/ 27 May 2011

Computational modelling of materials: An emerging tool for value addition in South Africa

Computational Modelling Of Materials: An Emerging Tool For Value Addition In South Africa

Professor Phuti E. Ngoepe, SARChI Chair in Computational Modelling of Materials: Materials Modelling Centre, University of Limpopo

Over the years, the University of Limpopo has employed computational modelling, a third emerging scientific methodology, for predicting and optimising properties of materials. SARChI created space for extending high-performancecomputing to value addition of minerals and diversification of energy sources; challenges that are key to economic growth in South Africa.

High-energy density batteries are central to the development of electric vehicles, solar energy storage and electricity utility backups. Their enhanced performance, such as higher capacity, is now achieved with nanoparticle, nanorod, nanosheet and nanoporous structured electrodes.

One of the world-leading approaches of simulating such nanostructures for Lithium-ion and the emerging Lithium air batteries has been developed, particularly for Manganese and Titanium compounds. These enable prediction of related voltage profiles and produce microstructures that are amenable for determining distances electric vehicles can travel before needing recharging.

Efficient mineral processing methods, which address challenges of water, energy and environmental conservation in the mining sector are becoming imperative. Mineral surface properties by ab initio methods have been studied.

In order to initiate large-scale simulations, the research has derived and validated empirical potentials for mineral sulphides occurring in platinum ores and generated parameters for semi-empirical approaches. These have ushered in studies of surface properties of large systems with sufficient accuracy, including nanoparticles.

Lastly, phase stabilities of precious- and light metal alloys from a combination of energetics, elastic properties and phonon dispersions have been studied. The approach has provided valuable information for aerospace applications, shape memory devices and general powder metallurgy processing.

Research contributions have generated material for 30 publications and 80 presentations at local and international conferences, with nine keynote addresses. Fifteen Honours, nine MSc and PhD students have completed their research and 20 are currently being supervised. Four postdoctoral researchers have been associated with the Chair.

Five emerging researchers are currently participating in the main computational research themes at UL and other institutions. Some have received national awards e.g. Dr Regina Maphanga was the 2009 winner of the NSTF Research Awards for young black women researchers. The Chair has provided an excellent opportunity of participating in building good infrastructure at UL and the CHPC, which has made South Africa competitive.

Furthermore, there has been wide collaboration, especially with researchers from the United Kingdom and through membership of international consortia to develop simulation software that has enabled the research to move up the modelling time and length scales.

Professor Ngoepe was awarded the National Research Foundation President’s Award for the Transformation of the Science Cohort and bestowed an Order of Mapungubwe Silver (OMS) Award by the President of the Republic of South Africa, for excellent contributions in Natural Sciences in 2008.

This article originally appeared in the Mail & Guardian newspaper as an advertorial supplement