Fabrication of ZnO@Fe2O3 superhydrophobic coatings with high thermal conductivity

Abstract

Efficient thermal management materials are an integral part of electronic devices and can quickly contribute to their heat dissipation, thereby greatly improving their reliability, stability and service life. However, the inherent hygroscopicity of the film surface sets obstacles to the reliability and structural stability of electronic devices. To address these issues, a bionic structural design was obtained by spraying a polyurethane/stearic acid/zinc oxide‑iron oxide composite powder (TPU/STA/ZnO@Fe2O3) on the surface of graphene composite films. At the same time, the graphene composite film has a high in-plane thermal conductivity (up to 533 W−1·m−1·K−1) and is able to reduce the film surface temperature to room temperature within 5 s due to its highly ordered layered design and strong hydrogen bonding interactions. In addition, the composite film offers a range of advantages such as good hydrophobicity and electrical conductivity. With a water contact angle of up to 159.5 ± 2° and an electrical conductivity of up to 3 × 103 S/m in steady state, the results show that the superhydrophobic graphene composite film has good physical, chemical and mechanical stability, as well as self-cleaning capabilities. It also retains good flexibility and reliability under 350 bending cycles. In this regard, the development of graphene composite films with high thermal conductivity, high superhydrophobicity, good electrical conductivity and flexibility is expected to be used as thermally conductive materials, opening up a new path in the field of thermally conductive heat dissipation materials for electronic components.