Fabrication and investigation on the Fe₃O₄/thermally annealed graphene aerogel/epoxy electromagnetic interference shielding nanocomposites

Ethylenediamine functionalized Fe₃O₄ (NH₂-Fe₃O₄) nanoparticles and graphene oxide (GO) were compounded firstly, followed by the addition of L-ascorbic acid, to obtain the Fe₃O₄/thermally annealed graphene aerogel (Fe₃O₄/TAGA) by thermal annealing method. And the Fe₃O₄/TAGA/epoxy nanocomposites were then fabricated via template-casting method. When the mass ratio of GO to NH₂-Fe₃O₄ was 2:1 and the total mass fraction of Fe₃O₄/TAGA was 2.7 wt% (1.5/1.2 wt% Fe₃O₄/TAGA), the obtained Fe₃O₄/TAGA/epoxy nanocomposites presented the highest electromagnetic interference shielding effectiveness (EMI SE of 35 dB in the X-band), much higher than that of epoxy nanocomposites (10 dB) filled with the same Fe₃O₄/thermal annealing graphene oxide (Fe₃O₄/TAGO) loading. Meantime, the corresponding Fe₃O₄/TAGA/epoxy nanocomposites also presented the outstanding electrical conductivity of 27.5 S/m.