title: Competitive entry of sodium and potassium into nanoscale pores.
abstract: We have studied the competitive entry of potassium and sodium into carbon nanotubes using molecular dynamics simulations. Our results demonstrate how a combination of strong sodium hydration coupled with strong potassium-chlorine interaction leads to enhanced potassium selectivity at certain diameters. We detail the reasons behind this, and show how variation of nanotube diameter can cause a switch to sodium selectivity, or even cause a decrease in overall ion entry despite an increase in diameter. These results demonstrate the importance of considering inter-ion dependence in the theoretical study of pore selectivity and show that, with careful design, the practical separation of sodium and potassium is possible using diameter variation alone.
authors.affiliation: Department of Mechanical Engineering, Sogang University, 1 Shinsu-dong, Mapo-gu, Seoul, 121-742, Republic of Korea.
authors.forename: James J
authors.initials: JJ
authors.lastname: Cannon
authors.forename: Dai
authors.initials: D
authors.lastname: Tang
authors.forename: Nahmkeon
authors.initials: N
authors.lastname: Hur
authors.forename: Daejoong
authors.initials: D
authors.lastname: Kim
mesh_terms: D056004:Molecular Dynamics Simulation; D037742:Nanotubes, Carbon / Q000737:chemistry*; D010316:Particle Size; D011188:Potassium / Q000737:chemistry*; D012964:Sodium / Q000737:chemistry*
chemical_list: D037742:Nanotubes, Carbon; D012964:Sodium; D011188:Potassium