Polydopamine-assisted silver-coated spherical boron nitride as dual functional filler for thermal management and electromagnetic interference shielding

Developing high-performance multifunctional fillers for polymer filling is of significant importance for thermal management and electromagnetic interference (EMI) shielding in the electrical and electronic fields. In this work, a novel dual-functional filler of silver-coated spherical boron nitride ([email protected]) was first synthesized via the electroless chemical deposition method with the aid of polydopamine and then used to improve the thermal conductivity and EMI shielding performance of the silicone rubber (SR). It is found that the [email protected] filled SR composites show remarkable improvement in thermal conductivity compared to raw s-BN filled composites at the same loading fraction. At 23.3 vol% [email protected], the SR/[email protected] composite exhibits a thermal conductivity of 1.53 W m−1 K−1, which is improved by 48.5 % and 806.8 % compared to the SR/s-BN composite and pure SR, respectively. Meanwhile, the remarkably improved electrical conductivity of the SR/[email protected] composite at 23.3 vol% [email protected] leads to an EMI shielding effectiveness of 20.9 dB that already reaches a commercial standard. Moreover, due to the high sphericity and smooth surface of [email protected], the [email protected] filled SR mixture before curing possesses good processability and thus is suitable for the potting processes. Overall, this work provides a novel strategy for developing polymer composites with both thermal conductivity and EMI shielding properties.