The trans-membrane mobilities of ions in a synthetic molecular channel under the influence of applied electric fields

Abstract

Molecular dynamics (MD) have been conducted on a proposed crown-ether-based artificial ion channel in a phospholipid bilayer membrane between two layers of aqueous sodium chloride solutions. Having estimated the strengths of electric fields that would result in the migration of monovalent ions in such a molecular system, MD is conducted in fields of varying strengths in which the progress of the transport of the ions is monitored through their mean displacements and described with the aid of atom-pair radial distribution functions. It is found that the Na⁺ ions are transported more easily than Cl⁻, and that the presence of water molecules in the channel facilitates ion-transport by cushioning the coulombic traps at the channel oxygen atoms.