Entanglement Assembly of Graphite Worms: A Direct Strategy to Achieve Highly Crystalline Graphene Foam for Superior Electromagnetic Interference Shielding

Abstract

With the increasing demand for lightweight and high-performance electromagnetic interference (EMI) shielding materials, graphene foams (GFs) have emerged as promising candidates. However, conventional methods relying on graphene oxide or chemical vapor deposition face challenges such as structural defects, high cost, and limited scalability. Herein, we report a facile and scalable strategy for fabricating high-performance GFs directly from natural graphite via a confined expansion process followed by thermal treatment. Notably, this process introduces a novel assembly mechanism based on the spatial confinement-induced entanglement of exfoliated graphite worms, which spontaneously form a stable, self-supporting three-dimensional conductive network. The resulting GF exhibits an ultralow density of ~17.2 mg•cm -³, excellent electrical conductivity of 1.9×10³ S•m -1 , and outstanding mechanical robustness. Remarkably, the GF achieves a superior specific shielding effectiveness (SSE/t) of 19302.3 dB•cm²•g⁻¹, surpassing most reported carbon-based shielding materials. This outstanding performance is attributed to the low-defect nature of the constituent graphene sheets, the long-range interconnected conductive network, and the highly porous architecture. Furthermore, the intermediate gel-like precursor allows arbitrary shaping and patterning, enabling the creation of customized architectures.These features, combined with exceptional flame retardancy and hydrophobicity, make the GF highly suitable for advanced applications in aerospace, wearable electronics, and next-generation communication systems.