Vladislav Skorokhod

A Model of Electrical Conduction in Xerographic Toners as Polymer — Conductive Filler Particulate Composites

An equivalent circuit model of electrical conduction in toner particles with sub-monolayers of fine conductive additives on the surface was developed in this study. The equivalent circuit was constructed and represented mathematically by a linear system of nodal equations solved numerically by using Matlab software to calculate composite conductance as a function of the amount of conductive filler and filler-to-matrix size ratio. Additional capabilities of the present model include calculation of the statistical distribution of composite particle conductance, and the possibility to account for non-random configuration of filler particles.

An Equivalent Circuit Approach to Evaluating Conductivity of Polymer-Filler Composites

An equivalent circuit model of electrical conduction in polymer-filler particulate composites was developed in this study. The equivalent circuit was constructed for an individual composite particle with a sub-monolayer of conductive filler, where the filler particles play the role of circuit nodes, and inter-particle contacts are represented by resistors between the nodes. The mathematical representation of the equivalent circuit in the form of a linear system of equations for nodal potentials was solved numerically with Matlab software to calculate conductance of the composite as a function of the amount of conductive filler, filled fraction of the monolayer, filler-to-matrix size ratio and the degree of structuredness (non-randomness) of the filler material. Additionally, percolation concentrations and statistical distributions of composite conductance were calculated as functions of the filler-to-matrix size ratio.

Electrical Conduction in Iron Oxide Powder Coated with Polymethyl Methacrylate

Current-voltage and transient behaviours of iron oxide powder coated with polymethyl methacrylate (i.e., a model xerographic carrier) was studied by measuring current through powder piles sandwiched between two planar electrodes. A space charge limited process was identified as the major factor controlling transverse DC conduction in the coatings. Current-voltage hysteresis and the characteristic transient behaviour observed in the present structure indicate the presence of intrinsic longlifetime traps in polymethyl methacrylate, that may play a significant role in its triboelectric response.