One-pot synthesis of polyaniline - Metal nanocomposites

Composite materials consisting of polyaniline nanofibers decorated with noble-metal (Ag or Au) nanoparticles were synthesized with gamma radiolysis. Aqueous solutions of aniline, a free-radical oxidant, and/or a metal salt were irradiated with gamma rays. Exposure of the solutions to gamma rays caused aniline to polymerize as very-thin fibers. Metal particles were also formed during irradiation and decorated the fibers. The shape and size of the metal particles could be changed from nanometer-sized spheres to micron-sized dendrites by varying the ratio of aniline to the metal precursor. Polyaniline-metal composites were characterized using UV-Vis spectroscopy, infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and transmission electron microscopy (TEM). The electrical conductivity of the composites increased with the loading of metal in the nanocomposites and was up to 50 times greater than that of polyaniline fibers alone.