computational materials chemistry



We use mathematical modeling and computer simulations to understand the behavior of existing materials and to design new materials for solar energy capture, sensing, optics and catalysis. In particular, we study the structural and dynamic properties of complex fluids and the beautiful structures that appear spontaneously in these systems through the self -assembly of molecular and colloidal components. Projects other than those listed here are possible so don’t hesitate to visit us and have a chat if any of this sounds interesting to you.

 


Project 1

Assembly of nanorods at interfaces for solar energy applications
Among the barriers to making cheaper solar cells is the high cost of the single crystalline silicon and vapor deposition methods commonly used today. One possible solution is to print solar cells using an ink of semiconducting nanoparticles. In this project you will study how interfaces (fluid-fluid and fluid-solid) can be used to favour the self-assembly of nanorods into structures that appear optimal for light capture and charge transport. This will yield design rules that can be used by experimental collaborators to make desired assemblies in the laboratory for testing in solar cells (see Nano Letters 2010, 10, 195-201).

 


Project 2

Porous nanoparticle superlattices for catalysis and sensing (with Dr Toby Hudson)

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 particles with directional interactions are attractive candidates for making a new family of porous superlattices, with potential applications in catalysis, sensing, and optics. You will explore the range of assemblies that can be made, using Monte Carlo simulations and by extending a structural search algorithm. Interesting structures may be synthesized by experimental collaborators in Japan or the USA (see Nature Materials, 2012, 11, 181-137).

 


Project 3

Crystal growth of metal alloys (with Prof Peter Harrowell)

Crystallization is not only a remarkable process of self-assembly but it is also surprisingly persistent, occurring even in mixtures where the ordering involves composition as well as structure. In this project you will carry out computer simulations of crystal growth in models of some technologically important alloys to understand how the ratio of atomic sizes and the attraction between different species controls the rate of crystal growth.

 


Project 4

Response of glassy alloys to shear

Metal alloys that lack crystalline order have generated broad interest due to their unique physical, chemical and mechanical properties. For example, their atomic smoothness, high corrosion resistance and extremely high strength and elasticity give them potential as micromechanical gears, ship components and sports equipment. Unfortunately, they tend to also be brittle, which is a serious problem for many of these applications. In this project you will study how these materials respond to shear and how variations in their chemical structure can result in brittleness in some cases and ductile response in others (see Nature Physics, 2008, 4, 711-715).

 


Project 5

Using molecular hairs to dynamically tune colloidal interactions

In order for colloidal particles to assemble into ordered structures over large length-scales, it is essential that the interactions between them are properly tuned in terms of specificity and strength. Otherwise disordered aggregates will form, or no assembly will occur. Inorganic nanoparticles are typically covered with surfactant-like ligands, which are assumed to simply act as a repulsive buffer between the crystalline cores of the particles. However, recent results suggest that this is too simplistic a picture, especially for particles that have extended facets in at least one dimension. In this project, you will investigate how ordering of ligands on the surface of nanoparticles can be used to dramatically change their interaction by simply varying the temperature, and thus to turn assembly on and off in a reversible way.

 


For further information, please contact:

Dr Asaph Widmer-Cooper

Room 316

School of Chemistry

Eastern Avenue

University of Sydney NSW 2006

Phone: +61 2 9351 7392

Email asaph.widmer-cooper@sydney.edu.au