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Study on Synergistic Mechanism of Inhibitor Mixture Based on Electron Transfer Behavior

View Article: PubMed Central - PubMed

ABSTRACT

Mixing is an important method to improve the performance of surfactants due to their synergistic effect. The changes in bonding interaction and adsorption structure of IM and OP molecules before and after co-adsorbed on Fe(001) surface is calculated by DFTB+ method. It is found that mixture enable the inhibitor molecules with higher EHOMO donate more electrons while the inhibitor molecules with lower ELUMO accept more electrons, which strengthens the bonding interaction of both inhibitor agent and inhibitor additive with metal surface. Meanwhile, water molecules in the compact layer of double electric layer are repulsed and the charge transfer resistance during the corrosion process increases. Accordingly, the correlation between the frontier orbital (EHOMO and ELUMO of inhibitor molecules and the Fermi level of metal) and inhibition efficiency is determined. Finally, we propose a frontier orbital matching principle for the synergistic effect of inhibitors, which is verified by electrochemical experiments. This frontier orbital matching principle provides an effective quantum chemistry calculation method for the optimal selection of inhibitor mixture.

No MeSH data available.


Electron density differences and Mulliken charges of the two O atoms in polyoxyethylene chain of OP molecule which is near benzene ring (a), benzene ring (b) of OP molecule, imidazoline ring and aminoethyl (c) and benzene (d) in IM molecule.
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f3: Electron density differences and Mulliken charges of the two O atoms in polyoxyethylene chain of OP molecule which is near benzene ring (a), benzene ring (b) of OP molecule, imidazoline ring and aminoethyl (c) and benzene (d) in IM molecule.

Mentions: Figure 3 shows the electron density difference and Milliken charges of the active groups in OP and IM molecules before and after mixture. It is seen that when OP molecule adsorbs on Fe(001) surface, oxygen atoms in polyoxyethylene chain donate electrons obviously (Fig. 3(a)) whereas the benzene ring obtains a small amount of electrons (Fig. 3(b)). After mixture, oxygen atoms in polyoxyethylene chain of OP molecule lose more electrons, while there is no significant change in the amount of electrons of benzene ring. In other words, OP molecule donates more electrons after mixing with IM.


Study on Synergistic Mechanism of Inhibitor Mixture Based on Electron Transfer Behavior
Electron density differences and Mulliken charges of the two O atoms in polyoxyethylene chain of OP molecule which is near benzene ring (a), benzene ring (b) of OP molecule, imidazoline ring and aminoethyl (c) and benzene (d) in IM molecule.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5037402&req=5

f3: Electron density differences and Mulliken charges of the two O atoms in polyoxyethylene chain of OP molecule which is near benzene ring (a), benzene ring (b) of OP molecule, imidazoline ring and aminoethyl (c) and benzene (d) in IM molecule.
Mentions: Figure 3 shows the electron density difference and Milliken charges of the active groups in OP and IM molecules before and after mixture. It is seen that when OP molecule adsorbs on Fe(001) surface, oxygen atoms in polyoxyethylene chain donate electrons obviously (Fig. 3(a)) whereas the benzene ring obtains a small amount of electrons (Fig. 3(b)). After mixture, oxygen atoms in polyoxyethylene chain of OP molecule lose more electrons, while there is no significant change in the amount of electrons of benzene ring. In other words, OP molecule donates more electrons after mixing with IM.

View Article: PubMed Central - PubMed

ABSTRACT

Mixing is an important method to improve the performance of surfactants due to their synergistic effect. The changes in bonding interaction and adsorption structure of IM and OP molecules before and after co-adsorbed on Fe(001) surface is calculated by DFTB+ method. It is found that mixture enable the inhibitor molecules with higher EHOMO donate more electrons while the inhibitor molecules with lower ELUMO accept more electrons, which strengthens the bonding interaction of both inhibitor agent and inhibitor additive with metal surface. Meanwhile, water molecules in the compact layer of double electric layer are repulsed and the charge transfer resistance during the corrosion process increases. Accordingly, the correlation between the frontier orbital (EHOMO and ELUMO of inhibitor molecules and the Fermi level of metal) and inhibition efficiency is determined. Finally, we propose a frontier orbital matching principle for the synergistic effect of inhibitors, which is verified by electrochemical experiments. This frontier orbital matching principle provides an effective quantum chemistry calculation method for the optimal selection of inhibitor mixture.

No MeSH data available.