Polyaniline Microrods

摘要

Polyaniline (PANI) prepared in water or a water-methanol (1:1) mixed solvent by anodic oxidation of aniline hydrochloride at a potential of 0.8 V (and higher) vs. Ag/AgCl appears to form microrods of almost uniform shape and dimensions: a diameter of 0.7 μm and a length of 2-3 μm or more. A surface point contact Pt or Ir electrode has been used as the working electrode to get a better ordering in the product due to the surface tension effect. The structure observed with a scanning electron microscope (SEM) is complex: the sample is highly porous and looks like a coral reef; the average channel diameter is 1.5 and 2.5 μm for narrow and wide channels respectively. The rods appearing in great number in the sample are surprisingly uniform, particularly with respect to the diameter. The electrical conductivity is of the order of 10~(-1) S cm~(-1) for most samples examined. The electron spin resonance (ESR) spectra consist of a strong singlet line (g = 2.0030-2.0039, ΔH = 0.12-0.50 mT); similarly, the infrared (IR) spectra show a strong and broad absorption due to electron excitations and electron-lattice interactions, which we have observed previously for many PANI samples examined in our laboratory.