Isolated Solid Wall-Assisted Thermal Conductive Performance of Three-Dimensional Anisotropic MXene/Graphene Polymeric Composites.

The introduction of three-dimensional (3D) continuous conformations in polymer materials is a convincing proposal for acquiring the desirable multifunction to fulfill the urgent demands of highly integrated electronic devices. However, the limited functional design of the filled aligned network remains challenging. Herein, directional self-assembly 3D MXene/graphene aerogels are fabricated as conductive networks for polyethylene glycol (PEG) matrix. Based on the uniaxial and biaxial ice template method, the temperature gradient affects the aligned arrangement of the 3D microstructure. The biaxial PEG/MXene/GR composites exhibit an enhanced through-plane thermal conductivity of 1.64 W m-1 K-1 at 10.6 vol % content, which is 522% higher than that of pure PEG. The influence of the biaxial self-assembly strategy compared with that of the uniaxial one on the thermal conductivity reaches the highest 333% when the weight ratio equals 1:1. Meanwhile, the same difference also occurs in the electromagnetic shielding interference (EMI) property. The advanced EMI-shielding effectiveness of the biaxial PM1G1 composites reaches ∼36 dB at the 2.5 mm thickness. This research provides valuable guidance for designing high-performance applications of anisotropic thermal management and EMI shielding in 5G telecommunications and mobile electronic devices.