The non-bonded interactions between carbon nanostructures are studied. In particular, we focus on various interactions which involve a fullerene molecule. Using the Lennard-Jones potential and the continuum approach, we provide the potential energy for fullerene-atom interactions and by assuming that this atom is a typical atom on the surface of other carbon nanostructures, we derive the total potential energy for two non-concentric fullerenes, nested fullerenes, or carbon onions, a fullerene inside a carbon nanotube and nanopeapods. A simple mathematical model is also presented for the oscillation of a fullerene inside a carbon nanotube. This oscillation produces a frequency in the gigahertz range, providing the potential for devices such as ultra-fast optical filters and ultra-sensitive nanoantennae. Further, issues involved self-assembled hybrid carbon nanostructures known as nanopeapods are studied. We consider three encapsulation mechanisms for a C60 fullerene entering a tube: (i) through the tube open end (head-on), (ii) around the edge of the tube open end and (iii) through a defect opening on the tube wall. Once C60 fullerenes are encapsulated inside a nanotube, the arrangement of C60 fullerene chains is investigated. In particular, we consider both zigzag and spiral patterns for the fullerene chains. http://www.maths.usyd.edu.au/u/AppliedSeminar/abstracts/2008/thamwattana.html