computational materials chemistry
Predicting and designing the structures made by the self-assembly of nanoparticles into metamaterials is a key requirement for a new generation of advanced materials. Many fundamental questions are still open. The group’s research involves the computer simulation of complex materials, concentrating on issues of structure and dynamics. All of the projects involve computational experiments, but all can be done without previous experience of programming.
What is it about the shape of a particle that determines how well it packs?
Some particle shapes fill space better than others. In some applications this is good, and in others it is bad. Suppose you want to crystallize colloidal particles, but you want to generate a material with a high porosity. What shapes should you consider using? Using a program which searches for the densest crystalline configuration of a particular shape, you will perform computer experiments to discover the role of properties of the particle like symmetries, concavity, and aspect ratio.
What is the connection between random packings and crystalline packings?
Jammed random packings of particles play an important role in many industrial applications including the stability of mining stockpiles, the safety of pebble bed nuclear reactors, and the stability of amorphous thin films. But the theoretical understanding of these systems is still in its infancy – there is even still wide disagreement on how to define a random packing. Everyone is clear that they are not crystalline, but if you shake them just right, they can become more ordered. This project will investigate in what ways the random packings of a series of different particles are related to the ideal crystal structures of those same particles.
Living crystals (with Peter Harrowell)
“Precious opals” consist of ordered arrays of self-assembled silica spheres, sometimes in complex crystal structures analogous to chemical compounds. Most theories of opal formation assume that the spheres have finished growing before they aggregate into the superstructure. But how did they know what sizes to grow to, in order to form the complex structure that they haven’t yet been arranged into? In this project you will use simulations to study the development of crystal order as it evolves simultaneously with the distribution of particle sizes.
Porous nanoparticle superlattices (with Asaph Widmer-Cooper)
Nanoparticles can now be made with exquisite control of shape and are becoming increasingly important as building blocks for new high-tech materials. Mixtures of oppositely charged nanopolyhedra are attractive candidates for making a new family of porous superlattices, which have applications in catalysis, sensing, and optics. You will explore the range of superlattices that can be made, using Monte Carlo simulations and by extending a structural search algorithm. Interesting structures may be synthesized by collaborators at UC Berkeley.
For further information, please contact:
School of Chemistry
University of Sydney NSW 2006
Phone: +61 2 9036 7648