Binary Strengthening and Toughening of MXene/Cellulose Nanofiber Composite Paper with Nacre-Inspired Structure and Superior Electromagnetic Interference Shielding Properties

TLDR

High‑performance electromagnetic interference shielding materials are widely used to mitigate radiation pollution from electrical communication equipment, but many suffer from large thickness and poor mechanical properties that limit their applications. The study aims to fabricate an ultrathin, highly flexible Ti₃C₂Tₓ/CNF composite paper with a nacre‑like lamellar structure. This is achieved via a vacuum‑filtration‑induced self‑assembly process. The resulting nacre‑like d‑Ti₃C₂Tₓ/CNF composite paper exhibits binary strengthening and toughening, achieving tensile strength up to 135.4 MPa, fracture strain of 16.7 %, folding endurance of 14 260 cycles, electrical conductivity of 739.4 S m⁻¹, and specific EMI shielding efficiency of 2647 dB cm² g⁻¹ at a minimum thickness of 47 µm, making it suitable for flexible wearable devices, weapon equipment, and robotic joints.

Abstract

With the growing popularity of electrical communication equipment, high-performance electromagnetic interference (EMI) shielding materials are widely used to deal with radiation pollution. However, the large thickness and poor mechanical properties of many EMI shielding materials usually limit their applications. In this study, ultrathin and highly flexible Ti3C2Tx (d-Ti3C2Tx, MXene)/cellulose nanofiber (CNF) composite paper with a nacre-like lamellar structure is fabricated via a vacuum-filtration-induced self-assembly process. By the interaction between one-dimensional (1D) CNFs and two-dimensional (2D) d-Ti3C2Tx MXene, the binary strengthening and toughening of the nacre-like d-Ti3C2Tx/CNF composite paper has been successfully achieved, leading to high tensile strength (up to 135.4 MPa) and fracture strain (up to 16.7%), as well as excellent folding endurance (up to 14 260 times). Moreover, the d-Ti3C2Tx/CNF composite paper exhibits high electrical conductivity (up to 739.4 S m–1) and excellent specific EMI shielding efficiency (up to 2647 dB cm2 g–1) at an ultrathin thickness (minimum thickness 47 μm). The nacre-inspired strategy in this study offers a promising approach for the design and preparation of the strong integrated and flexible MXene/CNF composite paper, which may be applied in various fields such as flexible wearable devices, weapon equipment, and robot joints.