A 'Smart' Corrosion-Inhibiting Pigment Based on a Chemical Reaction

摘要

Results show that a solid corrosion inhibitor composed of a mixture of permanganate-containing hydrotalcite and environmentally benign Cr(III) oxide potentially forms the key component of a 'smart' corrosion protective paint. In the presence of a neutral electrolytic environment the solid inhibitor releases the permanganate through an ion exchange mechanism. The permanganate then reacts with the Cr(III) oxide to form soluble Cr(VI) compounds. The activity of Cr(VI) in the aqueous phase slows the oxygen reduction half of the corrosion reaction, thereby inhibiting corrosion. A paint made from this pigment would contain no hazardous hexavalent chromium unless it is exposed to a corrosive environment.