Now showing 1 - 5 of 5
  • Publication
    The Influence of Compounding Parameters on the Electrical Conductivity of LDPE/Cu Conductive Polymer Composites (CPCs)
    ( 2021-11-12)
    Farah Badrul
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    ; ; ;
    Nor Asiah Muhamad
    ;
    ;
    Nurul Afiqah Saad
    ;
    Syatirah Mohd Noor
    Low-linear density (LDPE) and copper (Cu) were used as main polymer matrix and conductive filler in order to produce electrically conductive polymer composites (CPC). The selection of the matrix and conductive filler were based on their due to its excellence properties, resistance to corrosion, low cost and electrically conductive. This research works is aimed to establish the effect of compounding parameter on the electrical conductivity of LDPE/Cu composites utilising the design of experiments (DOE). The CPCs was compounded using an internal mixer where all formulations were designed by statistical software. The scanning electron micrograph (SEM) revealed that the Cu conductive filler had a flake-like shape, and the electrical conductivity was found to be increased with increasing filler loading as measured using the four-point probe technique. The conductivity data obtained were then analysed by using the statistical software to establish the relationship between the compounding parameters and electrical conductivity where it was found based that the compounding parameters have had an effect on the conductivity of the CPC.
      1  27
  • Publication
    Physical characteristic and in-vitro bioactivity property of sintered glasses made via sol-gel and powder sintering process
    In this work, ternary system (SiO2-CaO-P2O5) biocompatible glass with different compositions (CaO/P2O5 ratio) were prepared by sol-gel method and sintering process. The physical characteristic and bioactive properties of each different sample composition were analyzed using XRF, particle sizer, N2 adsorption-desorption, FTIR, XRD, and FESEM-EDX. The sintered glass pellets were subjected to immersion studies in a simulated body fluid (SBF) solution for 14 days. All compositions of gel-glass particulates showed mesoporous-type structures and consisted of very high porosities with nano-pores in size. Different Ca/P ratios in gel-glass composition are affected by different porous characteristics. All compositions of sintered glass showed very good bioactive behavior by significant deposition of the carbonate apatite layer. Sintered glass with the Ca/P ratio = 2.33 showed very significant bioactive properties as it also comprised the highest pore volume and size. However, sintered glass with the lowest Ca/P ratio (Ca:P=1.50) showed a quite significant reduction in the bioactive property as it also consisted of the lowest pore volume and pore sizes. Hence, the in-vitro bioactivity property of sintered glass is significantly influenced by the increase in its porous characteristics due to differences in the Ca/P ratio.
      4  27
  • Publication
    Physical, thermal transport, and compressive properties of epoxy composite filled with graphitic- and ceramic-based thermally conductive nanofillers
    ( 2022)
    Siti Salmi Samsudin
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    ; ; ;
    Mariatti Jaafar
    ;
    Hassan A. Alshahrani
    Epoxy polymer composites embedded with thermally conductive nanofillers play an important role in the thermal management of polymer microelectronic packages, since they can provide thermal conduction properties with electrically insulating properties. An epoxy composite system filled with graphitic-based fillers; multi-walled carbon nanotubes (MWCNTs), graphene nanoplatelets (GNPs) and ceramic-based filler; silicon carbide nanoparticles (SiCs) was investigated as a form of thermal-effective reinforcement for epoxy matrices. The epoxy composites were fabricated using a simple fabrication method, which included ultrasonication and planetary centrifugal mixing. The effect of graphite-based and ceramic-based fillers on the thermal conductivity was measured by the transient plane source method, while the glass transition temperature of the fully cured samples was studied by differential scanning calorimetry. Thermal gravimetric analysis was adopted to study the thermal stability of the samples, and the compressive properties of different filler loadings (1–5 vol.%) were also discussed. The glass temperatures and thermal stabilities of the epoxy system were increased when incorporated with the graphite- and ceramic-based fillers. These results can be correlated with the thermal conductivity of the samples, which was found to increase with the increase in the filler loadings, except for the epoxy/SiCs composites. The thermal conductivity of the composites increased to 0.4 W/mK with 5 vol.% of MWCNTs, which is a 100% improvement over pure epoxy. The GNPs, SiCs, and MWCNTs showed uniform dispersion in the epoxy matrix and well-established thermally conductive pathways.
      1  13
  • Publication
    Physical, thermal transport, and compressive properties of epoxy composite filled with graphitic- and ceramic-based thermally conductive nanofillers
    ( 2022)
    Siti Salmi Samsudin
    ;
    ; ; ;
    Mariatti Jaafar
    ;
    Hassan A. Alshahrani
    Epoxy polymer composites embedded with thermally conductive nanofillers play an important role in the thermal management of polymer microelectronic packages, since they can provide thermal conduction properties with electrically insulating properties. An epoxy composite system filled with graphitic-based fillers; multi-walled carbon nanotubes (MWCNTs), graphene nanoplatelets (GNPs) and ceramic-based filler; silicon carbide nanoparticles (SiCs) was investigated as a form of thermal-effective reinforcement for epoxy matrices. The epoxy composites were fabricated using a simple fabrication method, which included ultrasonication and planetary centrifugal mixing. The effect of graphite-based and ceramic-based fillers on the thermal conductivity was measured by the transient plane source method, while the glass transition temperature of the fully cured samples was studied by differential scanning calorimetry. Thermal gravimetric analysis was adopted to study the thermal stability of the samples, and the compressive properties of different filler loadings (1–5 vol.%) were also discussed. The glass temperatures and thermal stabilities of the epoxy system were increased when incorporated with the graphite- and ceramic-based fillers. These results can be correlated with the thermal conductivity of the samples, which was found to increase with the increase in the filler loadings, except for the epoxy/SiCs composites. The thermal conductivity of the composites increased to 0.4 W/mK with 5 vol.% of MWCNTs, which is a 100% improvement over pure epoxy. The GNPs, SiCs, and MWCNTs showed uniform dispersion in the epoxy matrix and well-established thermally conductive pathways.
      1  16
  • Publication
    Toughening mechanism of thermoplastic starch nano-biocomposite with the hybrid of nanocellulose/nanobentonite
    (Elsevier, 2023)
    Lai Di Sheng
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    ; ;
    Mariatti Jaafar@Mustapha
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    ;
    High flexibility and toughness are key criteria for an effective bioplastic packaging film. However, in most studies, the flexibility of thermoplastic starch (TPS) films is always neglected when targeting their tensile strength improvement. Low film flexibility has limited the development of TPS films in replacing the petrochemical-based plastic packaging films. In this communication, we report a method to produce thermoplastic corn starch (TPCS) films with excellent mechanical strength, high flexibility and high toughness through the hybridization of two natural nanofillers: nanobentonite and nanocellulose. The synergistic effect of the hybrid nanofillers can be observed through the arrangement of alternating nacre structures where the nanobentonite silicate layers are responsible for mechanical strength, while the nanocellulose promotes free volume in the TPCS matrix and triggers high film elongation at break. Structural, morphological, and thermomechanical analysis were conducted, and the detailed strengthening mechanism of the TPCS hybrid nano-biocomposite films was revealed.
      5  31