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
    Improving flexural and dielectric 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
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Aslina Anjang Ab Rahman
    ;
    Muhammad Bisyrul Hafi Othman
    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.
  • Publication
    Enhancement of tensile properties of glass fibre epoxy laminated composites reinforced with carbon nanotubes interlayer using electrospray deposition
    ( 2021)
    Muhammad Razlan Zakaria
    ;
    Mohd Firdaus Omar
    ;
    Hazizan Md Akil
    ;
    Muhammad Bisyrul Hafi Othman
    ;
    Mohd. Mustafa Al Bakri Abdullah
    The introduction of carbon nanotubes (CNTs) onto glass fibre (GF) to create a hierarchical structure of epoxy laminated composites has attracted considerable interest due to their merits in improving performance and multifunctionality. Field emission scanning electron microscopy (FESEM) was used to analyze the woven hybrid GF-CNT. The results demonstrated that CNT was successfully deposited on the woven GF surface. Woven hybrid GF-CNT epoxy laminated composites were then prepared and compared with woven GF epoxy laminated composites in terms of their tensile properties. The results indicated that the tensile strength and tensile modulus of the woven hybrid GF-CNT epoxy laminated composites were improved by up to 9% and 8%, respectively compared to the woven hybrid GF epoxy laminated composites.
  • Publication
    Mechanical properties of rice husk (Oryza sativa) reinforced low density polyethylene composites for industrial injection moulded parts
    ( 2020-03-25)
    Jaya H.
    ;
    Nik Noriman Zulkepli
    ;
    Shayfull Zamree Abd. Rahim
    ;
    Mohd Firdaus Omar
    ;
    Rosniza Hamzah
    ;
    Dahham O.S.
    ;
    Umar M.U.
    Injection moulding is one of the most widely used processes in manufacturing plastic products, which has developed into a mature technology. Injection moulding is greatly preferred in manufacturing industry because it can produce complex-shaped plastic parts with good dimensional accuracy in very short cycle times. This article is concerned with the tensile properties of low-density polyethylene (LDPE) reinforced with alkaline treated rice husk (RH) specifically for injection moulded parts. In this study, the RH/LDPE composites with different loadings of 5, 10, and 15 wt.% treated RH were feed into injection moulding machine and the moulded parts were tested using conventional universal testing machine. The results showed that the tensile and flexural properties of the RH/LDPE composites were strongly affected by the filler loadings. Furthermore, all the tensile and flexural properties of the RH/LDPE composites showed increasing trend as the filler loading increased, up to 15 wt.% treated RH.
      1
  • Publication
    The effect of twin screw compounding parameters on the tensile properties of pineapple leaf/sea shell hybrid polymer composite using DOE approach
    ( 2020-11-24)
    Ching N.T.
    ;
    Khairul Anwar Abdul Halim
    ;
    Mohd Firdaus Omar
    ;
    Azlin Fazlina Osman
    ;
    Muhammad Salihin Zakaria
    Pineapple leaf and sea shell were used as natural fillers in this research due to its biodegradable nature, wide availability, continuous resources and low cost. This research work was carried out to investigate the effect of compounding process using twin screw extruder on the tensile performance of pineapple leaf / sea shell polymer composite using Design of Experiment (DOE) approach. A total of nine runs of were formulated and the resulitng hybrid composites were compounded using twin screw extruder. The short term tensile test was carried out to determine the tensile properties and the data were sunsequently analyse using DOE software. Pareto chart of the standardized effect and the main effect plot were employed to investigate the relationship between processing parameters and the tensile performance of the hybrid composite systems. Based on the initial DOE analysis, it is shown that compounding parameters had influenced the final mechanical behavior of the hybrid composites.
      1  30
  • Publication
    An alkaline deep eutectic solvent based on potassium carbonate and glycerol as pretreatment for the isolation of cellulose nanocrystals from empty fruit bunch
    ( 2020-02-01)
    Gan P.G.
    ;
    Sam Sung Ting
    ;
    Muhammad Faiq Abdullah
    ;
    Mohd Firdaus Omar
    ;
    Tan L.S.
    Cellulose nanocrystals (CNC) were successfully isolated from oil palm empty fruit bunch (EFB) using sulphuric acid hydrolysis preceded by alkaline deep eutectic solvent (DES) pretreatment and bleaching. In this study, an alkaline DES consisting of potassium carbonate and glycerol (molar ratio of 1:7) was used as the pretreatment solvent to promote the dissolution of lignin and hemicellulose. The processing parameters of acid hydrolysis were optimized using Box-Behnken Design. The results showed that the yield of CNC was 37.1%, under the optimal conditions of 60.0 wt% acid concentration at 46.1 °C for 58.5 min. The field emission scanning electron microscopy (FESEM), chemical composition analysis, and Fourier transform infrared (FTIR) results indicated that unwanted impurities, such as hemicellulose and lignin, were efficiently eliminated from the raw EFB fibers by DES pretreatment and bleaching. The average diameter of CNC was less than 10 nm. The raw EFB fiber, treated cellulose, and CNC showed crystallinities of 38.7%, 51.2%, and 65.3%, respectively. The CNC had lower thermal stability, which was ascribed to the sulphate group present on the CNC surface.
      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
    Network Structure and Mechanical Properties of Flexible Electronic Interconnects based on Linear Low-Density Polyethylene (LLDPE) and Liquid Silicone Rubber (LSR) Conductive Polymer Composites
    ( 2024-03-01)
    Khairul Anwar Abdul Halim
    ;
    Mohd Arif Anuar Mohd Salleh
    ;
    Badrul F.
    ;
    Azlin Fazlina Osman
    ;
    Mohd Firdaus Omar
    ;
    Suhaimi A.S.
    ;
    Muhammad Salihin Zakaria
    Conductive polymer composites (CPCs) with the ability to maintain high conductivity whilst remaining flexible at various operating temperatures and conditions have gained interest as potential materials for electronic interconnect applications. The ability of a polymer matrix to conduct electricity is mainly dependent on the conductive filler loadings as well as the formation of network paths within the CPCs. The main aim of this research work was to establish and understand the correlation between the network structure formation and mechanical properties of linear low-density polyethylene/copper (LLDPE/Cu) and liquid silicone rubber/copper (LSR/Cu) CPCs. Various techniques such as electron microscopy, thermal studies, four-point probe, and tensile testing were employed in this study. Furthermore, selected samples were characterized and tested using synchrotron micro-x-ray fluorescence (XRF) technique and dynamic mechanical analysis (DMA). It was found that the electrical conductivity of the CPCs increased with increasing filler loadings. Addition of Cu filler had a marginal effect on the tensile strength of both LLDPE/Cu and LSR/Cu CPCs. Nevertheless, it was found that the elongation at break for LLDPE/Cu consistently increased with the addition of Cu whereas, for LSR/Cu samples, the elongation at break decreased with the addition of Cu at various loadings. The scanning electron microscopy (SEM) micrographs obtained show that the particles of Cu were closer to one another at higher filler loadings. The data obtained revealed the potential for utilizing CPCs as flexible interconnects suitable for advanced electronic applications.
      1
  • Publication
    SFTA and GLCM via LDA Classifier for Skin Cancer Detection
    ( 2020-12-18)
    Mohd Firdaus Omar
    ;
    Muhammad Naufal Mansor
    ;
    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.
      2  20
  • Publication
    Micromechanical modeling of polyamide 11 nanocomposites properties using composite theories
    ( 2023)
    Khairul Anwar Abdul Halim
    ;
    James E. Kennedy
    ;
    Mohd Arif Anuar Mohd Salleh
    ;
    Azlin Fazlina Osman
    ;
    Mohd Firdaus Omar
    ;
    N.M. Sunar
    The use of organically modified clays as nano-reinforcement in polymer matrices is widely investigated owing to their remarkable reinforcement at low filler loading. In this body of work, the nanocomposites were prepared by melt blending nanoclay with polyamide 11 (PA 11) utilising a twin-screw extruder in order to maximise the dispersion of clay particles within the matrix during compounding. The main aim of the work was to study the reinforcing effect of nanoclay within PA 11 using two micromechanical model namely Halpin-Tsai and Mori-Tanaka composite theories. These theories were used to predict the effective tensile modulus of PA 11 nanocomposites and the results were compared to the experimental data. In addition, the Halpin-Tsai model was used to predict the storage modulus and heat distortion temperature (HDT) of PA 11 nanocomposites. It was found that the tensile modulus for nanocomposites with a high clay aspect ratio exhibits up to 10% higher when compared to the nanocomposites with lower clay aspect ratio. Thus, it is believed that the combination of clay aspect ratio and modulus contributes to the super reinforcing effect of nanoclay within the PA 11 matrix.
      1  18
  • Publication
    Influence of filler surface modification on static and dynamic mechanical responses of rice husk reinforced linear low-density polyethylene composites
    ( 2021)
    Mohd Firdaus Omar
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Sam Sung Ting
    ;
    B. Jeż
    ;
    M. Nabiałek
    ;
    Hazizan Md Akil
    ;
    Nik Noriman Zulkepli
    ;
    Shayfull Zamree Abd. Rahim
    ;
    Azida Azmi
    Filler surface modification has become an essential approach to improve the compatibility problem between natural fillers and polymer matrices. However, there is limited work that concerns on this particular effect under dynamic loading conditions. Therefore, in this study, both untreated and treated low linear density polyethylene/rice husk composites were tested under static (0.001 s–1, 0.01 s–1 and 0.1 s–1) and dynamic loading rates (650 s–1, 900 s–1 and 1100 s–1) using universal testing machine and split Hopkinson pressure bar equipment, respectively. Rice husk filler was modified using silane coupling agents at four different concentrations (1, 3, 5 and 7% weight percentage of silane) at room temperature. This surface modification was experimentally proven by Fourier transform infrared and Field emission scanning electron microscopy. Results show that strength properties, stiffness properties and yield behaviour of treated composites were higher than untreated composites. Among the treated composites, the 5% silane weight percentage composite shows the optimum mechanical properties. Besides, the rate of sensitivity of both untreated and treated composites also shows great dependency on strain rate sensitivity with increasing strain rate. On the other hand, the thermal activation volume shows contrary trend. For fracture surface analysis, the results show that the treated LLDPE/RH composites experienced less permanent deformation as compared to untreated LLDPE/RH composites. Besides, at dynamic loading, the fracture surface analysis of the treated composites showed good attachment between RH and LLDPE.
      1  16