Molecular dynamics simulation of the interaction between methyl benzotriazole and Cu2O crystal

In circulating water system, methyl benzotriazole (TTA) is one of the common corrosion inhibitors for copper. But the inhibition mechanisms have not been clearly understood so far. In different number of water molecules, the interaction between TTA and Cu2O (copper surface) was investigated with molecular dynamics (MD) method. The results showed that the MD simulation result with water was more consistent with the experiment results. In different number of water molecules, the sequence of the interaction energies between TTA and Cu2O (001) was E-1 (150H(2)O)>E-1(200H(2)O)>E-1(100H(2)O)>E-1(50H(2)O)>E-1(0H(2)O). The number of water molecules had an important influence on the interaction between corrosion inhibitors and Cu2O crystal. From non-bond energy and pair correlation functions, the interaction energies of the model system were mainly contributed by the non-bond interaction. Strong adsorption could be raised by the Coulomb interaction between the negatively charged functional groups in TTA and the positive copper ions in the Cu2O (001) face, and further interaction between aggressive media and copper could be restricted. So, copper corrosion could be avoided. Chemical bonds and non-bond interactions were formed between TTA and Cu2O (001) in different number of water molecules. Water molecules could not be ignored during the MD simulation, too. The results obtained here may provide theoretical supports for developing new corrosion inhibitors.