Hydrogen and DA bond-based self-healing epoxy-modified polyurea composite coating with anti-cavitation, anticorrosion, antifouling, and strong adhesion properties

Cavitation, corrosion, and fouling are critical factors that significantly impact the performance of power components in large cargo ships. To address these issues, a composite coating called epoxy-modified polyurea (PUE-FD) has been developed with reproducible self-healing properties. The incorporation of functionally reduced graphene oxide (FrGO) with multiple hydrogen bonds in the coating led to a notable increase of 5.6 MPa in the tensile strength of PUE-FD. This enhancement was accompanied by excellent resistance to cavitation, as evidenced by a mere 2.8 mg mass loss after 60 h of continuous cavitation. Furthermore, the inclusion of FrGO exhibited an exceptional barrier effect, providing PUE-FD with superior corrosion protection. The |Z|0.01Hz value of PUE-FD was 9.01 × 109 Ω cm2 after 15 days of immersion in 3.5 wt% NaCl solution. Additionally, the synergistic effect of 2-octyl-4,5-dichloroisothiazolinone (DCOIT) and FrGO resulted in remarkable antifouling performance, with a bacterial removal rate exceeding 99.4% and a microalgae removal rate of up to nearly 100% for PUE-FD. PUE-FD also demonstrated remarkable photothermal self-healing ability, achieving a self-healing efficiency of 89% within just 60 s of near-infrared irradiation. Moreover, the presence of hydrogen bonds in FrGO contributes to the excellent adhesion properties of PUE-FD, resulting in adhesion strengths of more than 10 MPa on copper, stainless steel, and aluminum surfaces. This work presents new inspirations for the preparation of multifunctional coatings with anti-cavitation, anticorrosion, antifouling, and self-healing properties.