STUDY OF SURFACE-ACTIVITY OF CARBON-BLACK BY INVERSE GAS-CHROMATOGRAPHY .1. EVOLUTION OF THE SURFACE-PROPERTIES OF CARBON-BLACKS UPON EXTRACTION

A semi-reinforced carbon black N772 was extracted with different organic solvents. The effect of this treatment on carbon black surface characteristics has been investigated by using inverse gas chromatography at infinite dilution and at finite concentration. It was found that the increase of the free energy of adsorption of the carbon black surface can be attributed to the appearance of high energy active sites which appear after extraction. Moreover, the surface properties of the extracted carbon blacks can be seen to be dependent of the nature of the solvent used and generally that the organic polar solvents are more effective than the aliphatic solvents.