Recent Studies of the Fine Structure of Carbon Blacks

Abstract

The paracrystalline nature of the fine structure of carbon blacks was first shown in high resolution phase contrast micrographs by Hess and Ban. These authors described the continuous network of distorted graphite layers within the carbon particles. Measurements of the spacings between these layers has been the subject of our recent work.The results show that the interplanar spacings have a distribution of sizes in all carbon blacks; for example, the variation in interplanar spacings in furnace blacks ranged from approximately 345 pm (picometers) to 450 pm. In addition, the spacing distribution is independent of both the size of the carbon particles or the degree of interparticle fusion.Carbon blacks made by the Oil Furnace Process and the Channel Process have the same fine structure, and the distribution of their spacings follows a log-normal distribution pattern. The average spacing for these carbons is 386 ±6 pm. The value obtained by X-ray diffraction methods, approximately 355 pm, is lower because the data is restricted solely to parallel planes.