Electrical conduction and polarisation phenomena in polymeric dielectrics at low fields

Abstract

A general description is given of the behavior of polymeric dielectrics in low fields, including polarisation and depolarisation, and transient and steady state conduction, in isothermal and non-isothermal conditions. An attempt is made to present a unified interpretation applicable to all of these phenomena.

Polyethylene/silica nanocomposites: absorption current and the interpretation of SCLC

“…A common issues associated with current measurements through highly insulating materials is a degree of variability in the absolute magnitude of the test data [22]. To address this, Figure 2 shows an example of a plot of repeated absorption current measurements for the case of the unfilled polyethylene; three different pristine samples were used, to eliminate any possible effects associated with measurement history.…”

“…The current flow caused by the action of an applied electric field on charge carriers within a dielectric material can broadly be categorized into three types [22]: the initial current that flows through the material is the capacitive charging current, which causes a dramatic rise at the very beginning of the voltage application. This is followed by a gradual decrease of current, known as the absorption current or the anomalous current.…”

“…On the addition of a nanofiller, charge transport mechanisms will become yet more complicated, since the inclusion of nanoparticles will introduce extensive interfacial surfaces between the nanofiller and the polymer. The presence of such interfaces may directly introduce additional nanofiller/polymer trapping sites and/or modify the surrounding polymer morphology, thereby affecting the local density of states within the system.The current flow caused by the action of an applied electric field on charge carriers within a dielectric material can broadly be categorized into three types [22]: the initial current that flows through the material is the capacitive charging current, which causes a dramatic rise at the very beginning of the voltage application. This is followed by a gradual decrease of current, known as the absorption current or the anomalous current.…”

Surface fluorinated epoxy resin for high voltage DC application

“…The poor reproducibility of test data is, however, a common issue with current measurements [135]. Resistivity or conductivity on the surface cannot be measured accurately, only approximated, because some degree of volume resistance or conductance is always involved in the measurement.…”

“…It is important to note that, while the absolute surface current values differ for each sample, these variations fall within experimental uncertainties. The poor reproducibility of test data is, however, a common issue with current measurements [135]. Due to the variations in each measurement, the average data over two samples were plotted in the graph for a more accurate representation of the data.…”