Annealing effect in polyaniline-CSA upon moderate heating

Heating of polyaniline-CSA films in ambient air usually results in accelerated ageing, as evidenced by a progressive disappearance of the crystallinity and of the metallic features. However, after moderate heating (typically for 30 min at 135 °C), an annealing effect is observed: X ray diffraction shows an increase of the crystallinity, while low temperature dc conductivity, NIR reflectance and magnetoresistance data reveal that the transport properties are improved, with a more metallic behaviour.