Sandwich-structured CNFs-CNTs/Ni:Co NWs composite film with excellent electromagnetic interference shielding performance

A sandwich-structured CNFs-CNTs/Ni:Co NWs composite film was prepared. • CNFs-CNTs/Ni:Co NWs film showed a high tensile strength of 45.9 MPa. • CNFs-CNTs/Ni:Co NWs film showed an EMI shielding effectiveness of 48.6 dB. • CNFs-CNTs/Ni:Co NWs film exhibited a thermal conductivity of 2.003 W·m⁻¹ ·K⁻¹ . With the increasingly serious electromagnetic pollution, the development of high-performance electromagnetic interference (EMI) shielding materials has become an urgent demand. Herein, a sandwich-structured cellulose nanofibrils (CNFs)-carbon nanotubes (CNTs)/nickel-cobalt alloy nanowires (Ni:Co NWs) composite film (CNFs-CNTs/Ni:Co NWs) was developed via a vacuum-filtration layer-by-layer assembly strategy. The core layer (CNFs-CNTs) endowed CNFs-CNTs/Ni:Co NWs with good flexibility, high strength, and electrical conductivity. The two outer layers (Ni:Co NWs) further improved the electrical conductivity of CNFs-CNTs/Ni:Co NWs and enabled the magnetic conductivity of CNFs-CNTs/Ni:Co NWs. This unique sandwich structure made the resulting CNFs-CNTs (40%)/Ni:Co NWs a high EMI shielding effectiveness (EMI SE) of 48.6 dB. The EMI absorption effectiveness (SE A ), EMI reflection effectiveness (SE R ), and green shielding index of CNFs-CNTs (40%)/Ni:Co NWs were 34.1 dB, 15.2 dB, and 2.3, respectively. The CNFs-CNTs (40%)/Ni:Co NWs also showed high strength (45.9 MPa) and good bending capability. Moreover, such CNFs-CNTs (40%)/Ni:Co NWs exhibited excellently thermal conductivity (2.003 W·m⁻¹·K⁻¹). This CNFs-CNTs (40%)/Ni:Co NWs represents a promising high-performance EMI shielding material. Download: Download high-res image (188KB) Download: Download full-size image