Dual-functional microcapsule-engineered epoxy coatings for synergistic thermal management and corrosion protection

To address the limitations of traditional organic coatings low thermal conductivity and inadequate thermal management effect, this study developed novel thermally conductive phase change anticorrosion coatings (PS-x/EP) based on paraffin@silica (Pn@SiO 2 ) microcapsules. The Pn@SiO 2 microcapsules were prepared by interfacial polymerization with the optimal preparation parameters identified, high encapsulation efficiency (E = 85.53 %), phase change enthalpy (ΔH m  = 154.93 J/g) and high thermal conductivity (0.355 W/ (m.K)) were obtained. The thermal conductivity of the composite coatings was increased by up to 54.9 % compared to the epoxy coating (EP) through local thermal conduction pathways formed by the Pn@SiO 2 microcapsules. Moreover, the phase transition of paraffin (Pn) effectively buffered temperature fluctuation and reduced temperature of the coatings. Electrochemical impedance spectroscopy (EIS) and salt spray test results demonstrated that the composite coatings containing within 20 % filler-maintained superior anti-corrosion performance, with |Z| 0.01 Hz of the PS-1/EP (5 %) coating maintained 2.15 × 10 9  Ω∙cm 2 after 30-days immersion in 3.5 % NaCl solution. This work provides a new strategy for the development of thermally conductive anti-corrosion coatings that with efficient thermal management and anticorrosion properties, offering potential for applications requiring dual-functional regulation.