Corrosion inhibition effect of zeolitic imidazolate framework in chloride-contaminated cement pore solution under elevated temperatures

The elevated temperature significantly influences the adsorption behavior of corrosion inhibitors, and subsequently reduces its inhibition efficiency for the reinforcement. In this study, the inhibition effect of novel zeolitic imidazolate framework (ZIF-8) corrosion inhibitor on the reinforcement under the elevated temperature (from 25 degrees C to 55 degrees C) was extensively investigated in simulated cement pore solution (SPS) by electrochemical measurement together with SEM observation and Raman analysis. The thermodynamic and kinetic parameters for corrosion reaction of the reinforcement were also calculated. At 25 degrees C, ZIF-8 corrosion inhibitor efficiently reduced corrosion rate of the reinforcement in SPS, exhibiting very high inhibition efficiency. Higher activation energy (E-a) for corrosion reaction was relevant to ZIF-8 containing specimen, indicating that the corrosion rate of the steel was significantly accelerated in SPS with ZIF-8 under the elevated temperature. ZIF-8 corrosion inhibitor still halted corrosion of the steel under elevated temperatures; however, unstable adsorption and agglomeration of ZIF-8 was relevant at the elevated temperature. As a result, its inhibition efficiency was significantly reduced from 87.8% at 25 degrees C to only 18.7% at 55 degrees C.