Modeling dielectric permittivity of polymer composites filled with transition metal dichalcogenide nanoparticles

A model is developed for the dielectric permittivity of polymer nanocomposites reinforced with transition metal dichalcogenide fillers at microwave frequencies. The model takes into account aggregation of nanoparticles into clusters (that involve both filler and matrix components) and the aspect ratio of aggregates. The governing equations involve four material parameters that are found by matching observations on the real and imaginary parts of the dielectric permittivity of polymers reinforced with MoS₂ and WS₂ micro- and nanospheres, MoS₂ nanosheets and nanoflowers, and composite heterostructures formed by MoS₂ and MoS₂-CoS₂ nanoparticles with graphene and reduced graphene oxide. Good agreement is demonstrated between results of simulation and the experimental data at frequencies in the S, X, and Ku bands of the electromagnetic spectrum. It is shown that composite heterostructures have superior dielectric properties compared with those of neat transition metal dichalcogenide nanoparticles.