I would expect sharper peaks in the IR spectrum for materials with a higher crystallinity. Moreover, when comparing polyaniline materials crystallized under the same conditions, a higher crystallinity is most likely resulting from a more regular build-up of the polyaniline chains, which would also lead to sharper peaks in the IR region (more local variation in the chemistry implies the same functional group could be found in slightly different chemical environments, leading to slightly different vibration frequencies).

Kind regards,

Guy