Effective pair potentials for hollow nanoparticles such as those made from
carbon (fullerenes) or metal dichalcogenides (inorganic fullerenes) consist
of a hard core repulsion and a deep, but short-ranged, van der Waals attra
ction. We investigate them for single-walled and multiwalled nanoparticles
and show that in both cases, in the limit of large radii the interaction ra
nge scales inversely with the radius R, while the well depth scales linearl
y with R. We predict the values of the radius R and the wall thickness h at
which the gas-liquid coexistence disappears from the phase diagram. We als
o discuss unusual material properties of the solid, which include a large h
eat of sublimation and a small surface energy.