A six-fold difference in structure results in a six-order difference in conductivity: silica shell nanoarchitectonics on carbon black particles

Carbon black (Ketchen Black with a particle size of several tens of nm) was coated with silica with a varied thickness of 2 and 12 nm. Carbon/silica core–shell particles were grafted with the γ-methacryloxypropylsilyl group to be homogeneously dispersed into a poly(methyl methacrylate) film. The electrical conductivity of the poly(methyl methacrylate) films containing carbon/silica particles was successfully controlled by the thickness of the silica layer; silica coating with 2 nm thickness gave a conducting film, while that with 12 nm thickness gave a less conducting film with a remarkable difference on the order of 10⁶ (in volume conductivity).