Browsing by Author "Wang, C"

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    Multifunctional rubber based composites for marine applications: A review
    (Engineers Australia, 2017-11-27) Fu, Y; Yeoh, GH; Wang, C; Peng, ZX
    Rubbers are widely used materials, and fillers play an important role in enhancing the electrical, thermal and mechanical properties of rubber based composites. In recent years, nano-fillers have attracted considerable attentions due to their ability to impart multifunctional properties to rubber matrixes. In spite of the various advancements of multifunctional rubber based composites in dry conditions such as for land-based uses, many developments are still required for wet conditions such as for marine applications. As ocean covers over 70% of Earth's surface, there are high demands for multifunctional rubber based composites in marine environments and the challenges are different to those in dry conditions. Three key challenges to be addressed are the acoustic characteristics (e.g. sound absorption), wettability in relation to fluid drag reduction and antifouling property. This paper firstly reviews the past and current advancements on synthesis and characterisation of rubber and its reinforced composites. Design and development of rubber based composites will be directed towards the availability of techniques and processes to manufacture the necessary multifunctional properties (compositions, structures and/or surfaces) and evaluating the performance in harsh marine environments. Each key challenge as aforementioned will be addressed individually through review of experimental and numerical approaches to thoroughly assess the multifunctional properties of rubber based composites with the specific focus on the state-of-the-art technologies for marine applications. Future directions are also proposed.© 2017 Engineers Australia
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    New electrode materials for lithium- and sodium-ion batteries
    (Society of Crystallographers in Australia and New Zealand, 2017-12-03) Xia, Q; Ling, CD; Wang, C; Avdeev, M
    As a result of increased energy demand, energy storage has become a growing global concern over the past decade. Electrochemical energy storage (EES) technologies based on batteries are beginning to show considerable promise as a result of many breakthroughs in the last few years due to their appealing features including high round-trip efficiency, flexible power, energy characteristics to meet different grid functions, long cycle life, and low maintenance [1, 2]. My project focuses on the discovery, characterisation and optimisation of electrode and solid electrolyte materials in both lithium-ion batteries and sodium-ion batteries, in which the investigation of nuclear materials and magnetic structures and the dynamics of Li/Na ion are key issues. In this presentation three techniques below that have been heavily utilised to theoretically and experimentally characterise new electrode materials will be systematically discussed. 1. Ab initio calculation—It is employed to identify and compare the energies of framework structures with hosting Li/Na from materials data mining, which give an improved understanding of how the experimentally determined structures arise and how they will evolve with mobile ion concentration under electrochemical cycling. Knowledge of the ground-state magnetic structure also permits the accurate calculation of redox potentials, in conjunction with electrochemical measurements. 2. Neutron scattering—It concerns new crystalline materials for light metal-ion batteries in several ways. Neutron diffraction reveals the location and occupancies of Li/Na sites in the crystal lattice and, hence, conduction pathways. In situ experiments explicitly reveal Li/Na ion mobility, as well as phase changes under operating conditions that undermine long-term stability. Inelastic and quasielastic neutron scattering probe the dynamics of the mobile ions and the supporting lattice. Besides, low temperature neutron diffraction reveals the spin-ordered ground states of the transition metal countercations, which are not only fundamentally fascinating due to their complex super-super-exchange pathways, but also characteristic of their electrochemical states in batteries. 3. In-situ TEM characterisation—It is performed to study how materials degrade on a larger scale over repeated cycling: nanocrystallisation, and changes in the roughness of the interfaces. The information of the materials failure collected by virtue of this technique will help to effectively design accurate ways to optimise the materials.
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    WOMBAT – high Intensity powder diffractometer at OPAL
    (Australian Institute of Nuclear Science and Engineering, 2016-11-29) Studer, AJ; Peterson, VK; Maynard-Casely, HE; Hester, JR; Wang, C
    Wombat is a high intensity neutron diffractometer located in the OPAL Neutron Guide Hall. It is primarily used as a high-speed powder diffractometer, but has also expanded into texture characterisation and single-crystal measurement, particularly diffuse scattering. The high performance comes from the combination of the best area detector ever constructed for neutron diffraction with the largest beam guide yet put into any research reactor and a correspondingly large crystal monochromator, all combine to provide an instrument which is unique in its capabilities within the Southern hemisphere. Wombat has been used to explore a broad range of materials, including: novel hydrogen-storage materials, negative-thermal-expansion materials, methane-ice clathrates, piezoelectrics, high performance battery anodes and cathodes, high strength alloys, multiferroics, superconductors and novel magnetic materials.