Flexible Composite Films of Modified Carbon Nanotubes/MXene-Aramid Nanofibers with Electromagnetic Interference Shielding and Electrical Heating Performance

Motivated by the advancement of 5G communication technology, electronic devices encounter the challenge of performance fluctuations when exposed to multiband electromagnetic radiation and subjected to temperature variations. Aiming at the problem of limited performance of single-component materials, this paper proposes a design strategy for synergistically enhanced composite films. Through the collaborative action of multiple components and modulation of multidimensional architectures, the performance limitations of functional materials are overcome. Caffeic acid (CA) is employed to modify the surface of multiwalled carbon nanotubes (MWCNTs), and a three-dimensional interconnected conductive network is assembled with MXene nanosheets. Through the hydrogen-bond interfacial strengthening effect, combined with aramid nanofibers (ANF) as the matrix, CA-MWCNTs/MXene-ANF composite films are prepared. This composite film retains excellent mechanical properties with a tensile strength of 49.5 MPa and an elongation at break of 6.4%, exhibits an electromagnetic shielding effectiveness of 46 dB in the X-band, and possess a rapid electrothermal response capability, achieving a temperature increase from room temperature (25 °C) to 169 °C within 10 s when powered by a low voltage of 3 V. It overcomes the performance limitations resulting from the nonuniform dispersion of conventional fillers and poor interfacial adhesion. These advantages endow it with significant potential in diverse fields such as smart wearables, aerospace engineering, flexible electronics, and medical applications.