RETRACTED ARTICLE: Effect of carbon content on the electrical conductivity of carbon black-filled pmc with various matrices

Abstract

The electrical conductivity of carbon black-filled polymer matrix composites (PMC) with various matrices was studied as a function of carbon content to find the break point of the relationship between carbon content and conductivity. Conductivity jumps by as much as ten orders of magnitude at the break point. The critical carbon content corresponding to the break point varies depending on the matrix species and tends to increase with increase in the surface tension of the matrix. To explain the dependency of the critical carbon content on the matrix species, a simple equation was derived under some assumptions, the most important of which is that when the interfacial excess energy introduced by particles of carbon black into the matrix reaches a universal value (Δqc), the particles of carbon black begin to coagulate so as to avoid any further increase of the energy and to form networks which facilitate electrical conduction. The equation well explains the dependency through surface tension, as long as the difference of the surface tensions between the particles of carbon black and the matrix is not very small.