Strong methanesulfonic acid (MSA) was used as solvent to prepare blends of polyaniline (PAn) and poly(4-vinyl pyridine) of different compositions. Products obtained after removal of MSA were surveyed by scanning and transmission electron microscopes (SEM and TEM) to reveal their morphologies. The blend with 80 wt% of PAn showed an interesting elliptical flake morphology, in contrast to the spherical particle morphology observed for other blends. (C) 2001 Elsevier Science Ltd. All rights reserved.