Kinetics of crystallization in conducting polymers observed from electron spin resonance

Abstract

Electron spin resonance (ESR) spectra of pressed pellets of ClO4- doped poly(3-methylthiophene) (P3MT) were recorded as a function of time for samples quenched to 110 K and rapidly heated to 223 K. For a thin sample, fitting the ESR spectra with two Lorentzian absorption lines we were able to follow the decrease of the narrow line associated with the amorphous fraction of the polymer and the increase of the broad line, corresponding to the crystalline fraction. The crystallization process is discussed in terms of Avrami's equation and confirmed from differential scanning calorimetry (DSC) data. © 1998 American Institute of Physics.