Electrostatic self-assembly fabrication of multiscale xfMWNT/Co/C@TNF-EP composites with enhanced mechanical and EMI shielding properties

The widespread use of highly integrated smart electronic devices has led to serious electromagnetic pollution, making electromagnetic interference (EMI) shielding materials a crucial solution for controlling electromagnetic radiation. This study utilizes electrostatic self-assembly between negatively charged Co/C@TNF felts and positively charged cetyltrimethylammonium bromide (CTAB) functionalized multiwall carbon nanotubes (fMWNT) to construct a unique three-dimensional (3D) structure within epoxy resin (EP). Due to electrostatic interactions, fMWNT were uniformly loaded on Co/C@TNF felts. These well-dispersed fMWNT serve as bridges, connecting adjacent Co/C@TNF felts and EP, forming a more efficient conductive network, thereby obtaining composites with enhanced mechanical properties and superior EMI shielding effectiveness (EMI SE). The optimized EMI SE of xfMWNT/Co/C@TNF-EP composites reached 54.4 dB, which was 19.3% higher than that of pure Co/C@TNF-EP. Additionally, the flexural properties of the xfMWNT/Co/C@TNF-EP composites were also markedly enhanced, with a flexural strength of 164.40 MPa.