DIFFUSION OF AGGREGATED FULLERENES IN SOLUTION

The diffusion of fullerenes in solution is studied taking into account the recently established formation of clusters containing numbers of aggregated fullerene molecules. Based on a droplet model of a cluster, the distribution function of fullerene clusters by size is obtained f or various concentrations of solution. It is shown that dissolved full erene is present mainly in the form of clusters at saturation conditio ns, but the contribution of clusters diminishes as the concentration d ecreases. Since the diffusion mobility of clusters is much less than t hat of molecules, it leads to the dependence of an effective diffusion coefficient on concentration, which is computed for the case of fulle rene C-60. The feasibility of the use of this dependence as a basis fo r a diffusion method of the separation and enrichment of the fullerene extract with a small addition of higher fullerenes is analyzed. Possi ble schemes for enrichment are discussed.