One-pot synthesis of a polyaniline–silver nanocomposite prepared in ionic liquid

Abstract

A mixture of aniline and a silver salt in ionic liquid has afforded a composite of PANI, in its more conducting form, and silver nanoparticles through a single-step direct reaction, without addition of any acid species or template. An ionic liquid acted as the solvent and template for the nanostructured material. The silver salt (AgTf₂N) used in this work is soluble in the chosen ionic liquid, which is not an usual characteristic. TEM analysis of the obtained composite showed the presence of rounded silver nanoparticles with average diameter size around 10–20 nm uniformly dispersed in the polymeric matrix. XRD corroborates the size of the metallic particles at the nanoscale. FTIR and UV-vis confirmed that PANI was obtained in emeraldine salt form. The composite is slightly soluble in DMSO, an unusual feature for bulk conducting polyaniline. The composite shows electrical conductivity 100 times higher than bulk PANI prepared by usual procedures and its electroactivity was studied by cyclic voltammetry. Therefore, in this study it was shown that Ag⁺, in ionic liquid, is able to quickly oxidize the aniline to PANI, which is not observed in another media.