Achieving Triple Functionalities in Polyurethane Coatings: The Role of Ti3C2Tx-Mn2O3@Co3O4 Composite Fillers

Abstract

This study reports on a multifunctional composite coating integrating noise reduction, corrosion resistance, and self-healing properties. A Ti₃C₂T_x-Mn₂O₃@Co₃O₄ ternary heterojunction filler was successfully prepared via ultrasound-assisted hydrothermal method. Owing to its semiconductor characteristics and ternary heterostructure, the composite filler exhibits an exceptional photothermal conversion performance, reaching 117.3 °C under 1 W·cm⁻² NIR irradiation. The composite filler was incorporated into a polyurethane matrix to fabricate the functional coating. The composite coating demonstrates outstanding sound absorption performance, with coefficients exceeding 0.6 at frequencies of 6000 Hz and above. Remarkably, it simultaneously achieves approximately 38 dB attenuation of ambient noise under standard testing conditions. Finite element method (FEM) simulations confirm that even the coating with a 2.93% damage ratio achieves a 16.7% reduction in ambient noise under simulated marine conditions. The Ti₃C₂T_x-Mn₂O₃@Co₃O₄ composite filler imparts superior corrosion resistance to the composite coating through its synergistic labyrinth effect and defect filling capabilities. The composite coating maintains an impedance modulus of 3.32 × 10⁹ Ω·cm² after 50 days immersion in 3.5 wt.% NaCl solution. The composite coating also exhibits a rapid self-healing ability within 100 s under 1 W·cm⁻² NIR irradiation through photothermally activated dynamic covalent bond reconfiguration. After multiple damaging-healing cycles, it retains up to 37 dB noise dissipation capacity and |Z|_0.01Hz up to 1.12×10⁹ Ω·cm². With its outstanding noise reduction, corrosion protection, and autonomous damage healing capabilities, this coating shows a tremendous application potential in marine equipment for noise control and corrosion prevention.