Mohd Firdaus Omar
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Preferred name
Mohd Firdaus Omar
Official Name
Mohd Firdaus, Omar
Alternative Name
Omar, Mohd Firdaus
Mohd, Firdaus Omar
Omar, M. F.
Omar, Mohdfirdaus
Omar, Mohd F.
Main Affiliation
Scopus Author ID
36149536300
Researcher ID
U-8459-2019

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  • Publication
    Study of carbon nanotubes stability in different types of solvents for electrospray deposition method
    ( 2020-12-01)
    Zakaria M.R.
    ;
    Mohd Firdaus Omar
    ;
    Akil H.M.
    ;
    Mohd. Mustafa Al Bakri Abdullah
    Electrospray deposition (ESD) required a dispersing agent that could form a stable suspension of solution for carbon nanotubes (CNT) deposition on the carbon fiber (CF). The N-methyl-2-pyrrolodone (NMP), dimethylformamide (DMF) and tetrahydrofuran (THF) solvents were investigated for dispersion of CNT. Based on the optical observation, zeta potential and UV-Vis spectroscopy, all findings indicate that the CNT dispersed in NMP has better dispersion and higher stability. Analysis by extreme high-resolution field emission scanning electron microscope (XHR-FESEM) shows the CNT was homogeneously distributed and covered the entire surface of the CF.
      1
  • Publication
    Self-healable and recyclable nitrile rubber based on thermoreversible ionic crosslink network
    ( 2022-04-15)
    Mohd Hafiz Zainol
    ;
    Ariff Z.M.
    ;
    Mohd Firdaus Omar
    ;
    Ping T.M.
    ;
    Shuib R.K.
    In this work, commercial carboxylated nitrile butadiene rubber (XNBR) was ionically crosslinked with zinc thiolate forming reversible ionic salt bonding between carboxy groups (COOH) in XNBR chains and Zn2+ ions from zinc thiolate. The reversible nature of the ionic crosslinks allows rearrangement of rubber molecular chains under an external heat and provides self-healing capability to the materials. The amount of zinc thiolate was varied at five levels (10, 20, 30, 40, and 50 per hundred rubber (phr) to assess the maximum reaction between COOH and Zn2+ ion for the formation of ionic crosslink networks. Evidence that ionic crosslinks formed within the materials was determined by the increased of curing torque and the chemical interaction was identified by Fourier transform infrared spectroscopy. An equilibrium swelling testing quantitatively measured the ionic crosslink density within the material and XNBR with 30-phr zinc thiolate showed the highest ionic crosslink density. The results revealed that, damaged XNBR with 30 phr zinc thiolate able to recover 98% of its initial properties under thermal healing at 150°C for 10 min. Furthermore, the material can be reprocessed and recycled for three times without compromising its initial properties. Perhaps, the tensile strength increased 360% at approximately 23 MPa, after third recycling process. In addition, the self-healing XNBR also have excellent weldability on the damage sample, which shows high potential for repairing of existing rubber products installed in heavy engineering applications.
      13  1
  • Publication
    HIERARCHICAL CARBON FIBER-CARBON NANOTUBES BY USING ELECTROSPRAY DEPOSITION METHOD WITH PRESERVED TENSILE PROPERTIES
    ( 2022-01-01)
    Muhammad Razlan Zakaria
    ;
    Akil H.M.
    ;
    Mohd Firdaus Omar
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Shayfull Zamree Abd. Rahim
    ;
    Nabiałek M.
    ;
    Wysłocki J.J.
    In this study, the electrospray deposition (esD) method was used to deposit carbon nanotubes (cNT) onto the surfaces of carbon fibers (cF) in order to produce hybrid carbon fiber-carbon nanotubes (cF-cNT) which is rarely reported in the past. extreme high-resolution field emission scanning electron microscopy (XHR-FeseM), high-resolution transmission electron microscopy (HRTeM) and x-ray photoelectron spectroscopy (XPs) were used to analyse the hybrid carbon fiber-carbon nanotube (cF-cNT). The results demonstrated that cNT was successfully and homogenously distributed on the cF surface. Hybrid cF-cNT was then prepared and compared with cF without cNT deposition in terms of their tensile properties. statistically, the tensile strength and the tensile modulus of the hybrid cF-cNT were increased by up to 3% and 25%, respectively, as compared to the cF without cNT deposition. The results indicated that the esD method did not cause any reduction of tensile properties of hybrid cF-cNT. based on this finding, it can be prominently identified some new and significant information of interest to researchers and industrialists working on cF based products.
      1
  • Publication
    Self-healable and recyclable nitrile rubber based on thermoreversible ionic crosslink network
    ( 2022-04-15)
    Zainol M.H.
    ;
    Ariff Z.M.
    ;
    Mohd Firdaus Omar
    ;
    Ping T.M.
    ;
    Shuib R.K.
    In this work, commercial carboxylated nitrile butadiene rubber (XNBR) was ionically crosslinked with zinc thiolate forming reversible ionic salt bonding between carboxy groups (COOH) in XNBR chains and Zn2+ ions from zinc thiolate. The reversible nature of the ionic crosslinks allows rearrangement of rubber molecular chains under an external heat and provides self-healing capability to the materials. The amount of zinc thiolate was varied at five levels (10, 20, 30, 40, and 50 per hundred rubber (phr) to assess the maximum reaction between COOH and Zn2+ ion for the formation of ionic crosslink networks. Evidence that ionic crosslinks formed within the materials was determined by the increased of curing torque and the chemical interaction was identified by Fourier transform infrared spectroscopy. An equilibrium swelling testing quantitatively measured the ionic crosslink density within the material and XNBR with 30-phr zinc thiolate showed the highest ionic crosslink density. The results revealed that, damaged XNBR with 30 phr zinc thiolate able to recover 98% of its initial properties under thermal healing at 150°C for 10 min. Furthermore, the material can be reprocessed and recycled for three times without compromising its initial properties. Perhaps, the tensile strength increased 360% at approximately 23 MPa, after third recycling process. In addition, the self-healing XNBR also have excellent weldability on the damage sample, which shows high potential for repairing of existing rubber products installed in heavy engineering applications.
      1
  • Publication
    Improving flexural and dielectric properties of carbon fiber epoxy composite laminates reinforced with carbon nanotubes interlayer using electrospray deposition
    ( 2020-01-01)
    Muhammad Razlan Zakaria
    ;
    Hazizan Md Akil
    ;
    Mohd Firdaus Omar
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Rahman, Aslina Anjang Ab
    ;
    Othman, Muhammad Bisyrul Hafi
    The electrospray deposition method was used to deposit carbon nanotubes (CNT) onto the surfaces of woven carbon fiber (CF) to produce woven hybrid carbon fiber-carbon nanotubes (CF-CNT). Extreme high-resolution field emission scanning electron microscopy (XHR-FESEM), X-ray diffraction (XRD), Raman spectroscopy and Fourier transform infrared spectroscopy (FT-IR) were used to analyze the woven hybrid CF-CNT. The results demonstrated that CNT was successfully and homogenously distributed on the woven CF surface. Woven hybrid CF-CNT epoxy composite laminates were then prepared and compared with woven CF epoxy composite laminates in terms of their flexural and dielectric properties. The results indicated that the flexural strength, flexural modulus and dielectric constant of the woven hybrid CF-CNT epoxy composite laminates were improved up to 19, 27 and 25%, respectively, compared with the woven CF epoxy composite laminates.
      2  1
  • Publication
    Enhancement of mechanical and thermal properties of carbon fiber epoxy composite laminates reinforced with carbon nanotubes interlayer using electrospray deposition
    ( 2020-11-01)
    Zakaria M.R.
    ;
    Md Akil H.
    ;
    Mohd Firdaus Omar
    ;
    Abdul Kudus M.H.
    ;
    Mohd Sabri F.N.A.
    ;
    Mohd. Mustafa Al Bakri Abdullah
    Carbon nanotubes (CNTs) was successfully deposited onto the surface of woven carbon fiber (CF) using the electrospray deposition method to produce a woven hybrid CF-CNT. The effect of voltage and spray times on the morphology of the woven hybrid CF-CNT have been studied. The voltage and spray time is crucial towards achieving a homogeneous CNT coating on the woven CF surface. The epoxy composite laminated with optimized woven hybrid CF-CNT and woven CF without the deposited CNTs were then prepared, and its tensile and thermal properties subsequently determined. The results showed that the woven hybrid CF-CNT epoxy composite laminates tensile strength increased by ~21%, its tensile modulus increased by ~37%, its interlaminar shear strength increased by ~25%, and its thermal conductivity increased by ~35% relative to that of the woven CF epoxy composite laminates.
      2