Experimental Studies to Understand Solvents and Solvation

Abstract
Solvents and solvation play a key role in many natural and industrial processes, ranging from the dissolution of simple molecules, through to protein folding and molecular recognition, and on to fundamental problems such as colloidal stability and the phase behaviour of confined fluids. In these systems the observed properties often arise from a subtle balance between short-range intermolecular interactions and longer-range cooperative effects, for example electric double-layer forces and entropically driven hydrophobicity. One of the main challenges in the materials characterisation of such systems is therefore to obtain a detailed understanding of the structure and dynamics over a very wide range of length- and time-scales. The aim of this project is to address this problem.
The student will combine small- and wide-angle neutron and X-ray diffraction, to provide a coherent picture of the structure of polar liquids in a range of environments and systems. Spectroscopic scattering methods will also be used to probe the molecular dynamics and longer-time diffusion. A key element of the project is the need to apply and develop the underlying data analysis and modelling protocols, to allow us to cross from the microscopic to mesoscopic regimes. This will involve a combination of ensemble-based molecular simulation methods and coarser grained model fitting. Experiments will be conducted at the ISIS Facility (Rutherford Appleton Laboratory, RAL) and other central neutron and X-ray scattering facilities. In addition, we will use a range of in-house equipment, including SAXS and calorimetry. Systems of particular interest include simple apolar solutes and hydrates, clay-water interfaces and intercalates, nanoparticle solvation and dissolution, and electron solvation and delocalisation. The project will include a placement at RAL.