The popularity of intelligent and highly integrated electronic products has led to increasing electromagnetic pollution, which is harmful to the operation of the instrument and to human health. In addition, portable and wearable electronic devices also place requirements on electromagnetic shielding materials that are easy to process, light in weight, small in thickness, flexible, transparent, and highly effective in shielding. Due to its metal conductivity, light weight, high strength, flexibility, and processability, 2D- type carbonitrides ( MXenes ) have shown great potential, however, the basic mechanism of their excellent electromagnetic interference shielding has not been well explained. , Especially when the size of the nanometer scale is much smaller than the typical electromagnetic field wavelength, such as the X -band (8-12 GHz) .     

Achievements

      Recently, Drexel  University ‘s Yury Gogotsi professor and Korea KAIST Sang Ouk Kim and Chong Min Koo well-known in the international journal Advanced Materials published entitled "Electromagnetic Shielding of Monolayer MXene Assemblies" papers. In a wide range of film thicknesses, the report systematically explored the electromagnetic shielding performance of Ti3C2Tx MXene films assembled in two layers .Single MXene mask of the film is about 20% , 24 -layer film thickness of about 55 nm , the shielding rate of 99% (20 is dB) , demonstrating the effectiveness of ultra-high unit thickness ratio  (3.89 × 10 ^{. 6}  dB cm & lt ²  G ^{- 1} ) . A theoretical model was proposed to explain the shielding mechanism below the skin depth, and extended the shielding theory. This lightweight, transparent shielding film is expected to be used in a new generation of portable electronic devices.

Figure 1 Assembly of MXene film .

Figure 2  Effect of heat treatment on MXene film.

Figure 3 Shielding performance of MXene film .

in conclusion

This work demonstrates MXene‘s excellent electromagnetic shielding performance and can revolutionize the next generation of lightweight, portable, and flexible electronics. MXene nanofilms have the potential to replace heavy metal foils or millimeter-thick carbon composites. Theoretical analysis shows that the characteristics of two-dimensional materials have a significant effect on the strong attenuation and multiple reflections of electromagnetic waves. At the same time, the conductivity of micron Ti ₃ C ₂T _x MXene film has exceeded 10,000 S cm ⁻¹ , and more than 30 types of MXene have been found . It is expected to further control the ultra-thin MXene film and propose a solution for industrial preparation of MXene .

Original link:

https://doi.org/10.1002/adma.201906769 

Source: MXene Academic