Syarifah Nuraqmar Syed Mahamud
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Syarifah Nuraqmar Syed Mahamud
Official Name
Syarifah Nuraqmar, Syed Mahamud
Alternative Name
Mahamud, S. N.S.
Syed Mahamud, Syarifah Nuraqmar
Main Affiliation
Scopus Author ID
57220196221

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Electrical conductivity of poly(hydroxybutyrate-co-hydroxyvalerate)/ graphene biocomposites produced via different solvent

2021-05-03 , Syarifah Nuraqmar Syed Mahamud , Mohd Hanif Mohd Pisal , Koh J.H. , Jalil J.A.

Poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) is among the most promising polymers used in a variety of applications, owing to its low cost, biodegradability, and nontoxicity. However, PHBV is electrically insulating; hence, limits its use in biomedical applications. This study demonstrates a straightforward and environment-friendly method to fabricate and modify the electrical conductivity of PHBV-based biocomposites by incorporating graphene (G) as conductive filler. PHBV/G bicomposite films were fabricated using acetic acid as an alternative to conventional solvents such as chloroform. The electrical conductivity of the biocomposite films with various loadings of graphene (0- 5 wt.%) was investigated by a two-point probe. It was discovered that, PHBV/G biocomposites at 5 wt.% graphene loading possess the highest electrical conductivity irrespective of the type of solvents used. Meanwhile, acetic acid casted PHBV/G biocomposite films have a greater electrical conductivity compared to chloroform casted PHBV/G biocomposite films.

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Effect of graphene nanoplatelet addition on the electrical conductivity of poly(hydroxybutyrateco-hydroxyvalerate) biocomposites

2021-11-12 , Syarifah Nuraqmar Syed Mahamud , Ganesan O. , Mohd Hanif Mohd Pisal , Rabat N.E.

Poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) is one of the most promising biodegradable polymers used in many applications due to its biodegradability and non-toxicity. However, the usage of PHBV in electronic, biomedical, and biosensor applications has been limited due to its poor electrical properties. This study shows a simple method of producing and enhancing the electrical conductivity of PHBV-based biocomposites by adding graphene nanoplatelet (GNP) as a conductive filler. The biocomposite films were prepared using the solvent casting method, consist of five GNP loading (0-5 wt. %). The prepared PHBV/GNP biocomposites show enhanced electrical conductivity compared to neat PHBV. PHBV/GNP biocomposite with 5 wt. % filler loading exhibits the highest electrical conductivity at 3.83 × 10-3 S/cm. Higher crystalline regions in the PHBV/GNP biocomposites have facilitated the transfer of electrons between PHBV, resulting in the formation of conductive biocomposites, as evident from X-ray diffraction (XRD) characterization.

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Tensile and morphology properties of polylactic acid/ treated typha latifolia composites

2013 , Muthmirah Ibrahim , Jalilah Abd Jalil , Syarifah Nuraqmar Syed Mahamud , Yusrina Mat Daud , Salmah Husseinsyah , Muhammad Rafi’ Yahya

This paper is focused to investigate the effect of treated natural fiber (typha latifolia) content on tensile and morphology properties of polylactic acid (PLA)/treated typha latifolia (T-TyLa) composites. The composite was compounded using heated two roll mill and the composite samples were prepared through compression molding. Tensile test and scanning electron microscopy (SEM) analysis were carried out to study the properties of PLA/T-TyLa composites. The results showed that the tensile strength of PLA/T-TyLa composites was decreased for about 43% with initial addition of T-TyLa content. The tensile modulus of the composites was increased (23%-91%) with increasing of fiber content. However, increased in fiber content reduced the elongation at break for about 53%-67% of PLA/T-TyLa composites. The optimum increment was obtained at 30 wt% of fiber content. SEM results showed that fiber dispersion was better for PLA/T-TyLa composites at lower fiber content.

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Effect of sulphur vulcanization system on physical, morphological and thermal properties of natural rubber latex foam

2022-05-18 , Mohammad Syahrin Smail , Zunaida Zakaria , Hakimah Osman , Syarifah Nuraqmar Syed Mahamud , Munusamy Y.

Recently, several research studies have been implemented using sodium bicarbonate (NaHCO3) as a blowing agent on rubber foams, yet none has been found in natural rubber latex foam (NRLF). The use of NaHCO3 as a blowing agent in NRLF prepared by the Dunlop process can potentially develop greener foaming processes and more environmentally friendly foam in the industry of latex foam. This novel method is designed to manage the reduction of harmful waste disposal associated typically in producing the NRLF product which is useful for industry purposes. Hence, this research is presented to investigate the physical properties of NRLF such as relative foam density, crosslink density, average cell diameter, and thermogravimetric analysis (TGA) based on the influences of different sulphur vulcanization systems via conventional vulcanization (CV) system and efficient vulcanization (EV) system. The relative density and crosslink density were increased with an increase in NaHCO3 concentration with the CV system exhibiting higher value than the EV system. For average cell diameter, the results showed a decrease in both systems with the EV system having higher value than the CV system. Thermal stability from the TGA results was also improved at higher NaHCO3 concentration and for the use of the CV system as a foaming approach, the CV system has higher thermal stability than the EV system.

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Sodium alginate/graphene nanoplatelet nanocomposites effect of crosslinker and graphene nanoplatelet loading

2024-12 , Kean Chong Lim , Syarifah Nuraqmar Syed Mahamud , Muhammad Afiq Zikry Badrolhisham

In this article, the effect of crosslinker and filler loading on the properties of sodium alginate/graphene nanoplatelet (SA/GNP) nanocomposites is investigated. The nanocomposites samples were prepared using the solvent casting method. Swelling tests were performed to measure the degree of swelling. It was found that the degree of swelling increased with a longer immersion time in the 0.2M concentration of CaCl2. Interestingly, only a 12-minute immersion time in the 0.8M concentration of CaCl2 resulted in the lowest degree of swelling, which was 93.69%. Analysis of the gel fraction showed an increase in gel content at higher CaCl2 concentrations. To crosslink the SA/GNP nanocomposites, a concentration of 0.8 M CaCl2 and an immersion time of 12 minutes were selected. When the mechanical properties of SA with different CaCl2 concentrations were investigated, it was found that SA crosslinked at the 0.8M concentration had a higher elastic modulus than the 0.2M concentration of CaCl2, which was probably due to the higher crosslinking density. The mechanical properties of SA/GNP nanocomposites were found to decrease with decreasing GNP loading, which can be attributed to the presence of GNP. In addition, higher GNP loading resulted in improved electrical conductivity of the SA/GNP nanocomposites. X-ray diffraction (XRD) analysis proved that the crystallinity of SA increased with longer immersion times and the addition of GNP. Fourier transform infrared spectroscopy (FTIR) showed no significant changes in the peak characteristics of SA when the concentration of CaCl2, immersion time and GNP loading increased.

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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.

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Preparation of Carbon Nanotubes/Alumina Hybrid-Filled Phenolic Composite with Enhanced Wear Resistance

2023-04-01 , Siti Shuhadah Md Saleh , Mohd Firdaus Omar , Akil H.M. , Kudus M.H.A. , Mohd. Mustafa Al Bakri Abdullah , Sandu A.V. , Vizureanu P. , Khairul Anwar Abdul Halim , Mohamad Syahmie Mohamad Rasidi , Syarifah Nuraqmar Syed Mahamud , Sandu I. , Nosbi N.

Hybrid fillers can be produced via various methods, such as physical mixing and chemical modification. However, there is a limited number of studies on the effect of hybridisation on the mechanical performance of hybrid filler-reinforced polymer composites, especially in the context of wear performance. This study investigated the wear resistance of carbon nanotubes (CNTs)/alumina hybrid-filled phenolic composite, where two hybrid methods were used to produce the CNTs/alumina hybrid filler. The CNTs/alumina (CVD hybrid) was synthesised using the chemical vapour deposition (CVD) method, whereas the CNTs-/alumina (physically hybrid) was prepared using the ball milling method. The CNTs/alumina hybrid filler was then used as a filler in the phenolic composites. The composites were prepared using a hot mounting press and then subjected to a dry sliding wear test using a pin-on-disc (POD) tester. The results show that the composite filled with the CVD hybrid filler (HYB composite) had better wear resistance than the composite filled with physically hybrid filler (PHY composite) and pure phenolic. At 5 wt%, the HYB composite showed a 74.68% reduction in wear, while the PHY composite showed a 56.44% reduction in wear compared to pure phenolic. The HYB composite exhibited the lowest average coefficient of friction (COF) compared to the PHY composite and pure phenolic. The average COF decreased with increasing sliding speeds and applied loads. The phenolic composites’ wear and average COF are in the order HYB composite < PHY composite < pure phenolic under all sliding speeds and applied loads.

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The potential of chitosan-polygonum minus leaf mediated silver-nanoparticles composite as green conductive biofilm

2024-12 , Mohd Hanif Mohd Pisal , Jalilah Abd Jalil , Haiza Haroon , Muhammad Nabil Fikri Abd Nasir , Syarifah Nuraqmar Syed Mahamud , Zhi-Fu Lin

Silver-nanoparticles (AgNPs) from leaf extract have gained considerable interest from years ago until recently. However, the potential of green-synthesised AgNPs as a conductive filler in polymer biocomposites has not been widely investigated. Herein, a series of biopolymer-silver nanoparticle films were prepared by dispersing the suspension of Polygonum minus leaf mediated AgNPs into chitosan (CS) matrix via solution casting. In this work, the physicochemical properties of the composite films were evaluated, and structural property was analysed by Fourier transform infrared (FTIR) spectroscopy. The electrical conductivity and surface morphology were investigated by two-point probe and scanning electron microscopy (SEM), respectively. From the evaluation of moisture uptake, solubility and degradation tests, the rate of moisture uptake reduced as AgNPs concentration increased whereas the solubility and degradation rate increased with increasing addition of AgNPs. The FTIR analysis confirmed that there was no new covalent bond formed and suggested that AgNPs interact non-covalently with amine and hydroxyl groups of chitosan matrix. The conductivity of the CS-AgNPs films increased with one-order magnitude from 10-8 to 10-7 S/cm compared to pristine CS film. The percolation threshold was achieved at 20 wt% of AgNPs and the highest conductivity was achieved at 30 wt% AgNPs with the conductivity value of 3.20 x 10-7 S/cm. SEM micrographs revealed that the composite film with 30 wt% AgNPs exhibited smooth and homogeneous surface which agrees well with the conductivity results. This CS-Polygonum minus leaf mediated AgNPs composite film shows potential as an alternative for biodegradable biomedical implants, smart packaging and wearable electronics applications.

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Influence of filler loading and in situ salicylic acid treatment on corn husk fiber filled poly(Hydroxybutyrate-co-valerate)

2020-07-09 , Syarifah Nuraqmar Syed Mahamud , Abdullah N.H. , Mohd Hanif Mohd Pisal

The effect of filler loading and in situ salicylic acid treatment on the mechanical properties and morphology of poly(hydroxybutyrate-co-valerate)/ corn husk fiber (PHBV/CHF) biocomposites was studied. Both untreated and salicylic acid treated PHBV/CHF biocomposites were prepared by using heated two roll mill followed by compression moulding. It was found that the addition of CHF to PHBV biocomposites increased the tensile strength and Young's modulus while the elongation at break decreased. Salicylic acid treated PHBV/CHF biocomposite display superior tensile strength and Young's modulus than untreated PHBV/CHF biocomposite due to the enhanced filler-matrix interaction. The better interfacial adhesion between CHF and PHBV matrix was confirmed through scanning electron microscope (SEM) analysis.

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Preparation of carbon nanotubes/alumina hybrid-filled phenolic composite with enhanced wear resistance

2023 , Siti Shuhadah Md Saleh , Mohd Firdaus Omar , Hazizan Md Akil , Muhammad Helmi Abdul Kudus , Mohd. Mustafa Al Bakri Abdullah , Andrei Victor Sandu , Petrica Vizureanu , Khairul Anwar Abdul Halim , Mohamad Syahmie Mohamad Rasidi , Syarifah Nuraqmar Syed Mahamud , Ion Sandu , Norlin Nosbi

Hybrid fillers can be produced via various methods, such as physical mixing and chemical modification. However, there is a limited number of studies on the effect of hybridisation on the mechanical performance of hybrid filler-reinforced polymer composites, especially in the context of wear performance. This study investigated the wear resistance of carbon nanotubes (CNTs)/alumina hybrid-filled phenolic composite, where two hybrid methods were used to produce the CNTs/alumina hybrid filler. The CNTs/alumina (CVD hybrid) was synthesised using the chemical vapour deposition (CVD) method, whereas the CNTs-/alumina (physically hybrid) was prepared using the ball milling method. The CNTs/alumina hybrid filler was then used as a filler in the phenolic composites. The composites were prepared using a hot mounting press and then subjected to a dry sliding wear test using a pin-on-disc (POD) tester. The results show that the composite filled with the CVD hybrid filler (HYB composite) had better wear resistance than the composite filled with physically hybrid filler (PHY composite) and pure phenolic. At 5 wt%, the HYB composite showed a 74.68% reduction in wear, while the PHY composite showed a 56.44% reduction in wear compared to pure phenolic. The HYB composite exhibited the lowest average coefficient of friction (COF) compared to the PHY composite and pure phenolic. The average COF decreased with increasing sliding speeds and applied loads. The phenolic composites’ wear and average COF are in the order HYB composite < PHY composite < pure phenolic under all sliding speeds and applied loads.

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