Different properties and phenomena that polymer nanocomposites exhibit compared to the base polymers or conventional polymers (polymers with micron scale particles) are attributed to interfaces features. As a consequence, theories and models (such as Lewis' model, Tsagaropoulos' model and the multicore model proposed by Tanaka) have been proposed, primarily to interpret the physical, chemical and electrical structure of interfaces. Moreover, these models try to explain several different phenomena and properties that polymer nanocomposites exhibit based on the interfaces features. According to these models, the interface with thickness comparable to the diameter of the nanoparticle consists of multilayers. In this paper, a detailed review and analysis of these models and theories is presented. Differences and similarities of the models are also discussed.

No abstract

The influence of nanoparticles and homocharges on the propagation of electrical treeing in polymer insulation is examined for a needle-plane electrode arrangement. A simulation is carried out using a model based on Cellular Automata (CA). A DC voltage application on the needle electrode is assumed. Nanoparticles are introduced in the polymer matrix in the vicinity of the needle electrode, and simulations with different homocharge densities are performed. It is confirmed that the propagation of electrical trees is hindered by the presence of nanoparticles and homocharges. A larger quantity of homocharges forms a barrier to the injection of charge carriers in the nanocomposite sample. Electrical trees seem to go around and/or stop at nanoparticles and thus, their propagation becomes more difficult. In other words, the proposed simulations show that electrical trees follow a tortuous path, avoiding the nanoparticles.

Electrical Treeing Propagation in Nanocomposites and the Role of Nanofillers: Simulationwith the Aid of Cellular AutomataIn this paper the propagation of electrical treeing in nanodielectrics using the DIMET (Dielectric Inhomogeneity Model for Electrical Treeing) is studied. The DIMET is a model which simulates the growth of electrical treeing based on theory of Cellular Automata. Epoxy/glass nanocomposites are used as samples between a needle-plane electrode arrangement. The diameter of nanofillers is 100 nm. The electric treeing, which starts from the needle electrode, is examined. The treeing growth seems to be stopped by the nanofillers. The latter act as elementary barriers to the treeing propagation.

No abstract

No abstract

Electrical tree propagation in a polymer nanocomposite is affected by the presence of nanoparticles. A 2D cellular automata (CA) model is presented for the simulation of electrical tree propagation in polymer nanocomposites. The effect of the nanoparticles size, the nanoparticles loading and the appearance of microvoids on electrical tree propagation in titania ( TiO2 )/epoxy nanocomposites under the application of DC voltage is examined with the aid of the CA model. It has been observed that the tree length is affected by nanoparticles size and nanoparticles loading. A resistance in electrical tree propagation has been noticed, as nanoparticles size decreases or as nanoparticles loading increases. The presence of microvoids in the polymer nanocomposite is another factor that has been examined. The propagation of electrical trees that initiate from microvoids in the polymer nanocomposite has also been simulated by the use of the CA model.

No abstract