ABSTRACT
I. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 833
II. Polyhedrical Nanocapsules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 833
III. Rounded Concentric Structures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 840
IV. Formation Kinetics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 842
V. Purification and Biological Coverage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 844
VI. Nuclear Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 846
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 848
Carbon nanocapsules [1-3] are polyhedrical shell structures that comprise several closed con-
centric graphene layers and a kernel. They have dimensions of the order of 50 nm and can have
an interior gap between kernel and capsule. Filled nanocapsules were first identified in arc dis-
charge experiments at very high temperatures by the simultaneous evaporation of graphite electro-
des charged with rare earth elements. Several types of nanocapsules with different compounds
inside have been already synthesized [4]. The polyhedrical capsules with up to 40 shells have inter-
layer spacings greater than in graphite and have chemical inertness similar as graphite. Rounded
vertex or spherical capsules are formed when pairs of carbon atoms are eliminated from the
shells of polyhedrical nanocapsules or multiwall nanotubes [5], and in this case interlayer spacings
can be smaller than in graphite. Different synthetic routes and purification methods are being
explored to overcome low production yields [6].
