NixCoy-C/polyacrylamide hydrogels derived from mixed metal MOF-74 for synergistically enhanced electromagnetic wave absorption and thermal conduction performances

The development of dual-functional composite materials that integrate efficient electromagnetic wave (EMW) absorption and thermal conductivity is a crucial advancement in addressing the issues of electromagnetic pollution and heat accumulation in electronic devices. In this work, Ni x Co y -C/PAM hydrogels derived from mixed metal MOF-74 were successfully fabricated by in situ radical polymerization with the assistance of an external magnetic field. The properties of Ni x Co y -C/PAM were optimized by varying the ratios of cobalt and nickel metals as well as their oxides, thereby providing opportunities for the creation of advanced electromagnetic wave absorbers. When the Ni/Co ratio was increased to 1:1, Ni 1 Co 1 -C/PAM demonstrated superior EMW absorption performance at a filler ratio of 3 wt%. This configuration exhibited a minimum reflection loss of −57.8 dB at 8.64 GHz with a thickness of 3.6 mm, alongside an effective absorption bandwidth extending up to 5.81 GHz with a thickness of 2.3 mm. Furthermore, magnetic orientation within the filler facilitated enhanced heat transfer by establishing high-efficiency thermal conductive pathways. This study offers valuable insights into designing polymer composites characterized by improved thermal conductivity and robust EMW absorption capabilities.