Robust magnetic carbon nanotube/alginate fabric for green electromagnetic interference shielding

Conductive polymer fabric with high-performance electromagnetic interference shielding effectiveness (EMI SE) acts as a shield between electromagnetic waves and humans. However, it is challenging to decrease the reflection loss of fabric with high SE. Nonmodified and nondestructive carbon nanotubes incorporated with ∼3 nm Fe3O4 nanoparticles (MCNTs) were dispersed in a sodium alginate solution to obtain a spinning solution, followed by wet spinning into MCNT/alginate composite fiber. The fiber is flexible and can be twisted and woven into a fabric with superior stress of 183 MPa, excellent EMI SE of 38.4 dB, low reflection coefficient of 0.165, and green shielding index (gs) of 5.06, which exceed the reported fabrics. The outstanding green EMI shielding performance is attributed to the outstanding electrical conductivity (221.9 S m−1) and moderate magnetic properties (saturation magnetization: 0.044 emu g−1). The as-prepared fabric retained 89.7% SE after being exposed to air for 8 months, indicating outstanding durability. Therefore, the fabric has great potential to be used as a green shielding cloth for enhanced protection.