Tunable electrochemical performance of polyaniline coating via facile ion exchanges

Polyaniline (PAni) was electropolymerized on stainless steel (SS) surface using sulfates (sulfuric acid, SA and p-toluene sulfonic acid, p-TSA) as doping anions. These dopant anions were electrochemically exchanged to phosphates (phosphoric acid, PhAc and phytic acid, PA) to enhance the electrochemical performance of the polymer.

Affecting the anticorrosion performance

The anion exchange was studied by studying the number of redox sites accessible in the polymer during the exchange. The dopants used for polyaniline was substantially affecting the anticorrosion performance of the coating depending on type of dopants, size and their alignment in polymeric chain.

The protection efficiency was significantly improved when sulfates were exchanged to phosphates due to their inhibiting properties towards corrosion for stainless steel.

The study can be found in Progress in Organic Coatings, Volume 136.