Vertically Aligned Recycled Carbon Fibre/MXene Composites for Impedance‐Regulated Microwave Absorption and Thermal Management

ABSTRACT Recycled carbon fibres offer a promising sustainable route to functional composites, but their short length and disordered connectivity limit controlled electromagnetic and thermal transport. Here we use electrostatic flocking to construct vertically aligned rCF@Ti 3 C 2 T x /NiFe 2 O 4 arrays within a polydimethylsiloxane (PDMS) matrix inspired by the hierarchical host–symbiont of marine sponges. The aligned architecture redistributes conductive pathways and interfacial polarization, improving impedance matching while providing through‐plane heat transport channels. Compared with the randomly dispersed composite, the vertically aligned composite at the same loading ratio deepens the minimum reflection loss (RL min ) from −33.62 to −60.71 dB. The Effective absorption bandwidth (EAB) broadens increase from 3.91 to 7.82 GHz. In thermal‐transport comparison, vertical alignment raises the through‐plane thermal conductivity from 0.18 to 4.03 W m − 1 K − 1 . These results suggest that alignment control is an effective route to upcycle short recycled fibres into multifunctional polymer composites.