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
    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.
  • 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.
  • Publication
    SFTA and GLCM via LDA Classifier for Skin Cancer Detection
    ( 2020-12-18)
    Mohd Firdaus Omar
    ;
    Mansor M.N.
    ;
    Syahrul Affandi Saidi
    Skin cancer may be a serious tumor. This can be clearly seen through the mature, uncommon appearance of fur pathology, which has abnormal properties in complex situations, wrinkled or uncertain perimeters, and dual colors. A small number of tulle melanomas of uncertain diameter can imitate benign moles and cannot be perceived by optical inspection. The only assumption for analyzing them is through dermoscopy as an option. Original identification and medical surgery can alternative for the patients. Within this research a detection method through image processing with various feature extraction such as Gabor filter and Hu Moment were employed and substantially improves the diagnosis performance with 97% via LDA Classifier.
  • Publication
    New High Strength Water Retaining Interlocking Pavers Block for High Mechanical Performing Pavement and Reducing Runoff
    ( 2020-03-18)
    Muhd Afiq Hizami Abdullah
    ;
    Rashid N.A.
    ;
    Abdul Latif Abdul Rani
    ;
    Mohd Firdaus Omar
    Interlocking paver blocks are used widely at low speed traffics road especially surrounding building complexes. Interlocking paver blocks are easy to install and provide aesthetic finishing to the landscape. However, usage of interlocking blocks in large areas reduce ground permeability that lead to higher runoff. New interlocking paver blocks were investigated to reduce runoff and the effect on its mechanical performance. Two types of paver block produced which is paver block with permeable concrete and paver block with void in the center. The results show that the compressive strength for paver block with permeable concrete is averagely higher than paver block with void by 31.5% while the flexural strength of all samples were between 1.0 to 1.7 MPa. Paver block with void recorded highest reduction of runoff compared to paver block with permeable concrete which is 25.5%. This is in line with water infiltration test result. It was concluded that the water retaining performance of paver block increase with increment of void volume and increase in void volume caused reduction on compressive strength of interlocking blocks.
  • Publication
    The effect of synthesis parameter On HKUST-1 nanocomposites studied by FTIR characterisation and mechanical testing
    ( 2024-12)
    Syazwana Ahmad
    ;
    Mohd Firdaus Omar
    ;
    Khairul Anwar Abdul Halim
    ;
    Shayfull Zamree Abd. Rahim
    ;
    Sam Sung Ting
    ;
    E. M. Mahdi
    ;
    Hazizan Md Akil
    ;
    Muhammad Hafiz Hassan
    ;
    Norlin Nosbi
    ;
    Nurfina Yudasari
    In the present work, Hong Kong University of Science and Technology (HKUST-1) has been synthesised at room temperature with 1:0, 1:1 and 0:1 ratio of ethanol and water and reinforced into polyurethane. In order to understand the impact of synthesis parameters on HKUST-1 nanocomposites, an investigation was conducted using FTIR characterisation and mechanical testing. The objective was to examine the potential improvement of the reinforced polymer. The mechanical testing results were shown to be significantly influenced by the presence of HKUST-1 with 1:0 ratio of ethanol and water (sample A) into polyurethane (PU). The samples underwent Fourier Transform Infrared Spectroscopy (FTIR) analysis to determine the types of bonds within the polymer-MOF nanocomposites. It was observed that the reinforced nanoparticles did not undergo any chemical changes, as indicated by the recorded spectra, which can be related to the overlapping characteristics of HKUST-1 and PU. The findings indicate that the A/PU exhibited a notable impact in comparison to other materials, as evidenced by the results of the tensile test and nanoindentation study.
  • Publication
    Effect of Nitrate Acid Treated Dolomite on the Tensile Properties of Ultra-High Molecular Weight Polyethylene (UHMWPE) Composites
    ( 2024-01-01)
    Abdullah S.F.A.
    ;
    Saleh S.S.M.
    ;
    Nur Farahiyah Mohammad
    ;
    Syarifah Nuraqmar Syed Mahamud
    ;
    Mohd Firdaus Omar
    ;
    Akil H.M.D.
    ;
    Chang B.P.
    ;
    Saliu H.R.
    ;
    Rostam N.H.
    ;
    Gondro J.
    Ultra-High Molecular Weight Polyethylene (UHMWPE) polymers have been used in biomedical applications due to its biocompatibility, durability, toughness and high wear resistance. To enhance the mechanical properties, various types of minerals are commonly utilized as fillers in UHMWPE. One of the minerals is dolomite, which has been recognized as a valuable mineral with versatile applications, particularly in the field of biomedical applications. This paper presents the tensile properties of UHMWPE composites that filled with dolomite and treated-dolomite at various filler loading (i.e., 1-5 wt.%). Nitric acid and diammonium phosphate were used to treat the dolomite. From the results, the peaks of the FTIR spectrum displays carbonate (CO3–2), phosphate (PO4–3) and hydroxyl (OH–) groups in the ct-dolomite powder sample while the XRD pattern reveals that using dolomite treated with 1M nitric acid resulted in the presence of calcium hydroxide phosphate (Ca10(PO4)5(OH)) and MgO. For tensile strength, UHMWPE/ct-dolomite composites show better tensile strength than the pure UHMWPE composites. Treated improve the dolomite filler and resulted in significantly better matrix-filler interfacial interactions and improve the properties.
  • Publication
    Enhancement of mechanical and thermal properties of carbon fiber epoxy composite laminates reinforced with carbon nanotubes interlayer using electrospray deposition
    ( 2020)
    Muhammad Razlan Zakaria
    ;
    Hazizan Md Akil
    ;
    Mohd Firdaus Omar
    ;
    Muhammad Helmi Abdul Kudus
    ;
    Fatin Nur Amirah Mohd Sabri
    ;
    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.
  • Publication
    Investigation of Biosand Filter (BSF) on the Treatment Performance of Industrial Latex Wastewater
    ( 2024-01-01)
    Najihah Abdul Rashid
    ;
    Abdul Latif Abdul Rani
    ;
    Mohd Firdaus Omar
    ;
    Zainol N.A.
    ;
    Salwa Mohd Zaini Makhtar
    ;
    A B Wahab M.
    ;
    Nabilah Aminah Lutpi
    ;
    Farrah Aini Dahalan
    Biosand Filters (BSF) has great potential to improve the water quality. BSF is used extensively in the treatment of drinking water in rural areas because it is affordable, simple to use, and has a high removal efficiency. This study used actual latex effluent to examine the effectiveness of SBR. The growth of the biolayer in the BSF is also observed. This study analyzes consistent and stable results for COD, DO and NH4-N+. With removal performance ranging from 87 % to 99 %. DO value for BSF varied from lowest value of 1.5 mg/L to 8mg/L. Overall, the BSF was capable of producing treated water for water reclamation.
  • Publication
    Mechanical and dielectric properties of hybrid carbon nanotubes-woven glass fibre reinforced epoxy laminated composites via the electrospray deposition method
    ( 2021)
    Muhammad Razlan Zakaria
    ;
    Nur Aishahatul Syafiqa Mohammad Khairuddin
    ;
    Mohd Firdaus Omar
    ;
    Hazizan Md Akil
    ;
    Muhammad Bisyrul Hafi Othman
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Shayfull Zamree Abd. Rahim
    ;
    Sam Sung Ting
    ;
    Azida Azmi
    Herein, the effects of multi-walled carbon nanotubes (CNTs) on the mechanical and dielectric performance of hybrid carbon nanotube-woven glass fiber (GF) reinforced epoxy laminated composited are investigated. CNTs are deposited on woven GF surface using an electrospray deposition method which is rarely reported in the past. The woven GF deposited with CNT and without deposited with CNT are used to produce epoxy laminated composites using a vacuum assisted resin transfer moulding. The tensile, flexural, dielectric constant and dielectric loss properties of the epoxy laminated composites were then characterized. The results confirm that the mechanical and dielectric properties of the woven glass fiber reinforced epoxy laminated composited increases with the addition of CNTs. Field emission scanning electron microscope is used to examine the post damage analysis for all tested specimens. Based on this finding, it can be prominently identified some new and significant information of interest to researchers and industrialists working on GF based products
  • Publication
    Studies on factors affecting unconfined compressive strength of industrial rubber sludge containing heavy metals treated using ordinary Portland cement via stabilization/solidification technique
    ( 2020-12-18)
    Abdul Latif Abdul Rani
    ;
    Rashid N.A.
    ;
    Muhd Afiq Hizami Abdullah
    ;
    Mohd Firdaus Omar
    ;
    Salim A.S.
    ;
    Anuar N.A.I.
    High concentration of selected heavy metals within industrial rubber sludge collected from rubber industry wastewater treatment plant has classified the waste as scheduled waste. Special treatment to the waste by using ordinary Portland cement via solidification/stabilization (S/S) technique has been performed in laboratory scale. The objective of this research is to determine related factors that affect unconfined compressive strength (UCS) performance of stabilised/solidified (s/s) cube specimens which contains industrial rubber sludge waste. Other parameters observed include the curing condition (i.e. air and water immersion curing method), waste composition, specimen age and density. The prepared fresh mix were cast in plastic moulds in order to produce 50 mm3 cubical shape specimens and leaved to set approximately 24 to 48 hours. The prepared specimen batches are S1 (90% OPC + 10% waste), S2 (70% OPC + 30% waste), S3 (50% OPC + 50% waste). UCS was performed on respective specimen age of 7 and 28 days. Positive results were obtained as relatively the average compressive strength of 7 day air cured specimens reach 5.25 MPa, 5.28 MPa, and 2.16 MPa for S1, S2 and S3.While, 28 days air cured specimens results are 9.59 MPa, 8.01 MPa, and 1.46 MPa for S1, S2, and S3 respectively. As for water immersion, the compressive strengths are 8.19 MPa, 4.93 MPa, and 1.90 MPa for 7 days, and 7.75 MPa, 10.10 MPa, and 2.11 MPa for 28 days at respective S1, S2 and S3 sequence. As conclusion, the specimens prepared passed the minimum requirement for secured landfill disposal which is at 1 MPa.