Energy storage relies on highly concentrated electrolytes with finely tuned physical and electrochemical properties. However, many fundamental aspects of the chemical physics of concentrated electrolytes remain unclear or difficult to explain due to the complexity of ion correlations and excluded volume effects at high (charge) density. We carry out delicate high resolution measurements to determine the electrostatic screening properties and structural arrangement of ions and solvent, in particular at electrode-electrolyte interfaces.
Osmolytes and natural electrolytes
Natural cytosolic electrolytes consist of multiple ionic, zwitterionic, and molecular components. Through fine tuning of this electrolyte recipe, organisms maintain the necessary osmotic pressure at the same time as optimising intercellular processes. We are studying the way in which this complex molecular and ionic environment influences interactions between particles. The results are relevant in many directions, from design of lab-based biochemical experiments to the interpretation of the evolutionary chemistry of life.
The Surface Force Balance
We are an experimental research team, with special expertise in using a Surface Force Balance (SFB) to study fluids, interfaces, and surface forces. The interaction force is measured between two solid cylinders, atomically smooth and mounted in crossed orientation, as a function of their separation distance with ~ 0.1 nm resolution. Mirrors behind the solid substrates are used to create an interferometer for the precise distance and force measurement.
Molecular mechanisms of friction and energy dissipation
Friction is the resistance to relative motion caused by inter-particle forces. It occurs across all lengthscales, from the friction of individually mobile atoms and molecules (which causes ‘viscosity’), to shearing interfaces (such as in human knee joints), to massive collective effects in geological formations that manifest as earthquakes. We are interested in understanding the molecular origins of friction, and from this we are developing ways in which friction can be manipulated to control locomotion, sliding and energy dissipation.