Superior and durable graphene-based composite coatings by bioinspired interfaces and alignment

Abstract

Graphene (G) has spectacular impermeability and chemical stability, holding promise as an excellent anticorrosion filler, and previous studies supports this hope. However, G only shows limited corrosion inhibition and even corrosion enhancement due to its inherent conductivity and uncontrolled distribution. Natural nacre provides an inspiration for constructing highly aligned structure coatings, in which G sheets are spatially isolated and keep 2D states. To realize the reliable and complete passivation, here we fabricate a nacre-like composite coating through functional G (aG) sheets and epoxy resin by interfaces and alignment designs. The relationship between alignment and properties as electrical conductivities, barrier properties, and impedance modulus is comprehensively compared and discussed. The parallel orientation of aG sheets not only increases the tortuosity to the diffusion paths of aggressive species but also reduces the electrical conductivity of coating in the direction to the electrons transfer, resulting in stability and durability of coating. Our work provides an insight on how to construct high-performance and durable G-based composite coatings by interfaces and structure designs in the future.