Detection and Inhibition of Refractory Steel Corrosion by Rhodamine-Based Compound

A rhodamine-based fluorescent compound, spiro[1H-isoindole-1,9′-[9H]xanthen] -3(2H)-one, ′,6′-bis(diethylamino)-2-[(1-methylethylidene)-amino] (RB1), is developed to detect and inhibit the refractory steel corrosion in 3% NaCl solution. The inhibition effect was evaluated by electrochemical measurements. RB1 suppresses the cathodic corrosion reaction and shifts the corrosion potential toward more negative values. RB1 exhibits a turn-on fluorescence emission in the presence of Fe 3+ ions. The selectivity of RB1 over other commonly coexistent Cu2+, Fe 2+ and Mn2+ was investigated. The variation of the fluorescence intensity is correlated to that of weight-loss. RB1 has a potential application as corrosion inhibitor and corrosion indicator in some industry process.