Corrosion inhibition and adsorption behavior of (3-aminopropyl)-triethoxysilane on steel surface in the simulated concrete pore solution contaminated with chloride

Abstract

The absorption behavior of (3-aminopropyl)-triethoxysilane (APS) as a new electrochemical migration reinforcement corrosion inhibitor in different simulated concrete pore (SCP) solutions contaminated with chloride was investigated by electrochemical measurement and surface analysis (X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy and scanning electron microscopy). The effects of temperature and absorption isotherm were investigated to determine the interaction between APS and the steel surface. In uncarbonated saturated Ca(OH)2 SCP solution, APS is mainly physically absorbed on the steel, while chemical absorption and physical absorption probably occur simultaneously in carbonated SCP solution containing NaHCO3/Na2CO3. The surface analysis confirmed that APS can absorb on the steel surface through N atoms and higher N 1s binding energy of APS in NaHCO3/Na2CO3 SCP solution suggests that there may be coordination bonds. The different absorption mechanisms of APS on reinforcement surface in various SCPs can explain the varying inhibition efficiency and stability of APS in medium with different alkalinity.