2-(2-Pentadecyl-4, 5-dihydro-1H-imidazol-1-yl)ethanol as a sustainable inhibitor for copper corrosion in molten hydrated phase change materials

摘要

An imidazoline derivatives, 2-(2-pentadecyl-4, 5-dihydro-1H-imidazol-1-yl)ethanol (PDIE) was synthesized with the help of microwave radiation and its inhibiting effect on copper corrosion was investigated in phase change materials (PCM) melts by using gravimetric measurements, electrochemical techniques and quantum chemical calculations. Results show that the addition of PDIE inhibitor greatly decreases the mass transportation at Cu/PCM interface and reduces the corrosion rate of copper by adsorbing on the copper surface. As the concentration of studied inhibitor reaches to the optimal 0.5 mM, the inhibition efficiency is maximized, reaching over 70% at 333 K. Thermodynamic analysis indicates that the adsorption process of PDIE molecule is a mixed physisorption and chemisorption obeying Langmuir isotherm. Surface screening shows that the inhibited copper remains almost morphologically intact and the presence of PDIE compounds on copper surface are confirmed by XPS, EDS and ITIR detections. Local reactivity analysis reveals that the imidazoline ring and heteroatoms are the active sites of PDIE molecule. The corrosion inhibition mechanism is provided through both experimental tests and theoretical studies. (C) 2020 Elsevier B.V. All rights reserved.