TY - JOUR
T1 - Understanding the relationship between the structural properties of three corrosion inhibitors and their surface protectiveness ability in different environments
AU - Alareeqi, Seba
AU - Bahamon, Daniel
AU - Nogueira, Ricardo P.
AU - Vega, Lourdes F.
N1 - Funding Information:
This work has been partially financed by ADNOC Gas Processing and its stakeholders (Shell, Total and Partex) through the Gas Research Center (project GRC-2017-005) and Khalifa University of Science and Technology (project RC2-2019-007). Support from Dr. Sergio Martinez, from the Scientific Computing Support Department at Khalifa University, and computational time from the HPC at Masdar Institute and the RICH Computational laboratory at Khalifa University, are gratefully acknowledged.
Funding Information:
This work has been partially financed by ADNOC Gas Processing and its stakeholders (Shell, Total and Partex) through the Gas Research Center (project GRC-2017-005) and Khalifa University of Science and Technology (project RC2-2019-007). Support from Dr. Sergio Martinez, from the Scientific Computing Support Department at Khalifa University, and computational time from the HPC at Masdar Institute and the RICH Computational laboratory at Khalifa University, are gratefully acknowledged.
Publisher Copyright:
© 2020 Elsevier B.V.
PY - 2021/3/15
Y1 - 2021/3/15
N2 - All-atom molecular simulations and chemical quantum calculations were used to understand the effect of the environment on the surface adsorption of corrosion inhibitor (CI) molecules. Three CIs abbreviated: TEPA, iTEPA and HC-iTEPA studied in this work, were selected to systematically investigate the influence of the alkyl tail, N-pendant group, imidazoline and benzene rings, on the CIs adsorption behavior. A relationship is provided between their structural properties and their surface protectiveness ability in different environments. Chemical quantum calculations revealed the electron distribution in inhibitors structures, indicating their ability to accept/donate charges from the Fe atoms in vacuum and in water solvation. The quantum molecular parameters in water solvation anticipated higher electron transfer ability of iTEPA in aqueous conditions compared to TEPA and iTEPA, thus, leading to stronger adsorption on iron surface, corroborated by the molecular dynamics (MD) classical simulations. MD simulations showed that nearly 53%, 39%, 59% reduction in adsorption energies was detected for single inhibitor molecule of TEPA, iTEPA, and HC-iTEPA shifting from water to CO2-saline media, respectively. The formation of water double adsorption layer contributed to decreasing the CIs adsorption energies by the larger surface separation distances spotted in the density profiles. Nevertheless, the multi-inhibitors study revealed strong adsorption of TEPA and iTEPA on the iron surface, while HC-iTEPA neglected cooperative adsorption and aggregated as a spherical-like micelle with lower surface coverage propensity. Radial distribution functions g(r) explored the preferential interactions of inhibitor-H2O and inhibitor-CO2 that guided the CIs adsorption conformation. Self-diffusivity coefficients of competing adsorbates with the three CIs were found to be one to two orders of magnitude lower near the interface than in the bulk.
AB - All-atom molecular simulations and chemical quantum calculations were used to understand the effect of the environment on the surface adsorption of corrosion inhibitor (CI) molecules. Three CIs abbreviated: TEPA, iTEPA and HC-iTEPA studied in this work, were selected to systematically investigate the influence of the alkyl tail, N-pendant group, imidazoline and benzene rings, on the CIs adsorption behavior. A relationship is provided between their structural properties and their surface protectiveness ability in different environments. Chemical quantum calculations revealed the electron distribution in inhibitors structures, indicating their ability to accept/donate charges from the Fe atoms in vacuum and in water solvation. The quantum molecular parameters in water solvation anticipated higher electron transfer ability of iTEPA in aqueous conditions compared to TEPA and iTEPA, thus, leading to stronger adsorption on iron surface, corroborated by the molecular dynamics (MD) classical simulations. MD simulations showed that nearly 53%, 39%, 59% reduction in adsorption energies was detected for single inhibitor molecule of TEPA, iTEPA, and HC-iTEPA shifting from water to CO2-saline media, respectively. The formation of water double adsorption layer contributed to decreasing the CIs adsorption energies by the larger surface separation distances spotted in the density profiles. Nevertheless, the multi-inhibitors study revealed strong adsorption of TEPA and iTEPA on the iron surface, while HC-iTEPA neglected cooperative adsorption and aggregated as a spherical-like micelle with lower surface coverage propensity. Radial distribution functions g(r) explored the preferential interactions of inhibitor-H2O and inhibitor-CO2 that guided the CIs adsorption conformation. Self-diffusivity coefficients of competing adsorbates with the three CIs were found to be one to two orders of magnitude lower near the interface than in the bulk.
KW - CO– saline aqueous solutions
KW - Corrosion inhibitors
KW - Imidazoline-based molecules
KW - Iron surface adsorption
KW - Micelle structure - aggregation
KW - Molecular dynamics and DFT calculations
UR - http://www.scopus.com/inward/record.url?scp=85097342228&partnerID=8YFLogxK
U2 - 10.1016/j.apsusc.2020.148600
DO - 10.1016/j.apsusc.2020.148600
M3 - Article
AN - SCOPUS:85097342228
SN - 0169-4332
VL - 542
JO - Applied Surface Science
JF - Applied Surface Science
M1 - 148600
ER -