The interaction energies of the sodium ion, the chloride ion and the water molecules interacting with truncated carbon nanocones are modelled using the continuum approximation together with the Lennard-Jones potential as a model of selective filtration devices. There are five possible sizes of the carbon nanocones where we find that the strongest interaction energy arises from the nanocone with the cone angle of 19.2◦ because the total energy is originated merely by the van der Waals interaction which is a short-range interaction. The smaller width of the cones results in the greater interaction potential because the distance between each surface element of the cone and the ion is closer than those cones of the wider apex angles.

**Reference****
**P. Sarapat, N. Thamwattana, B. J. Cox and D. Baowan* (2020) Modelling carbon nanocones for selective filter, Journal of Mathematical Chemistry, Vol. 58, pp. 1650-1662.