Particle Size Analysis of Carbon Black

Abstract A new technique is described for measuring the size distribution of submicrometer sized powders, such as carbon black. Powder is first dispersed as an aerosol and the particle size is subsequently measured with a differential mobility classifier and an aerosol concentration detector. The technique has been used to provide a size distribution for seven American Society for Testing and Materials (ASTM)/D1765 designated grades of carbon black (N110, N234, N299, N330, N650, N683, N762). In addition, four grades (N234, N330, N683, N762) are designated by ASTM D24 committee on carbon black as Standard Reference Blacks in the SRB‐3 series (C3, B3, D3, A3, respectively). The effectiveness of the dispersion technique is discussed and size distribution data is presented on the seven ASTM grades of carbon black. For the sake of comparison, the same carbon blacks have been sized with a completely different measurement technique. This technique measures the diffusion coefficient of a dilute particle suspension from which a mean hydrodynamic particle diameter is determined. Size distribution data using this technique is also presented.