Experimental investigation of the effect of conducting fractal phases on the permittivity of composites

Study of Dielectric Properties of Polymer Systems Containing Nanosized Soot and Aluminum Particles

“…Satisfactory agreement was obtained between the calculated and experimental εˊ=εˊ (C) curves for the paraffin+Al system and for the paraffin+Fe system curves were obtained that had nothing to do with the experimental dependence of dielectric constant εˊ on the concentration of iron particles. The authors of the work [3] explain a similar situation with the possibility of formation of conducting chains inside a fractal in the composite under study. It is known that aluminum powder consisting of micron-sized particles has a surface layer of Al2O3, which is a good insulator with dielectric constant εˊ=10 and specific volume resistance ρv=1,5×10 9 Ohm×m.…”

“…Based on [3] the contact group method (equations (6) and (7)) was used to calculate the values of εˊ for paraffin+aluminum and paraffin+iron system. The main particle size of conductive iron impurities "r" is 6 × 10-6m; of aluminum "r" is 10-5m.…”

“…Using the method of contact groups according to the equations (6) and 7, based on the values of electrophysical parameters of conductive inclusions of Al particles of micron sizes given in [3] we calculated the dependence of the real part of dielectric constant of composite εˊˊ=εˊ(C) on the concentration of Al nanoparticles. They are presented in Fig.…”

“…It was shown that at a low content of Al and soot nanoparticles in the composite, significant changes are observed: extremes on the curves ԑ´=ԑ´(C), ρᵥ=ρᵥ(C), which do not fit into the Maxwell-Wagner polarization model. 3. Using a set of modern methods for studying macroscopic properties and electron microscopy to study the structure and morphology of supermolecular formations of composite, models were developed and possible physical mechanisms leading to extreme changes in ԑ´ and ρ´ᵥ in the region of low concentrations of nanoparticles were presented.…”

Analysis of electrical and dynamic mechanical response of conductive elastomeric composites subjected to cyclic deformations and temperature

“…The electrically conducting rubber composites are usually prepared by dispersing conducting fillers like carbon black, carbon fibre, carbon nanotube, graphene, coke, metal oxides (like alumina, mica) and non‐oxidizing metal powders (such as silver, nickel) in the rubber matrix . Among different types of conductive additives, carbon black is the most widely used for rubber matrix as it is less expensive, easily processed and also offers good reinforcement to the rubber matrix .…”