Polydopamine derived N-doped carbon nanocoatings on Cu oxide cones for enhancing boiling heat transfer performance

Constructing low thermal resistance, durable, and cost-effective thermal interface coatings on metal surface is urgent to solve the thermal management problem of advanced electronics. Herein, N-doped carbon (NC) nanocoatings on Cu oxide cones (NC₆₀₀/CuO_12h@Cu) were prepared by assembly and subsequent pyrolysis of polydopamine (PDA). The surface morphology and chemical components were tailored by varying the etching time in alkaline solution and pyrolysis temperature. SEM, XRD, XPS, TEM, Raman, AFM and contact angle measurements were performed to characterize the morphologies, compositions, and surface wettability. Systematic study disclosed that the boiling heat transfer performance of modified Cu substrate was significantly enhanced in the presence of NC coated Cu oxides. Heat transfer coefficient and critical heat flux of NC₆₀₀/CuO_12h@Cu increased by 197.6 % and 84.7 % in comparison with bare Cu surfaces when the etching time and annealing temperature were 12 h and 600 °C, respectively. The vertically-oriented in-plane heat dissipation direction of NC coating, the abundant nucleation sites and the superhydrophilicity synergistically enhanced the boiling performance. This PDA derived NC coating is assumed to be a promising surface nanoengineering strategy for optimizing the physicochemical properties and micro/nanostructures of metal surface, thus shows potential to improve the interfacial thermal performance for industrial thermal management.