Filler-Elastomer Interactions. Part VI. Characterization of Carbon Blacks by Inverse Gas Chromatography at Finite Concentration

Abstract

Abstract Carbon blacks ranging from N110 to N990 were characterized by means of inverse gas chromatography at finite concentration. The isotherms, net heat, and spreading pressures for benzene and cyclohexane adsorption suggest a general trend of increasing surface activity with increases in specific surface area. This is in good agreement with surface-energy measurements reported previously. The energy-distribution function of adsorption shows that while the concentrations of low-energy sites are comparable for most of the carbon blacks, differences exist with regard to high-energy sites. These suggest that small-particle-size blacks possess a greater number of high-energy centers. The graphitization of carbon blacks results in a considerable reduction in their adsorption capacity and narrows the energy distribution of their surfaces. One can therefore conclude that high-energy sites play an important role in the determination of the surface energies and reinforcing ability of carbon blacks.