Regulating the interfacial properties of GO@pPTFE/EP composite coatings for superior tribological performance and corrosion resistance in simulated deep-sea environment

Abstract

Organic coatings are ideal candidates for mitigating corrosion and mechanical wear of metal-based substrates due to the effective physical barrier capacity in marine environments. However, their performance is often compromised by inherent defects, alternating hydrostatic pressure (AHP), and mechanical wear, ultimately resulting in coating failure and substrate corrosion. This study presented a high-performance composite coating by integrating core-shell nanohybrids (GO@pPTFE) into waterborne epoxy resin matrix. The combination of low surface energy PTFE core and GO nanosheets featuring abundant functional groups not only balanced high hydrophobicity and strong adhesion but also endowed the coating with outstanding corrosion resistance (|Z|_{0.01 Hz} value of 1.04 × 10⁹ Ω·cm² even after 20 cycle of immersion under 20 MPa AHP environment). Furthermore, the resulting coating exhibited stable low coefficient of friction (0.027), excellent anti-wear property (wear rate of 0.96 × 10⁻⁶ mm³·N⁻¹·m⁻¹), narrow wear track width (195 μm), and slight wear tracks. These significant improvements were mainly ascribed to the robust interfacial adhesion, effective barrier properties, robust interfacial adhesion, and synergistic wear reduction effects associated with the constructed GO@pPTFE core-shell nanohybrids, making the coating a promising strategy for deep-sea corrosion and wear challenges.