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

• Published in: Journal of materials chemistry. C, Materials for optical and electronic devices Materials for optical and electronic devices, 2023-01, Vol.11 (4), p.1381-1392
• Main Authors: Qin, Ling, Liu, Cui, Zhang, Jixiang, Xi, Min, Pi, Shuai, Guo, Wei, Li, Nian, Zhang, Shudong, Wang, Zhenyang
• Format: Article
• Language: English
• Subjects: Composite materials; Electrical resistivity; Electromagnetic interference; Electromagnetic shielding; Electronic devices; Electronic equipment; Ferric oxide; Heat; Iron oxides; Miniaturization; Multi wall carbon nanotubes; Phase change materials; Phase transitions; Polyvinylidene fluorides; Sandwich structures; Spinning (materials); Superhigh frequencies; Synergistic effect; Thermal conductivity; Transition temperature
• ISSN: 2050-7526; 2050-7534
• DOI: 10.1039/d2tc04381e

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/Fe 3 O 4 ) magnetic spinning films were the top and bottom layers. Due to the multiple synergistic effects among the sandwich structure, carbon materials, Fe 3 O 4 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. A sandwich-type phase change composite shows dynamic electromagnetic shielding performance with a change in temperature and its electromagnetic shielding performance significantly improved after reaching the phase change temperature.