Fe3O4-loaded carbon nanotubes to enhance electromagnetic shielding of PAM/L hydrogels†

Abstract

Carbon nanotubes (CNTs) are common fillers, but their nanoscale radial size still offers great potential for processability. In this study, the mechanical strength and electrical conductivity of hydrogels were significantly improved by modulating the introduction strategies of CNTs and Fe₃O₄@CNTs, followed by synergistic interaction with Linum fiber (L). The results showed that the maximum compressive strength of the prepared hydrogel PAM/L/4-CNTs reached 17.82 kPa, and the electrical conductivity of PAM/L/6-CNTs reached 2.91 S m⁻¹. In addition, the interfacial polarisation effect enhanced the electromagnetic shielding (EMI) performance, with an average shielding effectiveness (SET) of 43.29 dB for PAM/L/6-CNTs, while the SET of Fe₃O₄@CNTs reached 41.52 dB at 4 wt%. All samples exhibited an absorption mechanism for electromagnetic shielding.