The authors have performed molecular dynamics simulations of polarizable solutes in water to investigate how solute polarizability affects solute-solute hydrophophic interactions. A degree of polarization similar to the one expected in biomolecules, corresponding to a dielectric response of =2-20, results in dramatic changes in the hydrophobic forces. They find that this degree of polarizability is enough to inhibit drying between hydrophobic solutes and to stabilize a reduced water density phase whose density is smaller than the bulk water density. The hydrophobic forces associated with such reduced density states are still very significant with values of the order of several tens of piconewtons. Their results suggest that polarizability plays an important role in determining the hydrophobic force acting between weakly polar surfaces.
Bibliographical noteFunding Information:
The authors would like to thank the EPSRC (F.B.) and The Royal Society (A.W.) for financial support. One of the authors (F.B.) would like to thank Professor Dietrich and Dr. Oettel for their hospitality at the Max Planck Institute for Metal Research-Stuttgart, where this manuscript was completed. Computer resources on HPCx was provided via the UK’s HPC Materials Chemistry Consortium (EPSRC Grant No. EP/D504872). The authors would like to acknowledge the Barcelona Supercomputer Center (Spain) for providing resources on the Mare Nostrum Supercomputer, and the London eScience Centre at Imperial College London (UK) for resources in the Viking Cluster.