Barrier and passivation effects of 2D PANI@JNSs Janus nanosheets in epoxy anticorrosion coating

Abstract

AbstractThe filled sheet‐like inorganic materials can usually improve the anticorrosion performance of the coating. Herein, the Janus nanosheets (JNSs) with two‐dimensional structure were prepared by phase separation method, modified by polyaniline (PANI) on the amino side of JNSs and composited with epoxy resin (EP). Scanning electron microscope (SEM), transmission electron microscopy (TEM), atomic force microscope (AFM), Fourier transform infrared spectroscopy (FT‐IR), thermogravimetry (TG) were used to characterize the morphology and chemical structure of JNSs and PANI@JNSs. The anti‐corrosion performance of coatings was measured by electrochemical impedance spectroscopy (EIS) and salt spray experiment. Compared with pure EP, the |Z|0.01Hz of 0.5%‐JNSs/EP coating and that of 0.5%‐PANI@JNSs/EP coating reached 5.6 × 108 and 5.4× 1010 Ω·cm2 after immersed for 35 days, nearly 2 and 4 orders of magnitude higher than pure EP respectively. The excellent anti‐corrosion performance of 0.5%‐PANI@JNSs/EP coating is due to the synergistic effect of physical barrier effect of PANI@JNSs, interfacial interaction between PANI@JNSs and epoxy resin and passivation effect of PANI. Moreover, PANI@JNSs possess both strengthening and toughening effects on composite coating. Janus nanosheets provide a new idea and method for preparing high‐performance anticorrosive materials.