화학공학소재연구정보센터
Journal of Applied Electrochemistry, Vol.50, No.8, 835-849, 2020
Inhibiting property of nitrite intercalated layered double hydroxide for steel reinforcement in contaminated concrete condition
A nitrite intercalated layered double hydroxide (LDH-NO2) was suggested as an intelligent corrosion inhibitor to provide smart corrosion protection triggered by aggressive ions. A comparison of the inhibiting properties between NaNO2 and LDH-NO2 in the gradually contaminated concrete pore solution was investigated using electrochemical impedance spectroscopy, Mott-Schottky analysis and X-ray photoelectron spectroscopy. The results show that LDH-NO2 exhibits better long-term inhibition performance, and the aggressive ion thresholds for inducing corrosion are 0.1, 0.4, and 0.8 wt% in the blank, NaNO2, and LDH-NO2 solutions, respectively. The reason for this excellent inhibition efficiency is that nitrites can release in time and on demand from the LDH, preventing the corrosion nucleation and metastable pitting corrosion of steel reinforcement caused by chlorides. Graphic abstract LDH-NO2 exhibits better long-term inhibition performance when compared with NaNO2. The reason for this excellent inhibition efficiency is that nitrites can release in time and on demand from the LDH, preventing the corrosion nucleation and metastable pitting corrosion of steel reinforcement caused by chlorides.