Quantification of Buckminsterfullerene (C60) in non-graphitizing carbon and a microstructural comparison of graphitizing and non-graphitizing carbon via Small Angle Neutron Scattering

In this article we present the first experimental evidence confirming a global presence of Buckminsterfullerene (C60) in non-graphitizing polymeric carbon, along with its volume fraction calculations. Partially stacked carbon fragments featuring weak or strong curvatures constitute the structural units in non-graphitizing carbons. It has been proposed that a certain fraction of completely closed spherical fullerenes, such as C60, is also present in these materials. Strongly curved structures are not expected to exist in graphitizing carbons. We report on a Small Angle Neutron Scattering (SANS) investigation conducted at the Institut Laue-Langevin, Grenoble, France, that enables us to (i) quantify C60 in a non-graphitizing carbon, (ii) investigate the evolution patterns of graphitizing and non-graphitizing carbons, and (iii) perform a detailed SANS analysis of pure crystalline C60 in dry powder form. We also revisit the formation patterns of slightly larger structures (3–5 nm) such as graphitic crystallites and voids in both classes of polymeric carbon. These results provide a strong evidence in support of the fullerene-like microstructural models of non-graphitizing carbon, adding that the curved structural units are not just “fullerene-like”, but also spherical fullerenes, C60 in particular.