Mohd. Mustafa Al Bakri Abdullah
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Preferred name
Mohd. Mustafa Al Bakri Abdullah
Official Name
Abdulah, Mohd. Mustafa Al Bakri
Alternative Name
Abdullah, M.M.A.
M.M.A. Abdullah
Mustafa Al Bakri, A. M.
Albakri Abdullah, M. M.
Main Affiliation
CeGeoGTech UniMAP
Scopus Author ID
53164519100

Research Output
Now showing 1 - 8 of 8
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The influence of heat treatment on the magnetic properties of the alloy Fe62Co10Y8B20 produced by the injection suction casting method

2020 , M. Talar , J. Gondro , P. Vizureanu , Mohd. Mustafa Al Bakri Abdullah , K. BÅ‚och

The paper presents studies of annealing effect on the magnetic properties of the bulk Fe62Co10Y8B20alloy in the form of rods. The thermal treatment was performed at the temperature well below the crystallization temperature. Structure, revealed by X-ray diffraction and Mössbauer spectroscopy and magnetic properties in high magnetic fields in the Fe62Co10Y8B20alloy after fabricated and after the annealing were studied. We have stated that the investigated alloy was fully amorphous. It is due to the stress relieving of the sample. Using a vibrating sample magnetometer the magnetization in high magnetic fields was studied. For both the sample after solidification and after heat treatment, the magnetization process in the area called "the approach to ferromagnetic saturation" is affected by free volumes. In addition, the heat treatment improved the magnetic properties and increased the packing density of atoms.

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Sustainable geopolymer adsorbents utilizing silica fume as a partial replacement for metakaolin in the removal of copper ion from synthesized copper solution

2025-07 , Pilomeena Arokiasamy , Mohd. Mustafa Al Bakri Abdullah , Eva Arifi , Noorina Hidayu Jamil , Md Azree Othuman Mydin , Andrei Victor Sandu , Shayfull Zamree Abd. Rahim , Shafiq Ishak

Biochar has great significance for controlling heavy metal pollution. Nevertheless, its application is impeded by certain shortcomings, such as a limited adsorption capacity, a slow adsorption rate, and poor reusability. Besides, the physical adsorption capacity of raw biochar to heavy metals is suboptimal. As a result, researchers prefer to use geopolymer-based adsorbents for the removal of heavy metals due to their excellent immobilization effect. However, no research has been done on the synthesis of geopolymer-based adsorbent using silica fume for heavy metal adsorption. Thus, the aim of this study is to partially replace metakaolin (MK) with silica fume (S1) (25, 50, 75 and 100 %) in geopolymer formulation at varied S:L ratio (0.4, 0.6, 0.8 and 1.0) to study the impact on the geopolymerization and its following properties in the removal efficiency of copper (Cu2 +). Characterization techniques such as Energy dispersive X-ray fluorescence (EDXRF), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Scanning electron microscope (SEM) and Energy dispersive X-ray spectroscopy (EDX) were used to study the physicochemical properties of the developed geopolymer. The concentration of Cu2+ before and after adsorption was determined by Atomic absorption spectroscopy (AAS) and the removal efficiency was calculated. Based on the experimental result, the geopolymer prepared with 25 % MK and 75 % S1 at S:L of 0.6 maintained the high removal efficiency of Cu2+ (99.62 %) with 100 % MK geopolymer (98.56 %). The generation of N-A-S-H gel with the 75 % replacement level of S1 producing more reactive Si and Al binding sites for Cu2+ adsorption. In addition, S1 contains exchangeable cations such as Ca2+, Mg2+ and Na+ which further promote the adsorption of Cu2+ by ion exchange. Moreover, the mechanisms such as chemical bonding and precipitation were involved in the adsorption of Cu2+. Hence, this research could serve as a basis for the development of solid waste based geopolymers that could remove heavy metal ions from aqueous solution.

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Influence of microparticles on setting time and micromorphology of coal ash geopolymers

2020 , D D Burduhos Nergis , P Vizureanu , D Èšopa , M G Minciuna , Mohd. Mustafa Al Bakri Abdullah

Geopolymers are inorganic materials with zeolites-like microstructure and mechanical properties similar to those of Ordinary Portland cement materials [1]. However, their properties are highly depending on the constituents (raw material and activator) characteristics, as well as, on the activation particularities (mixing parameters, curing time and temperature etc.). In order to explore the influence of partial replacement of coal ash with two types of fine aggregates (glass and sand microparticles) on micromorphology and setting time, four types of geopolymers were developed. The evaluations were performed by means of electronic microscopy and Vicat method. According to this study, the coal ash replacement with glass microparticles results in an increase in the initial and the final setting time, while the replacement of coal ash with sand particles show a significant decrease. Moreover, the microstructural analysis shows different behaviour, during activation, of the studied microparticles. The surface of the glass microparticles reacts in the alkaline environment, while the sand particles did not. Therefore, the increase of initial and final setting time can be correlated with the dissolution of Si-O from the glass particles, during geopolymerisation.

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Solidification/stabilization technology for radioactive wastes using cement: an appraisal

2023 , Ismail Luhar , Salmabanu Luhar , Mohd. Mustafa Al Bakri Abdullah , Andrei Victor Sandu , Petrica Vizureanu , Rafiza Abdul Razak , Dumitru Doru Burduhos-Nergis , Thanongsak Imjai

Across the world, any activity associated with the nuclear fuel cycle such as nuclear facility operation and decommissioning that produces radioactive materials generates ultramodern civilian radioactive waste, which is quite hazardous to human health and the ecosystem. Therefore, the development of effectual and commanding management is the need of the hour to make certain the sustainability of the nuclear industries. During the management process of waste, its immobilization is one of the key activities conducted with a view to producing a durable waste form which can perform with sustainability for longer time frames. The cementation of radioactive waste is a widespread move towards its encapsulation, solidification, and finally disposal. Conventionally, Portland cement (PC) is expansively employed as an encapsulant material for storage, transportation and, more significantly, as a radiation safeguard to vigorous several radioactive waste streams. Cement solidification/stabilization (S/S) is the most widely employed treatment technique for radioactive wastes due to its superb structural strength and shielding effects. On the other hand, the eye-catching pros of cement such as the higher mechanical strength of the resulting solidified waste form, trouble-free operation and cost-effectiveness have attracted researchers to employ it most commonly for the immobilization of radionuclides. In the interest to boost the solidified waste performances, such as their mechanical properties, durability, and reduction in the leaching of radionuclides, vast attempts have been made in the past to enhance the cementation technology. Additionally, special types of cement were developed based on Portland cement to solidify these perilous radioactive wastes. The present paper reviews not only the solidification/stabilization technology of radioactive wastes using cement but also addresses the challenges that stand in the path of the design of durable cementitious waste forms for these problematical functioning wastes. In addition, the manuscript presents a review of modern cement technologies for the S/S of radioactive waste, taking into consideration the engineering attributes and chemistry of pure cement, cement incorporated with SCM, calcium sulpho–aluminate-based cement, magnesium-based cement, along with their applications in the S/S of hazardous radioactive wastes.

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Characterisation at the bonding zone between fly ash based Geopolymer Repair Materials (GRM) and Ordinary Portland Cement Concrete (OPCC)

2020 , Warid Wazien Ahmad Zailani , Mohd. Mustafa Al Bakri Abdullah , Mohd Fadzil Arshad , Rafiza Abd Razak , Muhammad Faheem Mohd. Tahir , Remy Rozainy Mohd Arif Zainol , Marcin Nabialek , Andrei Victor Sandu , Jerzy J. Wysłocki , Katarzyna Błoch

In recent years, research and development of geopolymers has gained significant interest in the fields of repairs and restoration. This paper investigates the application of a geopolymer as a repair material by implementation of high-calcium fly ash (FA) as a main precursor, activated by a sodium hydroxide and sodium silicate solution. Three methods of concrete substrate surface preparation were cast and patched: as-cast against ordinary Portland cement concrete (OPCC), with drilled holes, wire-brushed, and left as-cast against the OPCC grade 30. This study indicated that FA-based geopolymer repair materials (GRMs) possessed very high bonding strength at early stages and that the behavior was not affected significantly by high surface treatment roughness. In addition, the investigations using scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) spectroscopy have revealed that the geopolymer repair material became chemically bonded to the OPC concrete substrate, due to the formation of a C–A–S–H gel. Fundamentally, the geopolymer network is composed of tetrahedral anions (SiO4)4− and (AlO4)5− sharing the oxygen, which requires positive ions such as Na+, K+, Li+, Ca2+, Na+, Ba2+, NH4+, and H3O+. The availability of calcium hydroxide (Ca(OH)2) at the surface of the OPCC substrate, which was rich in calcium ions (Ca2+), reacted with the geopolymer; this compensated the electron vacancies of the framework cavities at the bonding zone between the GRM and the OPCC substrate.

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The incorporation of Sodium Hydroxide (NaOH) concentration and CaO-Si components on ground granulated blast furnace slag geopolymers

2020 , Ikmal Hakem Aziz , Mohd. Mustafa Al Bakri Abdullah , Mohd Arif Anuar Mohd Salleh , Andrei Victor Sandu

This paper investigates the incorporation of sodium hydroxide (NaOH) concentration and CaO-Si component on ground granulated blast furnace slag geopolymers (GGBFS). An optimal mechanical property of GGBFS with various NaOH concentrations had been determined by performing a number of compressive strength tests. It was found that GGBFS with 10M NaOH concentration resulted in high compressive strength at 65.31 MPa after 28 days curing. The microstructure analysis of the GGBFS geopolymers using SEM and FTIR revealed the formation of calcium silicate hydrate (Ca5Si6O16(OH)2.4H2O) and calcium carbonate (CaCO3) phase within the geopolymer backbone chain. The optimum NaOH concentration allows the acceptable formation of CaO-Si bond on the GGBFS geopolymers main structure and thus leads to optimum compressive strength.

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Densification behavior and mechanical performance of Nepheline geopolymer ceramics: preliminary study

2023 , Nur Bahijah Mustapa , Romisuhani Ahmad , Mohd. Mustafa Al Bakri Abdullah , Wan Mastura Wan Ibrahim , Andrei Victor Sandu , Christina Wahyu Kartikowati , Puput Risdanareni , Wan Hasnida Wan Mohamed Saimi

Nepheline geopolymer ceramics have emerged as a promising sustainable alternative to traditional cementitious materials in various applications. As the sintering mechanism plays a crucial role in the densification and mechanical performance of ceramics, therefore, in this paper, a preliminary study was conducted to examine the effects of densification towards mechanical properties of geopolymer-based nepheline ceramics upon sintering. The said innovative geopolymer technology can convert raw materials of aluminosilicate activating with alkaline activator into ceramic-like materials requiring low temperatures. The experimental procedure includes the synthesis of nepheline geopolymer ceramics through the geopolymerization method, then sintered at different temperatures to explore the sintering behavior and its impact on the materials’ microstructure and mechanical performance. The densification behavior of nepheline geopolymer ceramics during sintering was analyzed by evaluating the changes in density, shrinkage, and porosity. The microstructural evolution and are determined by using SEM. The relationships between sintering conditions, microstructure, and mechanical performance were investigated to understand the underlying mechanisms affecting the material’s strength and durability. The geopolymer exhibited its highest flexural strength of 54.93 MPa when sintered at 1200 ℃, while the lowest strength of 6.07 MPa was observed at a sintering temperature of 200 ℃. The findings demonstrate a positive correlation between the sintering temperature and the flexural strength of the geopolymer ceramics, indicating that higher temperatures lead to increased strength. Ultimately, this knowledge can facilitate the broader utilization of nepheline geopolymer ceramics as sustainable materials in various engineering and construction applications.

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Influence of Co and Zr content on creation of Crystalline phases in rapidly-cooled, injection-cast alloys Fe70Zr8-xCoxNb2B20 (where x=0, 2, 4, 6 or 8)

2020 , M. Nabiałek , S. Walters , P. Vizureanu , Mohd. Mustafa Al Bakri Abdullah , B. Jeż

Rapid solidification techniques allow the manufacture of nanocrystalline alloys using a single-stage production process. There is an issue with the reproducibility of this process. However, careful selection of the chemical composition of the alloy allows a degree of control over the process. This paper presents the results of investigations into the structure and magnetic properties of rapidly-quenched alloys based on Fe. For these investigations, alloys with the compositions of Fe70Zr8-xCoxNb2B20(where x = 0, 2, 4, 6, or 8) were selected. The alloys were made using an injection-casting method. The structure of the obtained alloys was investigated using X-ray diffractometry. Utilising dedicated software, the crystalline phases within the volume of the samples were identified - as the magnetic phases of Fe23B6, αFe, and Fe2B. The magnetic properties of the produced alloys were determined on the basis of measurements of the magnetic polarisation curves as a function of temperature, and the static hysteresis loops. The thermomagnetic curves confirmed the existence of the Fe23B6phase within the volume of two samples. The values of the saturation magnetisation and coercive field were determined from the static hysteresis loops. The alloys in which the presence of the Fe23B6phase was detected (alloy compositions Fe70Zr4Co4Nb2B20and Fe70Zr2Co6Nb2B20) were found to exhibit soft magnetic properties. A progressive decline in the presence of the Fe2B phase within the investigated alloys was observed with increasing Co content (at the expense of Zr content). On the basis of the performed investigations, the major influence of the Co and Zr content on the creation process of the crystalline phases, during the rapid solidification process was confirmed.

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