Polarity-induced ZnO nanostructure to construct flexible ZnO/rGO@PET fabric with high-efficiency microwave absorption property
摘要
The growing demand for intelligent wearable devices has put forward new challenges for flexible and high-performance microwave-absorbing materials. Traditional powder-based electromagnetic wave absorbing materials are restricted by their rigidity and bulkiness, making them unsuitable for intelligent, flexible wearable devices. Herein, flexible ZnO/rGO@PET composite fabrics were successfully fabricated by choosing polyester knitted fabric as an elastic scaffold and then adhering ZnO/rGO through impregnation and hydrothermal treatment process. The morphology of ZnO presents needle, flake, and coralline-clustered structures, which are regulated by controlling the growth rate of ZnO seeds along the c-axis in a strong polar ion environment. Among them, the flake-like ZnO synthesized in a 0.050 mol/L growth solution exhibits a looser porous structure, which would significantly enhance impedance matching and multiple internal reflections. Furthermore, flake-like ZnO has a higher electric dipole moment, which can provide stronger dipole polarization and interface polarization. Notably, the ZnO/rGO@PET composite fabric with flake-like ZnO achieves the optimal minimum reflection loss (RLmin) of -70.76 dB and an effective absorption bandwidth (EAB) of 4.20 GHz (8.2–12.4 GHz). Furthermore, adjusting the stacking sequence of functional fabric layers could effectively control the electromagnetic parameters and corresponding microwave absorption performance, which is well maintained after repeated washings. This work provides a novel strategy for designing next-generation tunable electromagnetic textiles.