Measurement of the second virial coefficient of C-60 in CS2 solution from small-angle neutron scattering

Small-angle neutron scattering (SANS) is used to measure the second virial coefficient (A(2)) of C-60 in CS2, which gives a value of 0.0098 cm(3) g(-2) mol. This unexpectedly high value of A(2), along with a measured radius of gyration of 3.91 Angstrom which is higher than the 3.48 Angstrom theory value supports the solvated fullerene model of a C-60 molecule associated with a single layer of 24 CS2 solvent molecules. This model is supported by published data from a review of other solution techniques. A discussion of the SANS methodology needed to model highly characterized systems such as fullerenes is given.