Polyaniline Nanofiber-Metal Salt Composite Materials for Arsine Detection

We report the use of polyaniline nanofiber-metal salt composites for the detection of arsine gas (AsH3) using the resistance change of the materials. Aqueous dispersions of polyaniline nanofibers facilitate the preparation of metal salt/polyaniline nanofiber composites with the use of water-soluble inorganics. Various composites were tested Including CuCl2, CuBr2, CuF2, Cu(O2CCH3)(2), Cu-(NO3)(2), EuCl2, NiCl2, FeCl3, and CoCl2. The copper(II)bromide/polyaniline nanofiber composite yields the best response with greater than ail order of magnitude change in resistance upon exposure to arsine. The response is dependent on the metal and the counterion of the metal salt, as well as environmental conditions such as temperature and humidity. A mechanism that involves redox chemistry of the metal ion, polyaniline and AsH3 is proposed and discussed.