• Canada
• UKRI|EPSRC close
• 2015 close
• 2018 close

Material innovations focussing on delivery and sustainability are key as our global efforts intensify in the development of a secure and sustainable future energy landscape. Many infrastructure-related material challenges have emerged as a result of the need (i) to explore offshore marine environments for wind power generation, (ii) for deeper and more complex underground wellbore systems for new oil & gas explorations, (iii) for robust containment and shielding structures for new nuclear power plants and (iv) for larger dam structures for future hydropower generation. Our vision for this proposal is to build a world leading and long lasting partnership between academics in the UK and China, integrated with industrial partners and other world leading academic groups around the world, to collectively address some of those construction material challenges with a focus on sustainability. The commonality in the assembled group is our interest and expertise in exploring potentials for magnesia-bearing construction materials in solving some of those new challenges, by either providing completely new solutions or enhanced solutions to existing material systems. This is a unique area to China and the UK where there is significant complementary expertise in the different grades of and applications for magnesia. The project consortium from the University of Cambridge, University College London, Chongqing University and Nanjing Tech University has the required interdisciplinary mix of materials, structural and geotechnical engineers, with world leading unique expertise in magnesia-based construction materials. The intention is to share and advance our global understanding of the performance of those proposed materials, road map future research and commercial needs and identify the ideal applications in our future energy infrastructures where most performance impact and sustainability benefits can be achieved. The proposed focusses two main areas of research. The first is the technical advantages and benefits that magnesia can provide to existing cement systems. This includes (i) its use as an expansive additive for large mass concrete constructions e.g. dams and nuclear installations, (ii) its role in magnesium phosphate cements for the developing of low pH cements suitable for nuclear waste applications and (iii) its role in advancing the development of alkali activated cements by providing low shrinkage and corrosion resistance. The second is the delivery of sustainable MgO production processes that focus on the use of both mineral and reject brine resources. An integral part of this project will be the knowledge transfer activities and collaboration with industry and other relevant research centres around the world. An overarching aspect of the proposed research is the mapping out of the team's capabilities and the integration of expertise and personnel exchange to ensure maximum impact. This will ensure that the research is at the forefront of the global pursuit for a sustainable future energy infrastructure and will ensure that maximum impact is achieved. The consortium plans to act as a global hub to provide a national and international platform for facilitating dialogue and collaboration to enhance the global knowledge economy.

The global demand for smaller and more energy efficient devices has been sustained by a steady decrease in the scale on which silicon microelectronics can be manufactured, from 65nm processes in the mid 2000s to 14nm in the very latest Intel processors. To continue this trend beyond the mid 2020s devices with dimensions of just 1-2nm will be required, likely using alternatives to silicon. In this regime, the cross section of a wire might be no more than 2x2 or 3x3 atoms across, where the relevant materials physics is dominated by surface and confinement effects leading to dramatically different structural and electronic properties to the corresponding bulk material. Such wires can be formed by crystallisation of a molten salt within carbon nanotubes (CNTs) of "Buckytubes", leading to the smallest cross section nano crystals possible, sometimes referred to as Feynman crystals. Research into the fundamental materials physics of these CNT-encapsulated structures is still in its infancy, with UK experimentalists leading the way. Particularly exciting recent work by one of the applicants (Sloan) has demonstrated the possibility of these wires undergoing transitions between nano-crystalline structures with markedly different properties, in response to bending strain in the CNT. These "phase change" properties open the way for nanoscale electromechanical switches and non-volatile memory, as well as providing a playground for fundamental studies of phase changes at the smallest length scale possible in a material. Our aim with the current project, inspired by these results, is to develop a computational modelling capability to aid in interpretation of experiments, understand the origin of the phase change behaviour, and guide our experimental colleagues toward compounds with potentially advantageous properties. Counterintuitively, due to a reduction in symmetry, the computational expense of simulating nanowires can be more demanding when compared to bulk crystals. We will address the limitations of currently available modelling tools when applied to these systems. This will involve significant modifications to existing software and a rigorous study of the various approximations one might employ to increase the tractability of simulations. We will apply cutting-edge methods in structure prediction to these systems, a non-trivial exercise due to the possibility wires with non-crystalline (e.g. helical) symmetry, and connect directly to relevant experiments by computing spectra related to the encapsulated wire's electronic and vibrational properties. Finally, we will study the thermodynamics and kinetics of nano-crystalline phase change, developing an understanding of when and how rapidly structural changes are affected to assess the utility of this mechanism for device applications.