Facile hydrothermal synthesis and microwave absorption of halloysite/polypyrrole/Fe3O4

Abstract

In this study, the halloysite nanotubes/polypyrrole/Fe3O4 (HPF) nanocomposites were synthesized, and their microwave absorption properties were investigated. Fe3O4 nanoparticles were synthesized by the hydrothermal method. By adding halloysite nanotubes (HNTs) to Fe3O4 nanoparticles and using the polypyrrole (PPy) as a conductive polymer, the in-situ polymerization process on the surface of HNTs and Fe3O4 nanoparticles was performed. The characteristic peaks of PPy and HNTs in Fourier transform infrared (FTIR) spectra confirmed the well-synthetized nanocomposites processes. Field emission scanning electron microscopy (FE-SEM) images illustrated the morphology and uniform structure of nanocomposites. The HPF1 (1 mL PPy) and the HPF2 ((2 mL PPy) nanocomposites exhibit a saturated magnetization of 26.22 emu/g and 13.94 emu/g, respectively. The microwave adsorbents were prepared by adding 20 wt% of synthesized nanocomposites to the resin. The complex permittivity and permeability parameters of adsorbents were investigated in the range of 8–12 GHz. The minimum reflection loss (RL) was − 31.18 dB at 10.58 GHz for HPF1 nanocomposites corresponding for a thickness of 3 mm. The results indicate that the HNTs as an additive can improve the adsorption properties of PPy/Fe3O4 nanocomposites.