Layer-by-Layer Polyelectrolyte/Inhibitor Nanostructures for Metal Corrosion Protection

Abstract

Multicomponent coating formed by polyelectrolyte multilayers opens new opportunities for anticorrosion protection. Here we demonstrate a novel method of corrosion protection based on formation and deposition of polyelectrolyte multilayers on aluminum and steel alloys, analysis of different polyelectrolyte compositions (strong−strong, strong−weak, weak−weak) as candidates for corrosion protective layers. The multilayer nanonetwork exhibits very high corrosion protection because of the nature and versatility of the polyelectrolyte complex. The anticorrosion activity of the coating is based on the following mechanisms: (1) pH buffer formed by polybase and polyacid complex suppress pH changes caused by corrosion degradation; (2) coating regeneration and defect elimination due to relative mobility of polymer chains in swollen state; (3) polyelectrolyte layers form a carrier for inhibitor allowing its release on demand; (4) polyelectrolyte nanonetwork provides a barrier between surface and environment. We optimize the coating preparation conditions in a rational way by applying various polyacid−polybase combinations. We use the scanning vibration electrode technique to characterize corrosion protection of the novel coating.