Approved FOM programme
|Title||Proton mobility in confinement (PMC)|
|Executive organisational unit||AMOLF en BUW|
|Programme management||Prof.dr. H.J. Bakker|
|Duration||2010 - 2017|
|Cost estimate||M€ 2.4|
Main objective: elucidate the molecular-scale mechanism of proton conduction through aqueous media in confined geometries, specifically when confinement is limited to one‑dimension (aqueous systems at surfaces and interfaces), two dimensions (water in wires and channels) and three dimensions (nanopools/nanodroplets). The key question is to resolve how proton hydration in general, and the interruption of the hydrogen bonded network in confined spaces in particular, affect proton conduction.
Background, relevance and implementation
Proton transfer in aqueous media is an extremely widespread and important process in nature and technology. For bulk water and bulk ice strong indications have been found that protons are not transported by ordinary diffusion, but by special conduction mechanisms that strongly resemble the mechanism of transport of holes through a semi-conductor. While the fundamental principles of proton transport in a uniform bulk environment have recently been established, the most interesting and relevant aqueous proton transport processes that occur in complex, strongly confined environments, are not understood.
In many cases proton conduction takes place in confined water volumes. Examples are proton transfer along (biological) membranes, in small embedded water pools within proteins, through water channels like that of the channels of nafion membranes in hydrogen fuel cells, and through trans-membrane protein pores. Our understanding of the intricate process of proton conduction in these confined geometries is essential to comprehend - and ultimately control - the many important biological and technological systems that rely on this process. Despite the apparent fundamental and technological relevance of understanding proton conduction in confinement, the molecular-scale mechanism of proton conduction has remained a largely unexplored area of research. The reason for this lag in our knowledge is clearly not the lack of relevant questions, but the limited number of experimental and theoretical techniques that are sufficiently sensitive and specific to probe proton conductivity in confined spaces. Thanks to recent advances in experimental and theoretical techniques, this study has now become possible.
The final evaluation of this programme will consist of a self-evaluation initiated by the programme leader and is foreseen for 2017.
Please find a research highlight that was achieved in 2014 within this FOM programme here.