Anticorrosion Coating with Heterogeneous Assembly of Nanofillers Modulated by a Magnetic Field
Pengpeng Lü, Xue Fu, Xin Li, Li Xu, Yong Fan, Jie Zhao, Limei Tian, Jiyu Sun, Luquan Ren
Abstract
An anticorrosive coating with randomly distributed passive barriers and regionally enriched active corrosion inhibitors is developed by integrating mica nanosheets (MNSs) and magnetic-responsive core–shell mesoporous nanoparticles with 2-mercaptobenzothiazole (Fe 3 O 4 @mSiO 2 /MBT) under magnetic field incubation. The bottom enriched Fe 3 O 4 @mSiO 2 /MBT rapidly releases the MBT to form a passivation layer on corrosion sites, enhancing the corrosion inhibition efficiency by 30.36% compared with the control (NP 0.7 EP-R). The impedance modulus | Z | 0.01 Hz of the sample (NP 0.7 /MNS 0.5 /EP) increases by five orders of magnitude compared with that of its control (NP 0.7 /MNS 0 EP) after 30 days of corrosion immersion. NP 0.7 /MNS 0.5 /EP exhibited the lowest corrosion rate (3.984 × 10 –5 mm/year) as compared to the other samples. Notably, the coating in a fractured state still maintains superior corrosion inhibition even after 40 day salt spray testing. The differentiated distribution of nanofillers was well confirmed by optical microscopy and SEM-EDS, and the synergistic effect of the active/passive integrated anticorrosive coating with merits of both comprehensive protection and fast responsiveness was systematically explored.