Characteristics of polyaniline synthesized in phosphate buffer solution

Polyaniline (PAni) was synthesized from aqueous phosphate buffer solution (1.7 ⩽ pH ⩽ 2.2) containing 0.1 mol l−1 aniline, electrochemically on a platinum electrode and chemically using ammonium persulfate as oxidant agent. The polymers obtained were characterized by electrochemical response, UV–vis and IR spectrocopies, conductivity measurements and morphological analysis. In general, the polymer growth rate and the characteristics of the polymeric materials are similar to those prepared in sulfuric acid medium. However, phosphate medium presents as advantage the formation of phosphate layers interpenetrated with PAni on active metallic surfaces like steels, aluminum and aluminum alloys, with a wide range of application in corrosion protection.