Reactive polymeric ligand mediated one-pot synthesis of hybrid magnetite nanospheres for enhanced electromagnetic absorption

The facile preparation of magnetite nanostructures with diverse electromagnetic (EM) loss pathways is highly essential for their practical application in EM absorption. In this work, we have synthesized a reactive polymer (polyarylene ether, PAE) containing multiple polar groups, which has been employed as structure-directing agent to enable one-pot fabrication of PAE@Fe 3 O 4 hybrid nanospheres. Systematic characterization demonstrated that the fine morphology, crystal structures, surface charge and magnetic properties of the obtained hybrid nanospheres were highly dependent on the loading content of polymer ligand. Furthermore, thanks to the metal-ligand bonding between Fe 3 O 4 and PAE, several electromagnetic loss pathways, including multiple polarization, improved impedance matching and intrinsic magnetic response, have been synergistically unified in the obtained PAE@Fe 3 O 4 hybrid nanospheres. Consequently, the optimized PAE@Fe 3 O 4 hybrid nanospheres exhibited a maximum reflection loss of −56.7 dB and effective absorption bandwidth of 3.9 GHz, which was respectively enhanced by 41% and 63% compared with pristine Fe 3 O 4 nanospheres. Basically, the current work opens a new way to fabricate high performance magnetite-based EM absorbers that can be easily dispersed in various polymer matrixes, which is of great interest for the development of flexible electromagnetic radiation controlling devices.