Hierarchical composite nanoparticles of multiwall carbon nanotube (MWCNT)-Fe3O4@Ag combining

electrical conductivity and magnetism were obtained from acyl-amine reaction between carboxylation of

Fe3O4@Ag (Fe3O4@Ag-COOH) nanoparticles and amino functionalized MWCNTs (MWCNTs-NH2). Finally,

the MWCNT-Fe3O4@Ag/epoxy nanocomposites were fabricated via blending-casting method. When the

mass ratio of MWCNTs-NH2 to Fe3O4@Ag-COOH was 9:1 (MF-10), the corresponding epoxy nanocomposites

presented an optimal electrical conductivity and electromagnetic interference (EMI)

shielding effectiveness (SE). Furthermore, the MF-10/epoxy nanocomposites with 15 wt% MF-10 presented

a satisfying EMI SE of 35 dB and high electrical conductivity of 0.280 S/cm, satisfactory thermal

conductivity (thermally conductive coefficient, l of 0.46 W/mK), outstanding Young''s modulus of

4.60 GPa & hardness value of 0.26 GPa and excellent thermal stability (THRI of 183.4
C). The introduction

of Fe3O4@Ag nanoparticles not only enhanced the interaction among MF-10, so as to promote the formation

of conductive networks, leading to higher l and EMI SE value, but also contributed to hysteresis

loss of electromagnetic waves, and offered more interfaces to reflect and reabsorb electromagnetic

waves, resulting in highly improved attenuation of electromagnetic waves.