Molecular origins of physical properties in liquids

In liquids, the ability of neighboring molecules to rearrange and jostle past each other is directly related to viscosity, the property which describes the propensity to flow. The presence of hydrogen bonds complicates the molecular scale picture of viscosity because hydrogen bonds are attractive, directional interactions which, in some cases, results in transient network structures. We use experimental and computational methods to investigate the hypothesis that the timescale of hydrogen bond network reorganization is the dominant dynamical timescale associated with viscosity. Evidence of this will inform our understanding of viscosity in these important liquids and in other low entropy systems.

Perticaroli et al Phys. Chem. Chem Phys. 2017

Understanding the structure of biological membranes

The lipid raft hypothesis tells us that the lipids in the cell membrane are laterally organized to provide the resident membrane proteins an appropriate physical environment. The physical principles and biological mechanisms that control the size and composition of these lateral structure are the subject of substantial debate.  We seek to leverage new methods  to study the cell membrane at the molecular scale and to understand the many unexpected ways that it organizes itself.

Nickels et al. PLoS Bio. 2017, Nickels et al. J. Phys. Chem. Lett. 2017, Nickels et al. JACS. 2015.

Hydration water: water molecules at the interface

The structurally and dynamically perturbed hydration shells that surround proteins and biomolecules have a substantial influence upon their function and stability. This makes the extent and degree of water perturbation of practical interest for general biological/biophsyical study and for industrial formulations.  We use direct physical measurements, like inelastic neutron scattering, in combination with molecular dynamics simulations to study the structure and motions of water at the molecular scale to learn about these changes in their molecular properties.

Perticaroli et al. JACS, 2017. Nickels et al. Biomacromolecules 2016, Ishai et al. J. Phys. Chem. B. 2013. Nickels et al. Biophys. J. 2012.