Proton conduction in aqueous systems
In view of the fact that proton transfer in bulk water involves the collective restructuring of many water molecules, it is to be expected that the rate and mechanism of proton conduction will be strongly dependent on the nearby presence of solutes and surfaces. We will study the effect of ions and hydrophobic molecular groups on the proton transfer. In many cases proton conduction takes place in extremely small water volumes. Examples are proton transfers in small embedded water pools within proteins or through water channels of trans-membrane peptides like ATP-ase and gramicidin, or through the channels of nafion membranes in hydrogen fuel cells. The confinement of water in small channels and volumes will have a profound effect on the rate and mechanism of proton transfer. We will study the influence of nanoconfinement on proton conduction for several systems including nafion membranes and protein channels.