Sandwich-type phase-change composites with the dual-function of efficient heat management and temperature-regulated electromagnetic interference shielding performance

Abstract

Considering the continuous development of electronic equipment superintegration and miniaturization, difunctional materials that have both effective heat management and electromagnetic interference (EMI) shielding performance are urgently required. Herein, sandwich-type phase change composites (STPCCs) with efficient heat management and temperature-regulated electromagnetic interference shielding performance were designed and prepared through an easy pressing process, in which an expanded graphite (EG)/multi-walled carbon nanotube (MWCNT) hybrid porous scaffold adsorbed the phase-change material eicosane (ES) was the middle layer, and polyvinylidene fluoride/ferric oxide (PVDF/Fe₃O₄) magnetic spinning films were the top and bottom layers. Due to the multiple synergistic effects among the sandwich structure, carbon materials, Fe₃O₄ and ES, the resulting STPCCs displayed high volume conductivity (135 S cm⁻¹) and excellent EMI shielding effectiveness (EMI SE) (98.4 dB). Impressively, above the phase transition temperature of ES, the volume electrical conductivity of STPCCs increased to 146.2 S cm⁻¹, their EMI SE increased to 115.75 dB, and their absorption shielding accounted for 85.2% of the total shielding in the X-band, significantly showing a temperature-regulated EMI shielding performance and outperforming most of the reported the synthetic equivalents. In addition, the obtained STPCCs exhibited excellent thermal conductivity (3.61 W m⁻¹ K⁻¹), exhibiting more effective heat dissipation ability in advanced electronic devices.