Structure design and properties of MXene-WPU-Co/C electromagnetic shielding composite films

Excess electromagnetic radiation generated during the operation of electronic equipment does not only interfere with the normal operation of precision electronic instruments, but also endangers the human health. Most of the available electromagnetic shielding materials function via reflection mechanism, which can lead to serious secondary electromagnetic waves pollution. Herein, MXene-WPU-Co/C multilayer composite films with controllable thickness and reflectivity have been prepared using Co/C magnetic particles mixed with environmentally friendly waterborne polyurethane (WPU) as the electromagnetic wave absorbing layer and MXene (Ti3C2Tx) as the conductive layer. Remarkably, an electromagnetic shielding efficiency of 31 dB was achieved in the X-band with a reflectivity (R) of 0.01 and enhanced absorption capacity (SEA/SET =99%) when the thickness of the MXene-WPU-Co/C-10 film was 0.2 mm and the mass fraction of MXene was only 10%. Compared with similar electromagnetic shielding materials, this novel low-cost and controllable design strategy affords extremely excellent performances, high efficiencies, and low reflections of electromagnetic shielding films.