Preparation and characterization of Ag/re-doped polyaniline nanoparticle composites

Abstract

Polyaniline is one of the most intensively investigated conjugated polymers because of attractive properties that include convenient synthesis, low cost, and unique doping mechanisms. While it has these intriguing properties, it unforutnately also exhibits effects related to its thermal stability. For example, the electrical conductivity of polyaniline at high temperatures (over 100oC) gradually decreases as a function of time due to thermal decomposition of the polyaniline structures[1,2]. In this study, we have synthesized Ag/re-doped polyaniline nanoparticle composites to enhance the thermal stability of the polyaniline. Polyaniline nanoparticles are prepared by micellar polymerization. Re-doped polyaniline nanoparticles are synthesized via doping, de-doping and re-doping processes. In the case of the re-doping process, mercaptosuccinic acid is used as a dopant in order to introduce silver to the polyaniline structure via sulfur-silver bonding. The Ag/re-doped polyaniline nanoparticle composite has been characterized using FT-IR, UV-vis spectroscopy, thermogravimetric analysis (TGA), and X-ray photoelectron spectroscopy (XPS). The thermal stability of the Ag/re-doped polyaniline nanoparticle is studied by measuring the surface resistivity of the nanoparticle film as a function of time at 100 and 120oC.