Mapping the Electrical Conductivity of Poly(methyl methacrylate)/Carbon Black Composites Prior to and after Shear

In this letter, the electrical conductivity of disklike poly(methyl methacrylate)/carbon black composite samples was investigated prior to and after a shear process. Novel electrical conductivity maps of the samples as a function of the position were obtained. It was found that the electrical conductivity after angular averaging of the static (nonsheared) sample is, as expected, independent of the radius. However, for the sheared sample, the electrical conductivity is decreasing from the center to the outer rim of the sample. This is attributed to the interplay of destruction and buildup effects of the applied linear shear stress on the agglomerate network.