Midhat Nabil Ahmad Salimi
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Midhat Nabil Ahmad Salimi
Official Name
Midhat Nabil, Ahmad Salimi
Alternative Name
Ahmad Salimi, Midhat Nabil
Salimi, Midhat Nabil
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Scopus Author ID
54788410200

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  • Publication
    Toughening mechanism of thermoplastic starch nano-biocomposite with the hybrid of nanocellulose/nanobentonite
    (Elsevier, 2023)
    Lai Di Sheng
    ;
    Azlin Fazlina Osman
    ;
    Sinar Arzuria Adnan
    ;
    Mariatti Jaafar@Mustapha
    ;
    Ismail Ibrahim
    ;
    Midhat Nabil Ahmad Salimi
    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
  • Publication
    Influence of carbonization conditions and temperature variations on the characteristics of coconut shell carbon
    ( 2024-03)
    Yee Wen Yap
    ;
    Nurul Najiha Abu Bakar
    ;
    Norsuria Mahmed
    ;
    Midhat Nabil Ahmad Salimi
    ;
    Siti Norsaffirah Zailan
    ;
    Azlin Fazlina Osman
    ;
    Kamrosni Abdul Razak
    ;
    Shayfull Zamree Abd. Rahim
    ;
    Mohd Yusry Mohamad Yunus
    This research aims to study the impact of carbonization atmospheres (ambient and nitrogen) and temperature on the properties of the coconut shell carbon (CSC) formed. To characterize the properties of CSC, the char yield percentage was calculated. Scanning Electron Microscopy (SEM) was used to study the surface morphology of CSC while X-ray Diffraction (XRD) analysis was done to identify the degree of graphitization. The carbon formed by carbonization under the nitrogen atmosphere yields lower char percentages compared to the ambient atmosphere. When the carbonization temperature elevated, both atmospheres produced a lower char yield percentage. This result is aligned with the SEM analysis where more and larger pores were observed from the carbon produced at higher temperatures and the result was further enhanced under a nitrogen atmosphere. It was found that the char yield of CSC decreased from 20.9% to 11.4% when the carbonization temperature increased from 400°C to 1000°C under the ambient atmosphere. More significant changes were formed through the carbonization process under the nitrogen atmosphere (from 18.3% to 6.03%). Pores formed when the volatile materials are released due to the elevated carbonization temperature, resulting in a reduction in total weight thus, the char yield percentage. From the XRD, all CSC produced from both atmospheres with varying temperatures poses an amorphous XRD pattern. However, the right shifted peak and the presence of an additional peak of ~40° suggest that under different temperatures and atmospheres, the crystallinity of the CSC produced was affected. This research provides insight for optimizing CSC production in the future to enhance the application of CSC.
      1  19
  • Publication
    Thermoplastic starch hybrid biocomposite films with improved strength and flexibility produced through crosslinking via carboxylic acid
    ( 2023)
    Di Sheng Lai
    ;
    Azlin Fazlina Osman
    ;
    Sinar Arzuria Adnan
    ;
    Ismail Ibrahim
    ;
    Mariatti Jaafar @ Mustapha
    ;
    Midhat Nabil Ahmad Salimi
    Thermoplastic starch (TPS) suffers from its intrinsic low mechanical strength and high brittleness due to its strong hydrogen bonding and low chain mobility. The conventional way to crosslink the TPS film can improve the strength and stiffness of the films, but usually reduces the flexibility of the film, and increases its brittleness. In this study, the incorporation of the hybrid nanofiller [1 wt% nanocellulose (C) and 4 wt% nano bentonite (B)] into the TPS proved to improve greatly the films’ strength and flexibility. The hybrid nanofillers with ratio 4B:1C was incorporated into the crosslinked thermoplastic corn starch (CR-TPCS) film to increase the its flexibility and toughness and produced a high mechanical strength fully biodegradable film. Two different aqueous carboxylic acids: citric acid (CA) and tartaric acid (TA) with different pH values (2,4,6) as the green crosslinker were employed. Substantial increase of tensile strength (3.98 to 9.17 MPa), Young’s modulus (9.10 to 46.30 MPa) and elongation at break (55.2 to 135.7%) was observed for the CA- 4B1C/pH2 films compared to the CR-TPCS films. The melting temperature (Tm) of the CA-4B1C/pH2 improved compared to the TPCS/4B1C (un-crosslinked) film due to its crosslinking effect. Meanwhile, the CA-4B1C films exhibited the highest degree of substitution and di-esterification with the lowest swelling and water solubility properties due to the formation of a special “bridge” structure between the CA, nanocellulose and plasticizer. The “bridge” structure developed between the TPCS chains serves as the toughener to motivate higher chain stress relaxation and load endurance. The crosslinked “bridge structure” also proved to effectively reduce the retrogradation phenomenal in the TPCS films. This combination method of hybridization and crosslinking is an efficient, low cost, and environmentally friendly technique to overcome the low flexibility and brittleness problem of the TPS based packaging film.
      2  36