Ultrathin, Strong, and Highly Flexible Ti₃C₂T_<i>x</i> MXene/Bacterial Cellulose Composite Films for High-Performance Electromagnetic Interference Shielding.

Abstract

The fabrication of ultrathin films that are electrically conductive and mechanically strong for electromagnetic interference (EMI) shielding applications is challenging. Herein, ultrathin, strong, and highly flexible Ti₃C₂T_<i>x</i> MXene/bacterial cellulose (BC) composite films are fabricated by a scalable <i>in situ</i> biosynthesis method. The Ti₃C₂T_<i>x</i> MXene nanosheets are uniformly dispersed in the three-dimensional BC network to form a mechanically entangled structure that endows the MXene/BC composite films with excellent mechanical properties (tensile strength of 297.5 MPa at 25.7 wt % Ti₃C₂T_<i>x</i>) and flexibility. Importantly, a 4 μm thick Ti₃C₂T_<i>x</i>/BC composite film with 76.9 wt % Ti₃C₂T_<i>x</i> content demonstrates a specific EMI shielding efficiency of 29141 dB cm² g^-1, which surpasses those of most previously reported MXene-based polymer composites with similar MXene contents and carbon-based polymer composites. Our findings show that the facile, environmentally friendly, and scalable fabrication method is a promising strategy for producing ultrathin, strong, and highly flexible EMI shielding materials such as the freestanding Ti₃C₂T_<i>x</i>/BC composite films for efficient EMI shielding to address EMI problems of a fast-developing modern society.