Multifunctional Phase Change Composites with Thermal-Shock Resistance and Electromagnetic Wave Absorption for High-Power Electronics

With the ongoing miniaturization and ever-increasing power of electronic devices, overwhelming heat accumulation and electromagnetic-wave (EMW) pollution have become key issues restricting their development. The development of multifunctional materials that integrate efficient thermal management and wideband EMW absorption has attracted much attention and is challenging. Here, polypyrrole aerogel/paraffin wax phase change composites (PCC) were prepared by mild chemical oxidation and subsequent impregnation. Due to the excellent encapsulation effect of the polypyrrole aerogel with a three-dimensional porous structure on paraffin wax, the PCC exhibits good shape stability and cycling stability while processing a high latent heat of 150.4 J g^-1. The PCC shows a substantial average temperature drop of 20.2 °C during thermal shock of 3000 W m^-2 through phase transition heat absorption compared with traditional natural cooling. Meanwhile, the PCC has impressive EMW absorption capacity, with a minimum reflection loss of -29.97 dB and a maximum effective absorption bandwidth of 6.01 GHz at thicknesses less than 2.18 mm, providing effective electromagnetic pollution protection for devices and human bodies. The PCC demonstrates multiple complementary functions through a simple and general manufacturing strategy, offering a viable solution to alleviate the increasing heat and electromagnetic pollution problems in miniaturized high-power electronics.