Superhydrophobic Yet Highly Thermally Conductive BN Composites for Electrical Erosion Resistance

The electrical erosion of outdoor polymer structures is an inevitable phenomenon in a wet-contamination environment, threatening the reliable operation of the power system. The polymer composites with superhydrophobic surfaces or high thermal conductivity are useful for inhibiting the generation and development of electrical erosion. However, the superhydrophobic surfaces of polymer are unlikely to be durably sustained, and lots of thermally conductive inorganic fillers in polymer would cause processing difficulties. Herein, we report superhydrophobic polymer composites containing orientated boron nitride (BN) flakes, which can be easily constructed by photopolymerization-induced phase separation to generate inherently superhydrophobic structures and confined printing thickness-induced BN orientation via digital light processing (DLP) 3D printing. The 3D objects with 50 wt% porogen and 20 wt% BN exhibit a water contact angle of 156° and excellent thermal conductivity of 7.11 W·m ^-1 ·K ^-1 . The superhydrophobic surface of the structural composites can inhibit the adhesion of contaminated liquid and enhance the surface flashover voltage, in which the oriented BN networks can quickly dissipate heat generated by arcing. This study offers an easy avenue and provides some guidance for fabricating functionalized dielectrics for the safe operation of electrical equipment.