Nanoparticles of polyaniline have attracted increasing attention for their smaller size and large surface area which may promote more effective doping

overcome the problem of process ability and lead to special electrical

optical

opto-electrical properties．In this work

polyaniline nanoparticles doped with β-naphthalenesulfonic acid were prepared by a novel solid-state reaction synthesis method. Polyaniline was characterized by FT-IR

XRD and cyclic voltammogram on powder cavity microelectrode．The morphology of polyaniline particles was studied through SEM and TEM

and the electrical conductivity of pellets formed with polyaniline nanoparticles was measured by using a four-probe apparatus．Results showed that the average size of polyaniline particles doped with β-naphthalenesulfonic acid obtained by this method was 30～50 nm

and the polyaniline particles were spherical in shape．The measured electrical conductivity of pellets formed with polyaniline nanoparticles was 17 S／cm．XRD measurements indicated that the polyaniline nanoparticles were crystalline．The cyclic voltammogram of polyaniline naoparticles on powder microelectrode showed good electrochemical properties．