MIL-88A (Fe) filler with duplicate corrosion inhibitive/barrier effect for epoxy coatings: Electrochemical, molecular simulation, and cathodic delamination studies

• Published in: Journal of industrial and engineering chemistry (Seoul, Korea) 2021, 97(0), , pp.200-215
• Main Authors: Alipanah, Nariman, Yari, Hossein, Mahdavian, Mohammad, Ramezanzadeh, Bahram, Bahlakeh, Ghasem
• Format: Article
• Language: English
• Subjects: Corrosion inhibition; Epoxy coating; MIL-88A; MOF; Molecular simulation; 화학공학
• ISSN: 1226-086X; 1876-794X
• DOI: 10.1016/j.jiec.2021.01.035

[Display omitted] •MIL-88A (Fe) as an MOF based on Fe+3 cations and fumaric acid was fabricated.•The MIL-88A (Fe) showed considerable corrosion inhibition activity for bare steel samples.•The epoxy coatings containing MIL-88A (Fe) showed active inhibition behavior.•Adsorption of released species from MIL-88A (Fe) scaffold was suggested for its active inhibition.•The theoretical (QM, MC/MD) computations were employed to confirm adsorption on steel. The MIL-88A (Fe) as a MOF based on Fe+3 cations and fumaric acid was fabricated as a corrosion inhibitive filler to achieve a protective coating with duplicate active/passive inhibition properties. The polarization test indicated that the MIL-88A (Fe) saline-based extract had an inhibition effect. The formation of an inhibitive layer was seen in the EIS results for the sample immersed in the MIL-88A (Fe) extract. The slight solubility of MIL-88A (Fe) in the water (122.4ppm total organic carbon and 2ppm Fe+3) caused the inhibitive ions' release. The adsorption of release species from MIL-88A (Fe) scaffold on the substrate was confirmed by the theoretical (QM, MC/MD) computations. The EIS and salt spray test results obtained from scratched epoxy coated samples showed the Epoxy-MIL-88A (Fe) coating's active inhibition effect. The pull-off adhesion strength and cathodic delamination resistance were also improved in the presence of MIL-88A (Fe). The adhesion loss of epoxy coatings after 7 days of exposure to the salt spray decreased from 31.4% to 9.4%, respectively. The unscratched samples filled with MIL-88A (Fe) particles showed excellent barrier properties. The breakpoint frequency value declined from 2.4 to 0.8, and the reduction of low-frequency impedance magnitude decreased from 33% to 20%.