What are the Physical & Chemical Properties of Carbon Black?
Carbon black is not soot or black carbon
Soot and black carbon, which are the two most common, generic terms applied to various unwanted carbonaceous by-products resulting from the incomplete combustion of carbon-containing materials, such as oil, fuel oils or gasoline, coal, paper, rubber, plastics and waste material. Soot and black carbon also contain large quantities of dichloromethane- and toluene extractable materials, and can exhibit an ash content of 50% or more.
Carbon black is chemically and physically distinct from soot and black carbon, with most types containing greater than 97% elemental carbon arranged as aciniform (grape-like cluster) particulate. On the contrary, typically less than 60% of the total particle mass of soot or black carbon is composed of carbon, depending on the source and characteristics of the particles (shape, size, and heterogeneity). In the case of commercial carbon blacks, organic contaminants such as polycyclic aromatic hydrocarbons (PAHs) can only be extracted under very rigorous laboratory analytical procedures (soxhlet extraction using organic solvents and high temperatures). These extracts, though they may be similar to those derived from soot, are unique, however, because carbon black extracts exist only in extremely small quantities. Water and body fluids are ineffective in removing PAHs from the surface of carbon black and, therefore, they are not considered to be biologically available. Two other commercial carbonaceous products often confused with carbon black are activated carbon and bone black. Each is produced by processes different from commercial carbon black and possesses unique physical and chemical properties.
Is carbon black a nanoparticle?
While primary particle (near spherical building blocks of carbon black) diameters are generally in the 10-300 nanometer range, carbon black products as placed into commerce (the final product) are agglomerates, which are much larger in size (100 - 1000 nanometers in diameter). These agglomerates do not break down into smaller components (e.g., aggregates) because of the effect of van der Waals forces unless adequate force is applied (i.e., shear force). Thus, as placed on the market, carbon black products are not nanoparticles.
For more information, please refer to the Resources from ICBA.