CHEMICAL MODIFICATIONS AND SURFACE PROPERTIES OF CARBON BLACKS

摘要

Five carbon blacks, differing in origin or specific surface area, were submitted to a series of chemical treatments: moderate oxidation with potassium persulfate, severe air oxidation, halogenation with chlorine or bromine, and grafting of short (ethyl, butyl, pentyl) or long (lauroic) alkyl chains in order to modify their surface properties and to compare their reactivity in relation to their atomic structure. Various techniques such as elemental analysis, active surface-area determination and inverse gas chromatography were used to assess the consequences of the modifications. In particular, inverse gas chromatography at infinite dilution is shown to detect essentially the most active sites, and allows monitoring of the variation of surface properties upon chemical modification of the blacks.