI: 10.2478/s11696-008-0086-z

Chemical Papers 63 (1) 77–83 (2009)