Centre for Molecular Nanoscience, School of Chemistry, University of Leeds, Leeds LS2 9JT, United Kingdom.
J Phys Chem B. 2012 Sep 13;116(36):11205-16. doi: 10.1021/jp306126q. Epub 2012 Aug 29.
Molecular dynamics simulations based on an empirical force field have been carried out to investigate the properties of a zwitter-ionic phospholipid (POPC) bilayer in contact with a water solution of [bmim][Cl], [bmim][PF(6)] and [bmim][Tf(2)N] at concentration c = 0.5 M. The results reveal important and specific interactions of cations and anions with the bilayer. The bmim cation, in particular, shows a clear tendency to be incorporated tail-first into the bilayer. Cl remains in solution, PF(6) forms a thin layer on the lipid surface, and [bmim][Tf(2)N] precipitates out of the solution, giving rise to an ionic droplet deposited on the lipid surface. The simulation results provide a microscopic basis to interpret the available experimental observations.
