My research employs specially tailored simulation techniques to investigate the structure, dynamics and thermodynamics of molecular, colloidal and biological systems. A key element in my approach is the use of coarse-grained models that provide insight into a problem by being as simple as possible while retaining the essential chemistry and physics
Colloids consist of nanometre scale particles of one phase dispersed in another. Everyday examples include milk (an emulsion of fat globules in water) and paint (a suspension of solid pigment particles in a liquid). The shapes of and interactions between colloidal particles can be finely controlled in the laboratory, and colloids can therefore be considered as "designer atoms." This level of control leads to the possibility of designing new materials with interesting and useful properties. Computer simulation, in conjunction with the theory of statistical mechanics, plays an important role in making the connection between the interactions of individual particles and their collective behaviour.
A major goal in this sort of study is to discover how to design particles that will self-assemble into target structures without detailed intervention. Nature provides many examples of efficient self-assembly such as the cooperative folding and assembly of proteins into highly organised complexes, and the assembly of the protein shells (capsids) that encapsulate the genetic material of viruses. Understanding these processes is of interest both for the fundamental science and for potential applications in technology and medicine.
A transient gel of dipolar particles. The particles are coloured according to which cluster they belong to and the red cluster spans the box or "percolates." The particles are only physically bonded and the chains can rearrange, but at low temperature, the network becomes long-lived and the motion of the constituent particles becomes restricted.