Carbon Dispersion and Morphology in Carbon-Mineral Adsorbents

Carbon-mineral composite adsorbents prepared by deposition of carbon on various mineral supports have been studied extensively by a new textural approach. The evidence of significant influence of both organization of initial mineral support porous space and mobility of carbon precursors over the surface of mineral support on carbon localization has been obtained. Restricted mobility of carbon precursors leads to homogeneous distribution of carbon clusters over the support surface despite the presence of narrow mesopores in the structure of the support if the entire support surface is equiaccessible. Unrestricted mobility over the smooth surface of the mineral support without narrow mesopores leads to the similar resulting carbon distribution. However, unrestricted mobility of carbon precursors in densely packed porous materials seems to be the reason for carbon pulling and deposition in narrow mesopores. These peculiarities of carbon deposition influence the carbon/mineral (hydrophobic/hydrophilic) composition of the composite surface. Trapping of carbon in narrow mesopores leads to a decrease and, in contrast, homogeneous dispersion of carbon over the whole support surface leads to an increase in the part of the composite surface, which can be appropriated to carbon. Copyright 2000 Academic Press.