Study of the conducting state of polyaniline close to the metal insulator transition

The conductive properties of two series of camphorsulphonic acid protonated polyaniline films spun from m-cresol and hexafluoropropanol solutions are probed by means of high frequency experiments as a function of temperature. Furthermore, the DC conductivity and room temperature optical absorption h ave been studied. In contrast to the DC conductivity, the microwave respons e depends weakly on temperature and reveals a gradual transition from metal lic to insulating behavior upon cooling.