Conformal formation of a rigid aromatic polymer on a porous surface responsible for excellent anti-corrosion and self-healing properties of aluminum alloys

Despite the significant development of multilayer composite materials for numerous applications, controlling their growth on stationary platforms for optimal corrosion protection and self-healing remains challenging. In this study, a rigid conjugated aromatic polymer, polysulfone (r-PSU), was coated onto a porous inorganic layer of Al₂O₃/V₂O₅ (P-IL Al/V) containing abundant oxygen vacancies and defects (r-PSU@P-IL Al/V) via plasma electrolysis (PE) and static conversion (SC). The organic layers grew on the solid inorganic platform via non-covalent and covalent bonds to afford r-PSU mats with two-dimensional morphology. Electrochemical impedance spectroscopy (EIS) measurements of r-PSU@P-IL Al/V in a 3.5 wt% NaCl solution demonstrated its excellent corrosion protection (inhibition efficiency for 99.97% in 3 g r-PSU) owing to the synergistic effect of the hydrophobic in r-PSU and the physical barrier of the PE coating. Upon mechanical scratch on the surface, the layer shows excellent self-healing ability upon heating at 200 °C for 4 h owing to the rapid reparability of the r-PSU polymer. An approach of this self-healing phenomenon on a porous surface system suggested in this study will provide a new way for constructing high-performance self-healing organic–inorganic materials.