Now showing 1 - 4 of 4
  • Publication
    Correlation between crystal structure and thermal reaction of TiO₂ - Graphene Oxide
    TiO₂ - Graphene oxide (GO) (GO = 0-1.0wt %) powders were synthesised using sol-gel method and annealed at 500°C. The samples were then characterised using X-ray diffraction (XRD). The additional of GO gave significant influence on the crystal structure of TiO₂. The lattice parameter of TiO₂ were increased with decreasing GO concentration. The unit cell volume of TiO₂-GO annealed in N2 decreased with the oxygen occupancy. In contrary, the TiO₂-GO annealed in O₂ has an increase in O₂ occupancies in the lattice that was nearly proportional to its unit cell volume. A continuous weight loss was recorded by TGA at a temperature range of T= 30 - 1000°C that were associated with H2O, C-H and C-O species. It is concluded that the Ti-O-C and Ti-C bonds were formed for samples annealed in O₂ and N₂ respectively. The weight loss of TiO₂-GO annealed in O₂ is lesser than that annealed in N2 for same concentration additional GO into TiO₂.
  • Publication
    Prediction of maximum spreading time of water droplet during impact onto hot surface beyond the Leidenfrost temperature
    ( 2021-12-01) ; ;
    Rahim Y.A.
    ;
    ; ;
    Ismail K.A.
    ;
    Ani M.H.
    When a water droplet impacts on a heated surface in the film boiling regime, it will spread, recede, and finally bounce off from the heated surface. These unique liquid-solid interactions only occur at high surface temperatures. Our main objective in this research is to measure the maximum spreading and residence time of the droplet and the findings were compared to theory. We focused our study in the film boiling regime. Brass material was selected as the test surface and was polished until it became a mirror polished surface. The temperature range for this experimental work was between 100 °C up to 420 °C. Degassed and distilled water was used as the test liquid. The high speed video camera recorded the images at the rate of 10,000 frames per second (fps). As a result, it was found that the experimental value of maximum spreading and residence time agreed closely with the theoretical calculation. A new empirical formula that can be used to predict the maximum spreading time in the film boiling regime is also proposed.
      2
  • Publication
    Correlation between crystal structure and thermal reaction of TiO₂ - Graphene Oxide
    TiO₂ - Graphene oxide (GO) (GO = 0-1.0wt %) powders were synthesised using sol-gel method and annealed at 500°C. The samples were then characterised using X-ray diffraction (XRD). The additional of GO gave significant influence on the crystal structure of TiO₂. The lattice parameter of TiO₂ were increased with decreasing GO concentration. The unit cell volume of TiO₂-GO annealed in N2 decreased with the oxygen occupancy. In contrary, the TiO₂-GO annealed in O₂ has an increase in O₂ occupancies in the lattice that was nearly proportional to its unit cell volume. A continuous weight loss was recorded by TGA at a temperature range of T= 30 - 1000°C that were associated with H2O, C-H and C-O species. It is concluded that the Ti-O-C and Ti-C bonds were formed for samples annealed in O₂ and N2 respectively. The weight loss of TiO₂-GO annealed in O₂ is lesser than that annealed in N2 for same concentration additional GO into TiO₂.
      1  8
  • Publication
    Review on performance of lithium titanate and its impurities dopant as a lithium-ion battery anode
    Li-ion batteries are the main source of energy for electronic devices such as cameras, calculators, mobile phones, laptops, and electric vehicles. Among the materials being considered, lithium titanate (𝐿𝑖4𝑇𝑖5𝑂12) has become a promising anode material due to its high stability and safety, as well as enabling high operability without sacrificing lifetime. However, in order to further improve performance and customise properties for specific applications, impurity dopants have been investigated as a means of modifying 𝐿𝑖4𝑇𝑖5𝑂12 performance. This paper examines 𝐿𝑖4𝑇𝑖5𝑂12 and its impurities as anode materials. Starting with a basic understanding of the crystal structure and characteristics of 𝐿𝑖4𝑇𝑖5𝑂12, its properties and applications. Besides, this study explores the effects of different dopants on the 𝐿𝑖4𝑇𝑖5𝑂12 on battery parameters. Based on various research studies and recent developments, the review summarises the current knowledge about 𝐿𝑖4𝑇𝑖5𝑂12 and impurity dopants. Each dopant's different effects on the lattice structure highlight its importance for further development. As a result, it may lead to future research of 𝐿𝑖4𝑇𝑖5𝑂12 anodes for large-scale energy storage technology.
      21  3