Advancing anti-corrosion performance of composite coating: Self-aligned fluorinated graphene for multifunctional electronic packaging

Abstract

Fluorinated graphene (FG) is considered an ideal filler for polymer nanocomposites to enhance anti-corrosion performance due to its hydrophobicity and electrical insulation properties. A key objective in advanced anti-corrosion design is to create a structure where FG sheets are stacked and aligned, forming an ultra-long, circuitous path to impede the diffusion of active corrosion species. Additionally, integrating aligned FG sheets with polymers prevents the formation of electrical percolation paths, making the coating suitable for electronic passivation. However, achieving a high degree of alignment of FG within the polymer matrix has been a challenge. In this study, we employ a straightforward electrophoretic deposition method to align FG sheets in a polyurethane (PU) matrix for anti-corrosion coatings on copper. The optimized coating exhibits outstanding corrosion resistance for copper, with a stable corrosion rate of 4.0 × 10−3 μm/year in a 3.5 wt% NaCl solution. Moreover, the FG composite coating significantly enhances thermal conductivity, increasing it by 97 % compared to pristine PU, while also providing high electrical resistance. This results in a high breakdown electric field of 28 kV/cm and an extremely low current density of 1.32 × 10−8 A/cm2, which is advantageous for electronic packaging. This multifunctional coating meets industrial standards for large-scale production, uniformity, and controllable thickness, offering a promising approach to improving anti-corrosion protective coatings.