8th Liquid Matter Conference September 6-10, 2011 Wien, Austria ...

P2.44Tue 611:23-14:00The electric properties of ionic solutions at themembrane interface: a molecular dynamics studyGianluca Lattanzi, 1 Mauro Lorenzo Mugnai, 2 Giovanni Ciccotti, 1 and Ron Elber 21 University College Dublin, School of Physics, Engineering and Materials Science CenterDublin 4, Dublin, Ireland2 University of Texas at Austin, Austin, TX, Ud States of AmThe interaction of ions, small peptides and drug molecules with biological membranes is of fundamentalimportance in molecular medicine. Significant effects are associated with the region nearthe surface of a liquid phase and an understanding of these is an important part of solution chemistry:some reactions only take place at an interface, as is the case for membranes. The structuraldescription of these systems at a molecular level can be used to control reactions at the interfaces.Molecular dynamics simulations have been extensively used to study the distribution of solvatedions in the proximity of conducting planes or in presence of biological membranes mainly in casesthat involved specific protein pores. We performed a systematic molecular dynamics study of ionicsolutions with different (1M, 0. 25M, 0. 1M) concentrations of physiologic ions in presence ofa model biologic membrane and a graphite layer of comparable size. Our study characterizes thedistribution of the ions at the interfaces subject to constant electric fields of different magnitude.The results are compared with previous models and known results in electrochemistry for the caseof conducting planes (the electrical double layer).44