Multiscale Lamellar Regulation of Three-Dimensional Graphene-like Nanostructures for Electromagnetic Interference Shielding and Thermal Management

Two-dimensional (2D) carbon nanomaterials feature exceptional properties, yet practical applications are challenged by poor interlayer connections, leading to suppressed electrical and thermal conductivity. To address this, constructing three-dimensional (3D) carbon nanonetworks is proposed to optimize interlayer interactions. In this study, a multiscale lamellar regulation (MLR) strategy is introduced for creating self-supporting 3D nanoarchitectures from polymeric precursors. The method is initiated with the construction of a 3D polymer network via an ultrasound-assisted freeze-drying (UAFD) process. Ultrasound application refines the lamellar structure by reducing the ice crystal sizes during freezing. Graphitization then further decreases the number of layers and forms interconnected graphitic crystals, leading to the formation of 3D nanostructures composed of continuous 2D nanosheets. This demonstrates the effectiveness of MLR in producing macroscopic-scale nanomaterials without graphene oxide or reduced graphene oxide precursors, cross-linking agents, or additional modification processes. MLR effectively controls the thickness of polymer laminates at submicrometer and nanoscale levels, resulting in a 3D graphene-like nanostructure (GUAFD) with superior electrical, thermal conductivity, and mechanical properties. GUAFD's continuous graphitic membranes form a supportive network, showing promise in EMI shielding and thermal management applications. Meanwhile, it can be used as a thermally conductive electromagnetic wave absorbing material for central processing units, graphic processing units, and power modules in electronic devices.