Molecular Dynamics of the transport of ions

Abstract

Molecular dynamics investigations of ions in certain non-bulk media predict that they are capable of significantly greater mobilities than in the liquid state. The entries of Li+, Na+, and K+ ions into a proposed synthetic channel are simulated across a bilayer membrane between two bulk aqueous salt solutions. The behaviours of the ions are investigated in the presence, and in the absence of an electric field applied along the channel axis. The ion channel described consists of twelve 15-crown-ether-5 rings bonded in a stacked conformation. The dynamics of ions as they encounter this channel is investigated in cases when several channels are embedded as a lattice into a bilayer membrane and also when a single channel floats freely in an aqueous electrolyte solution. The frictional forces opposing the ion trajectories are calculated (~10 nN) and found to be independent of velocity.