Polyaniline Dispersions. 5. Poly(vinyl alcohol) and Poly(N-vinylpyrrolidone) as Steric Stabilizers

When the oxidative polymerization of aniline proceeds in the presence of poly(vinyl alcohol) or poly( N -vinylpyrrolidone), sterically-stabilized polyaniline dispersions are obtained. The particles have an average diameter of about 300−600 nm as determined by dynamic light scattering. The yield of polyaniline in dispersion form often decreased if the reaction mixture was stirred during polymerization and dispersions were then accompanied by a macroscopic precipitate. Poly( N -vinylpyrrolidone) is a more efficient stabilizer compared to poly(vinyl alcohol). Microstructured composites, which contain up to ∼70 wt % of electrically-conducting polyaniline dispersed in an insulating matrix, can be prepared from these dispersions.