Carbon dispersion and morphology in carbon-mineral adsorbents

Carbon-mineral composite adsorbents prepared by deposition of carbon on var ious mineral supports have been studied extensively by a new textural appro ach. The evidence of significant influence of both organization of initial mineral support porous space and mobility of carbon precursors over the sur face of mineral support on carbon localization has been obtained. Restricte d 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 equiacces sible. Unrestricted mobility over the smooth surface of the mineral support without narrow mesopores leads to the similar resulting carbon distributio n. However, unrestricted mobility of carbon precursors in densely packed po rous materials seems to be the reason for carbon pulling and deposition in narrow mesopores. These peculiarities of carbon deposition influence the ca rbon/mineral (hydrophobic/hydrophilic) composition of the composite surface . Trapping of carbon in narrow mesopores leads to a decrease and, in contra st, homogeneous dispersion of carbon over the whole support surface leads t o an increase in the part of the composite surface, which can be appropriat ed to carbon. (C) 2000 Academic Press.