Dispersion-induced insulator-to-metal transition in polyaniline

Melt dispersion processing - without solvents or "secondary dopants" - pushes polyaniline reproducibly to the metallic side of the IM transition, although the undispersed polyaniline is on the insulator side. This is the first time that a conductive polymer is found there without applying pressure. The transition to the metallic state is associated with a decrease of the C6-N-C6 angle from 166° to 134°.