The microscopic morphology of highly sulfonated polyaniline

The microscopic morphology of self-doping highly sulfonated polyaniline in water has been investigated by a variety of techniques. The results of transmission electron microscope (TEM), atomic force microscope (AFM), dynamic light scattering (DLS) and viscometry are consistent with the nanometer colloid rather than the real solution. The colloidal particle size varies from 50 nm to 300 nm, depending on the dispersion environment, and the particle is a loose structure composed by spherical particulate with approximately 10–20 nm diameter, which is likely to be composed of a single chain of SPAn. In the low concentration zone, the linear dependence of specific viscosity to concentration has a positive slope and it can be attributed to the colloid dispersion rather than dilute polyelectrolyte solution.