Multifunction integration within magnetic CNT-bridged MXene/CoNi based phase change materials

Developing advanced nanocomposite phase change materials (PCMs) integrating zero-energy thermal management, microwave absorption, photothermal therapy and electrical signal detection can promote the leapfrog development of flexible wearable electronic devices. For this goal, we propose a multidimensional collaborative strategy combining two-dimensional (2D) MXene nanosheets with metal-organic framework-derived one-dimensional (1D) carbon nanotubes (CNTs) and zero-dimensional (0D) metal nanoparticles. After encapsulating paraffin wax (PW) in three-dimensional (3D) networked multidimensional MXene/CoNi–C, the resulting composite PCMs exhibit excellent thermal energy storage capacity and long-term thermally reliable stability. Benefiting from the synergistically enhanced photothermal effects of CNTs, Co/Ni nanoparticles and MXene, PW@MXene/CoNi–C can capture photons efficiently and transfer phonons quickly, yielding an ultrahigh photothermal conversion and storage efficiency of 97.5%. Additionally, PW@MXene/CoNi–C composite PCMs exhibit high microwave absorption with a minimum reflection loss of −49.3 ​dB at 8.03 ​GHz in heat-related electronic application scenarios. More attractively, the corresponding flexible phase change film can simultaneously achieve thermal management and electromagnetic shielding of electronic devices, as well as photothermal therapy and electrical signal detection for individuals. This functional integration design provides an important reference for developing advanced flexible multifunctional wearable materials and devices.