Dielectric synergistic gradient metamaterials enable exceptional ultra–wideband microwave absorption and antibacterial properties

Interface structure design and multi–component strategies for regulating electromagnetic parameters to achieve efficient microwave absorption remain a challenge. In this study, a composite film with a heterogeneous structure, PAN@PPy@Ti₃C₂T_x@GO (PPTG) was fabricated through electrospinning, in situ oxidative polymerization, and dip–coating processes, achieving excellent electromagnetic wave absorption and antibacterial properties. When the filler content is only 20 wt%, the PPTG film exhibits an ultra–wide bandwidth, with a minimum reflection loss value (RLmin) of −49.98 dB (2.2 mm, 16.72 GHz), and the maximum effective absorption bandwidth (EAB) reaches 8.0 GHz (2.5 mm). The outstanding absorption performance is attributed to quarter–wavelength theory, polarization, multiple reflections and scattering, impedance matching, metamaterial properties, quasi–antenna effect, conductive loss, and magnetic loss. Excitingly, the radar cross–section (RCS) of the PPTG film can be reduced by up to 25.72 dB•m², indicating excellent radar stealth properties. Moreover, the PPTG film exhibits excellent antibacterial properties. This research, based on the MXene absorber, provides new insights into the development of lightweight, efficient, and antibacterial microwave–absorbing materials.