The role of MnO2/polyaniline/Y-type barium hexaferrite (Al2Y, Mg2Y, and Ni2Y) nanoparticles in the improvement of the microwave absorption properties of polyester coatings

It is well accepted that the use of nanoparticles in microwave absorbents (MA) can enhance their flexibility and performance. In this work, Y-type barium hexaferrite (Al2Y, Mg2Y, and Ni2Y), MnO2, and polyaniline nanoparticles were successfully prepared by using methods of sol–gel auto combustion, chemical co-precipitation and interfacial polymerization, respectively. The prepared nanoparticles were then inserted within a matrix of polyester resin. The phase structure, particle size, morphology, and performance of the prepared absorbers were indicated by an X-ray diffractometer (XRD), a scanning electron microscope (SEM), and a vector network analyzer (VNA), respectively. The influence of four critical parameters on the performance of the absorbers was studied by the Taguchi method to achieve an optimal formulation. For this, parameters investigated include the type of metal in Y-type barium hexaferrite (Al, Mg, and Ni) and the weight ratios of hexaferrite, MnO2, and polyaniline to the total weight of the sample. The results displayed that the sample prepared under optimal conditions has good impedance matching, and minimum reflectance loss (RL) of −36 dB at 10.5 GHz (equal to 99.99% effective absorption) with the thickness of 1.9 mm. Therefore, the optimal nanocomposite based on polyester containing the filler nanoparticles of Al2Y barium hexaferrite/MnO2/polyaniline is an excellent candidate for microwave absorption.