Thermally Conductive Phase Change Composites for Wideband Electromagnetic Noise Reduction and Thermal Management

For the advancement of next-generation electronic devices and telecommunication, the development of multifunctional materials integrating electromagnetic (EM) wave attenuation and thermal management is crucial and challenging. In this study, multifunctional poly(dimethylsiloxane) (PDMS)/boron nitride (BN)/carbon nanotubes (CNT) @paraffin wax phase change composites (PBC@W) were developed using a low-cost template method. Thanks to the well-constructed thermally conductive network of multidimensional fillers (two-dimensional BN sheets and one-dimensional CNT) in the PDMS matrix, the PBC@W composites could achieve a thermal conductivity of 1.63 W/m·K while showing a high latent heat of 125 J/g for efficient thermal energy storage. As a result, it can serve as a heat sink to store thermal energy and also stabilize the temperature of electronic devices against thermal shock. Meanwhile, the proven full X-band microwave attenuation performance of over 10 dB (effective attenuation bandwidth >4.2 GHz) at thicknesses less than 3.1 mm provides the devices with effective protection from EM noises. The combination of such thermally conductive features, high latent heat, and wideband EM wave attenuation performance in one material offers an innovative low-profile material solution to alleviate the ever-increasing thermal and electromagnetic interference (EMI) issues in miniaturized high-speed electronic systems.