Journal Articles

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https://hdl.handle.net/20.500.14170/294

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Browsing Journal Articles by Subject "Activation energy"
  • Publication
    Nonisothermal kinetic degradation of Hybrid CNT/Alumina Epoxy Nanocomposites
    ( 2021)
    Muhammad Helmi Abdul Kudus
    ;
    Muhammad Razlan Zakaria
    ;
    Mohd Firdaus Omar
    ;
    Muhammad Bisyrul Hafi Othman
    ;
    Hazizan Md. Akil
    ;
    Marcin Nabiałek
    ;
    Bartłomiej Jeż
    ;
    Mohd. Mustafa Al Bakri Abdullah
    Due to the synergistic effect that occurs between CNTs and alumina, CNT/alumina hybrid-filled epoxy nanocomposites show significant enhancements in tensile properties, flexural properties, and thermal conductivity. This study is an extension of previously reported investigations into CNT/alumina epoxy nanocomposites. A series of epoxy composites with different CNT/alumina loadings were investigated with regard to their thermal-degradation kinetics and lifetime prediction. The thermal-degradation parameters were acquired via thermogravimetric analysis (TGA) in a nitrogen atmosphere. The degradation activation energy was determined using the Flynn–Wall–Ozawa (F-W-O) method for the chosen apparent activation energy. The Ea showed significant differences at α > 0.6, which indicate the role played by the CNT/alumina hybrid filler loading in the degradation behavior. From the calculations, the lifetime prediction at 5% mass loss decreased with an increase in the temperature service of nitrogen. The increase in the CNT/alumina hybrid loading revealed its contribution towards thermal degradation and stability. On average, a higher Ea was attributed to greater loadings of the CNT/alumina hybrid in the composites.
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  • Publication
    The effect of NH₄Br composition on electrical behaviour of 2-Hydroxyethyl cellulose solid biopolymer electrolytes
    (Semarak Ilmu Publishing, 2025-02)
    Nurul Faeqah Mazalan
    ;
    Mohd Ibnu Haikal Ahmad Sohaimy
    ;
    Azwani Sofia Ahmad Khiar
    ;
    Wan Mohd Khairul Wan Mohamed Zin
    ;
    Md Uwaisulqarni Osman
    ;
    Mohammad Fakhratul Ridwan Zulkifli
    ;
    Rafizah Rahamathullah
    ;
    Muthiah Muthuvinayagam
    ;
    Mohd Ikmar Nizam Mohamad Isa
    In this study, solid biopolymer electrolytes (SBEs) were developed as an alternative to liquid electrolytes for battery applications. 2-hydroxyethyl cellulose (2HEC) served as the polymer host in the preparation of SBE films, incorporating varying amounts of ammonium bromide (NH4Br). The films were then analysed using electrical impedance spectroscopy (EIS) to investigate its electrical properties. The system containing 20 wt.% of NH₄Br achieved the highest conductivity at 3.9510-5 Scm-1 at ambient temperature of 303 K. The 2HEC-NH₄Br SBE film system was subjected to temperature variations between 303 K – 373 K in increments of 10 °C, revealing an increase in conductivity with rising temperature. This observation suggests that the SBE system adheres to the Arrhenius law, enabling the determination of the activation energy (Ea) through temperature dependence plotting. The Ea for the most conductive system reflects the lowest energy, indicating minimal energy required for the excitation process within the polymer chain. This Ea value offers a deeper insight into the transport parameters, including the number of mobile ions, ions mobility and diffusion coefficient, as determined through the Rice and Roth method.