Magnetic susceptibility and electron spin resonance investigations of polyaniline and polyaniline–poly(methyl methacrylate) blend

Magnetic susceptibility and electron spin resonance (ESR) investigations of polyaniline and polyaniline–poly(methyl methacrylate) (40:60) blend, both doped with paratoluenesulfonic acid, are presented as a function of temperature on unannealed and annealed samples. It is shown that magnetic susceptibility measurements yield the same value for density of states at the Fermi level as the one obtained from heat capacity measurements. Furthermore, ESR and magnetic susceptibility measurements are shown to indicate different structural order in polyaniline and the polyaniline–poly(methyl methacrylate) blend.