A Study on Polyaniline FTIR and Its Resistance under High Pressure

A Mao-Bell type of diamond anvil cell with Ⅱ-Type Diamond as anvil and infrared window has been used to study in situ Fourier transform infrared (FTIR) spectra of polyaniline under high pressures from 0 to 8.4 GPa. It shows that, between 4.8 and 5.2 GPa, areas of infrared absorption peaks standing for quinoid vibrations decrease compared to those caused by benzenoid vibrations, and this indicates that the structure of polyaniline has changed, and this kind of structural change is inconvertible. Resistance measurements of polyaniline under high pressures between 0 and 14.5 GPa show that resistance reduces dramatically with pressure increasing up to 7.5 GPa, at which a minimum of resistance-pressure curve occurs. These results suggest that polyaniline is a kind of electron conductive material, and its structural change leads to a minimum of resistance.