The computational materials chemistry group performs fundamental and applied research into self-assembly, complex systems and the structure and properties of material systems, using quantum chemical and molecular dynamics techniques.
Controlling Carbon Nanotube “Growth”
Carbon nanotubes have remarkable electronic and optical properties that are determined precisely by their atomic structure, or ‘chirality’. Our group has performed a number of pioneering studies into how carbon nanotubes nucleate and grow (see this movie, showing nucleation on an iron catalyst nanoparticle), and how structural defects are then removed, or “healed”, naturally during the growth process. Our simulations are currently targeting the fundamental origins of these defects, towards revealing how they can be minimised in experimental synthesis.
Group members: Dr Supriya Saha, Izaac Mitchell, Tilly Eveleens
Graphene Formation Mechanisms
Our group is actively studying how graphene forms during chemical vapour deposition synthesis. Graphene is an atomic-scale chicken wire made of a single layer of carbon atoms, with remarkable properties – it is simultaneously the lightest, strongest and stiffest material known, but still conducts electricity roughly a million times better than copper wires. Our group has shown how important experimental factors, such as temperature, catalyst structure and the presence of sub-surface carbon, control the graphene formation process on transition metals such as nickel and copper.
Group members: Dr Supriya Saha, Izaac Mitchell
Structure in Ionic Liquids, and Solid – Ionic Liquid Interfaces
Simple inorganic salts like NaCl (M.P. 801 °C) melt when the temperature is sufficiently high to weaken electrostatic forces that lock the ions into a crystal lattice. Ionic liquids are molten salts, distinguished by having melting points below 100 °C, and have exhibit excellent thermal and electrochemical stabilities, and vanishingly low vapour pressures. Researchers are attempting to exploit these properties by incorporating ionic liquids into applications to produce a performance advantage over conventional solvents. This goal is impeded by the complex way in which ionic liquid ions arrange themselves in space – their “nanostructure” – particularly in the presence of a solid surface. Our group is currently researching how ionic liquids are structured on solid surfaces, such as graphite and silicate minerals, towards understanding how this can be optimised for lubrication and electrochemical processes.
Group members: Ryan Stefanovic, Ben McLean, Simone Waite
High Temperature Combustion Reaction Mechanisms
A number of toxic compounds, such as dioxins and benzofurans arise from the combustion of chlorinated hydrocarbons and thiophenols present in commercial pesticides. The aim of our research is to establish the chemical pathways by which these toxic compounds are formed. In conjunction with experimental groups at the University of Newcastle, we have established a number of reaction mechanisms present during these combustion processes, using quantum chemical methods and non-equilibrium molecular dynamics simulations.
Group members: Nwakamma Ahubelem, Tajwar Dar