Facile preparation, characterization, and highly effective microwave absorption performance of CNTs/Fe₃O₄/PANI nanocomposites

A facile method has been developed to synthesize light-weight CNTs/Fe ₃O₄/PANI nanocomposites. The formation route was proposed as the coprecipitation of Fe²⁺ and Fe³⁺ and an additional process of in situ polymerization of aniline monomer. The structure and morphology of CNTs/Fe₃O₄/PANI were characterized by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FTIR) spectroscopy. The TEM investigation shows that the CNTs/Fe₃O₄/PANI nanocomposites exhibit less intertwined structure and that many more Fe₃O₄ particles are attached homogeneously on the surface of CNTs, indicating that PANI can indeed help CNTs to disperse in isolated form. The wave-absorbing properties were investigated in a frequency of 2-18 GHz. The results show that the CNTs/Fe₃O₄/PANI nanocomposites exhibit a super absorbing behavior and possess a maximum reflection loss of -48 dB at 12.9 GHz, and the bandwidth below -20 dB is more than 5 GHz. More importantly, the absorption peak frequency ranges of the CNTs/Fe₃O₄/PANI composites can be tuned easily by changing the wax weight ratio and thickness of CNTs/Fe ₃O₄/PANI paraffin wax matrix.