Construction of Heterostructured PAN@PDA@Ti₃C₂T_<i>x</i> MXene Composite Films for Enhanced Microwave Absorption Performance

MXenes, which are transition metal carbides and nitrides, have great promise for microwave absorption. Nevertheless, these materials have several disadvantages, including impedance mismatch and high density, which are in conflict with the desired characteristics of being thin, lightweight, wide-band, and highly absorbent for microwave-absorption purposes. This work demonstrates the fabrication of extremely thin and light conductive films with a wrinkled structure using a solution deposition method. Polyacrylonitrile (PAN) nanofiber membranes were used as the substrate, and a heterostructure was built through polydopamine (PDA) surface modification. The dipole and interfacial polarization, conduction loss, impedance matching, multiple reflections and scattering, quarter-wavelength, quasi-antennas, hysteresis loss, residual loss, and metamaterial properties enhance the microwave absorption of the samples. Analysis of electromagnetic parameters showed that the PAN@PDA@Ti3C2Tx MXene (PPM) film achieved a minimum reflection loss (RLmin) of −38.30 dB at 16.08 GHz with a thickness of 1.5 mm, and an effective absorption bandwidth (EAB) of 5.68 GHz (thickness of 1.7 mm, frequency range of 11.6–17.3 GHz). Simulation results indicated that the film’s radar cross-section (RCS) could be reduced by up to 27.33 dB·m2. Therefore, the film shows great potential for applications in electromagnetic protection, electronic devices, and aerospace fields.