Electromagnetic interference (EMI) shielding films with excellent mechanical properties are highly promising for applications in flexible devices, automotive electronics and aerospace. Inspired by the excellent mechanical properties of nacre derived from its micro/nanoscale structure, high-performance MXene/Cellulose nanocrystals (CNC) composite films were prepared by simple solution blending and followed vacuum-assisted filtration process. The presence of CNC significantly improves the mechanical properties with tensile strength increasing from 18 MPa to 57 MPa and toughness improving from 70 kJ/m ³ to 313 kJ/m ³. Meanwhile, the composite film still exhibits high electrical conductivity (up to 10 ⁴ S/m) and excellent EMI shielding efficiency (over 40 dB) with a small thickness of 8 μm.

CoFe₂O₄ nanofibers with fishbone-like structure were prepared by a electrospinning method followed with high temperature calcination, using polyvinylpyrrolidone (PVP), iron nitrate nonahydrate (Fe(NO₃)₃·9H₂O) and cobalt nitrate hexahydrate (Co(NO₃)₂·6H₂O) as raw materials. Results show that the crystallinity and grain size of nanofibers become larger with increasing calcination temperature. Meanwhile, the surface morphology of CoFe₂O₄ nanofibers changes from smooth to rough and porous. The morphology of CoFe₂O₄ nanofibers exhibits a fishbone-like structure with calcination temperature exceeding 800 ℃. The diameter of the fiber is gradually decreased with the increase of calcination temperature, and the average diameter of CoFe₂O₄ nanofibers calcined at 900 ℃ reaches 80.3 nm. By vibration sample magnetometer (VSM) test, the saturation magnetization (M_s) of CoFe₂O₄ nanofibers increases with the increase of calcination temperature, and the M_s of CoFe₂O₄ nanofibers calcined at 900 ℃ is 87.13 A·m²/kg. In a result of vector network analyzer (VNA) analysis, the microwave absorption performance is significantly different with calcination temperature changing. Among them the fibers calcined at 800 ℃ have the highest wave absorption ability. The microwave absorption mechanism of CoFe₂O₄ nanofibers mainly includes hysteresis loss and eddy current loss. The morphology of porous and fishbone-like generated by calcination can increase the reflection loss, for the reason that this morphology is beneficial for microwave reflection multiple times on the fiber surface.

Ceramic matrix composites (CMCs) are promising candidates for application in aeroengine, aerospace aircraft thermal protection systems, nuclear power system, and other fields. At present, CMCs are developing from structural bearing materials to multi-functional composites. MAX phases are a group of layered ternary ceramics with excellent plastic deformation capacity, high electrical conductivity, good irradiation resistance and ablation resistance. Besides strengthening and toughening CMCs, the introducing MAX phases into CMCs can effectively improve the anti-irradiation, anti-ablation and electromagnetic interference shielding performance, meeting requirements of multi-functional CMCs. This paper reviewed the progress on MAX phases modified CMCs, design mechanism and application prospect.

In recent years, ternary layered carbide/nitride MAX phases and their derived two-dimensional nanolaminates MXenes have attracted extensive attention. The crystal structure of MAX phase is composed of M_n+1X_n unit interleaved with layers of A element. MAX phases combine good properties of metal and ceramic, which makes them promising candidates for high temperature structural materials, friction and wear devices, nuclear structural materials, etc. When etching the A-layer atoms of the MAX phase, the two-dimensional nanolaminates with the composition of M_n+1X_nT_x (T_x is surface termination), i.e. MXene, is obtained. MXenes have wide range of composition, and tunable physical and chemical properties, which endow them great potential in the applications of energy storage devices, electromagnetic shielding materials, and electronic devices, etc. In this paper, the research progress of MAX phase and MXene was introduced in terms of composition and structure, synthesis methods, and properties and application. Furthermore, the research prospects of this large family of materials were discussed.

A novel SiC/C_f composite with SiC array modified coating was prepared by electroless plating combined with high temperature sintering using glucose, Si powder and carbon fiber as raw materials. The phase composition, microstructure and absorbing properties of SiC/C_f composites were characterized by different methods. The results show that the surface of the carbon fiber is coated with a large amount of SiC arrays, which grows outward on the surface of the carbon fiber. The SiC arrays are uniformly distributed and approximately 1.4 μm in height. When the thickness of SiC/C_f composite is about 1-2 mm, with the thickness increasing, the minimum reflection loss (RL_min) moves from high frequency to low frequency. When the absorber thickness is 1.8 mm, the RL_min reaches -40.653 dB at 8.31 GHz and the effective absorption bandwidth (RL < -10 dB) is 1.11 GHz. When the thickness is 1.5 mm, the minimum effective absorption bandwidth can reach 2.42 GHz. Additionally, the RL_min is less than -20 dB when the absorber thickness ranges from 1.3 to 1.8 mm. This new SiC/C_f composite modified by SiC array is expected to be a lightweight and efficient electromagnetic absorbing material.