Preparation and properties of flexible nanocellulose fibers/Ag nanoparticles composite films with excellent electromagnetic shielding performance

Abstract

In this work, the nanocellulose fibers (CNF) and Ag nanoparticles (AgNPS) composite films with obvious hierarchical structure via vacuum filtration were prepared. The AgNPS were immobilized in CNF through interactions between the hydroxyl and carboxyl groups on the CNF surface and the carbonyl group on the PVP chain on the AgNPs surface. The variation in the law of shielding effectiveness of composite films and the performance under optimal conditions under different mass ratios of nanocellulose to nanosilver were analyzed. The results showed that the AgNPS with a diameter from 22.8 to 39.4 nm were attached to the CNF surface uniformly. The surface roughness of the composite films was as low as 8.404 μm. The cross-section of the composite films showed the layered “mortar/brick structure” when the ratio of CNF (M1):AgNO3 (M2) increased from 1:4 to 1:20. The conductive network with the increased of AgNPS was formed on the composite films surface. The conductivity and the contact angle were 1184.16 S/cm and 94°, respectively. The average electromagnetic shielding effectiveness of the composite films reached 80.7 dB in the frequency ranging from 0.03 to 3000 MHz, which showed great application prospects in the field of flexible electromagnetic shielding materials.