Research in maxwater
For many materials, and especially liquids, one can extrapolate the properties of the bulk from the properties of individual molecules. This extrapolation does not hold for water, as water exhibits strong collective effects, across many length and time scales. For a water molecule to reorient in the liquid, for instance, it has to break one of its hydrogen bonds with a neighboring water molecule. This is energetically so costly, that reorientation only occurs when the next hydrogen bonding partner is already available. However, that water molecule, in turn, must also remain sufficiently coordinated. As a result, the reorientation of one water molecule has effects beyond the first hydration shells, and is not simply diffusive, but occurs in discrete, femtosecond jumps, spaced by several picoseconds.
The hydrogen-bond network of water is responsible for many of the unique properties and anomalies of water. At the surface of ice and water, and at the interface with other molecules or materials, this network is interrupted, giving rise to yet other fascinating properties, such as the very high surface tension of water and the surface pre-melting, one bilayer at a time, of water molecules at the surface of ice, which is in part responsible for ice being slippery.
The recent advent of novel approaches, both theoretical and experimental, with the ability to characterize the structure and dynamics of water in complex systems at the molecular level, has prompted increased interest in investigating water at the molecular level across several disciplines. There are several research groups within the Max Planck Society that have the same aim, yet in different disciplines: to obtain a molecular-level understanding and description of water in complex environments and relate that understanding to macroscopic phenomena in aqueous systems. MaxWater provides a platform for joining these different disciplines, and creating synergies: to benefit from each other's expertise and techniques, so as to jointly tackle water's challenges.