Lightweight sandwich fiber-welded foam-like nonwoven fabrics/graphene composites for electromagnetic shielding

Highlights: • Nonwoven fabrics with sandwich and welding-network microstructure was first designed and manufactured. • Exceptional shielding effectiveness (23103.4 dB cm² g⁻¹) and mechanically robust with tensile MPa of 349 was achieved. • Multiple reflection effect should not be neglected in the ultrathin material. -- Abstract: With the remarkable increment speed of consumer electronics, shielding materials qualified for favourable minimal thickness, mechanical behaviors and efficient conduction path are imperiously demanded. To manufacture desired shielding materials qualified for favourable mechanical behaviors and efficient conduction path, we designed a foam-like nonwoven multiscale composite with welding-network, sandwich and random orientation combined architectures for the first time. A 0.5-mm-thick epoxy composite exhibits an outstanding shielding effectiveness of 65 dB, and the specific electromagnetic interference shielding effectiveness reaches to ∼23103.4 dB cm² g⁻¹, which surpassed that in reported literature. The continuous backbone with sandwich microstructure enables the epoxy composites to be mechanically robust with the tensile MPa of 349. The exceptional mechanical performance exhibited an alternative approach to exploit potentials of carbon fiber-based nonwoven fabrics for developing advanced multifunctional materials.