Functionalized Graphene and Aramid Fiber Synergistically Enhanced Anti-Corrosion and Toughened Epoxy Coating

The corrosion of metal components leads to substantial economic losses and poses serious safety hazards. While organic coatings are regarded as an effective countermeasure, conventional epoxy resins (EPs) often exhibit high brittleness and insufficient corrosion resistance after curing. To overcome these limitations, this study proposes a novel modification strategy. A multilayer graphene-reinforced epoxy composite coating was fabricated via a layer-by-layer spraying process, employing uniformly dispersed modified aramid nanofibers (ANFs) and low-defect graphene as functional fillers. Polydopamine (PDA) was utilized to improve the dispersion of graphene oxide (GO), mitigate defect-associated permeation pathways, and enhance the interfacial bonding between the graphene layer and the epoxy matrix, thereby ensuring coating integrity. Tannic acid (TA) effectively improves the dispersion of ANF within the epoxy, preventing stress concentration. The corrosion resistance and mechanical properties of the composite coating were systematically evaluated. Results demonstrate that the coating achieves a low-frequency impedance of 1.98 × 1010 Ω·cm2. With the incorporation of 0.05% TA-modified ANFs, the elongation at break increases to 68.79%, and the impact resistance is significantly enhanced, with the impact height reaching 50 cm. The composite coating preparation strategy in this work offers a novel approach for constructing multifunctional composite coatings, demonstrating broad application prospects.