▎ 摘　　要

In this study, the tetraaniline (TA) grafted polyhedral oligomeric silsesquioxane (POSS) giant molecule was synthesized and used as graphene (G) dispersant to prepare a functionalization molecule (POSS-TA-G). Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and ultraviolet visible spectroscopy (UV-Vis) were selected to evaluate the existence form and distribution state of pristine and modified graphene. After that, the epoxy coating with proper POSS-TA-G were coated on the surface of Q235 steel to form a function epoxy composite coating. Electrochemical impedance spectroscopy (EIS) and local electrochemical impedance techniques (LEIS) were chosen to estimate the effect of POSS-TA-G on barrier and self-healing performance of asprepared coating. Results revealed that the POSS-TA intercalated graphene presented a good dispersibility based on the p-p interaction between POSS-TA and graphene. Compared with pristine graphene, the POSS-TA-G displayed a good electroactivity and relatively lower conductivity, which could promote the formation of passivation film and reduce the risk of galvanic corrosion during long-term anti-corrosion process. The addition of 0.5 wt% POSS-TA-G could endow coating with superior anti-corrosion performance, including effective shielding properties caused by well-dispersion graphene and self-healing ability derived from POSS-TA.