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 - 10 of 16
  • Publication
    Effect of NaOH molar concentration on microstructure and compressive strength of Dolomite/Fly Ash-Based geopolymers
    ( 2021)
    Emy Aizat Azimi
    ;
    M.A.A. Mohd Salleh
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Ikmal Hakem A. Aziz
    ;
    Kamarudin Hussin
    ;
    Jitrin Chaiprapa
    ;
    Petrica Vizureanu
    ;
    Sorachon Yoriya
    ;
    Marcin Nabiałek
    ;
    Jerzy J. Wyslocki
    Dolomite can be used as a source of aluminosilicate to produce geopolymers; however, this approach is limited by its low reactivity. This study analyzes the viability of producing geopolymers using dolomite/fly-ash with sodium silicate and NaOH solutions (at multiple concentrations) by determining the resultant geopolymers’ compressive strengths. The dolomite/fly-ash-based geopolymers at a NaOH concentration of ~22 M resulted in an optimum compressive strength of 46.38 MPa after being cured for 28 days, and the SEM and FTIR analyses confirmed the denser surface of the geopolymer matrix. The synchrotron micro-XRF analyses confirmed that the Ca concentration exceeded that of Si and Mg, leading to the formation of calcium silicate hydrate, which strengthens the resulting geopolymers.
  • Publication
    Microstructure and porosity evolution of alkali activated slag at various heating temperatures
    ( 2020)
    Ikmal Hakem Aziz
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    M.A.A. Mohd Salleh
    ;
    Sorachon Yoriya
    ;
    Jitrin Chaiprapa
    ;
    Catleya Rojviriya
    ;
    Long Yuan Li
    This paper elucidated the microstructural and porosity evolution of alkali activated slag at 800 °C up to 1200 °C. The microstructural analysis obtained shows the changes in surface densification of glassy phase and nucleation of dynamical grains within the alkali activated slag when in contact with high heating temperature. Using synchrotron radiation X-ray tomographic microscopy, the number of pores in alkali activated slag decreased with increasing heating temperature. The 3D pores distribution also demonstrated significant increase in the range size of ~20 μm with the appearance of isolated and intergranular pores at 1200 °C. These changes also led to the anorthite crystallisation indicated by high angle grain boundaries and preferred crystal orientation. The evolution of porosity and crystalline phase is contributed to the development of internal strain after heating at high temperature environment.
  • Publication
    Role of sintering temperature in production of nepheline Ceramics-Based geopolymer with addition of ultra-high molecular weight polyethylene
    ( 2021)
    Romisuhani Ahmad
    ;
    Fakhryna Hannanee Ahmad Zaidi
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Wan Mastura Wan Ibrahim
    ;
    Jitrin Chaiprapa
    ;
    Kamarudin Hussin
    ;
    Jerzy J. Wysłocki
    ;
    Katarzyna BÅ‚och
    ;
    Marcin Nabiałek
    The primary motivation of developing ceramic materials using geopolymer method is to minimize the reliance on high sintering temperatures. The ultra-high molecular weight polyethylene (UHMWPE) was added as binder and reinforces the nepheline ceramics based geopolymer. The samples were sintered at 900 °C, 1000 °C, 1100 °C, and 1200 °C to elucidate the influence of sintering on the physical and microstructural properties. The results indicated that a maximum flexural strength of 92 MPa is attainable once the samples are used to be sintered at 1200 °C. It was also determined that the density, porosity, volumetric shrinkage, and water absorption of the samples also affected by the sintering due to the change of microstructure and crystallinity. The IR spectra reveal that the band at around 1400 cm−1 becomes weak, indicating that sodium carbonate decomposed and began to react with the silica and alumina released from gels to form nepheline phases. The sintering process influence in the development of the final microstructure thus improving the properties of the ceramic materials.
      8  10
  • Publication
    Strength development and elemental distribution of Dolomite/Fly Ash geopolymer composite under elevated temperature
    ( 2020)
    Emy Aizat Azimi
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Petrica Vizureanu
    ;
    Mohd Arif Anuar Mohd Salleh
    ;
    Jitrin Chaiprapa
    ;
    Sorachon Yoriya
    ;
    Andrei Victor Sandu
    ;
    Kamarudin Hussin
    ;
    Ikmal Hakem Aziz
    A geopolymer has been reckoned as a rising technology with huge potential for application across the globe. Dolomite refers to a material that can be used raw in producing geopolymers. Nevertheless, dolomite has slow strength development due to its low reactivity as a geopolymer. In this study, dolomite/fly ash (DFA) geopolymer composites were produced with dolomite, fly ash, sodium hydroxide, and liquid sodium silicate. A compression test was carried out on DFA geopolymers to determine the strength of the composite, while a synchrotron Micro-Xray Fluorescence (Micro-XRF) test was performed to assess the elemental distribution in the geopolymer composite. The temperature applied in this study generated promising properties of DFA geopolymers, especially in strength, which displayed increments up to 74.48 MPa as the optimum value. Heat seemed to enhance the strength development of DFA geopolymer composites. The elemental distribution analysis revealed exceptional outcomes for the composites, particularly exposure up to 400 °C, which signified the homogeneity of the DFA composites. Temperatures exceeding 400 °C accelerated the strength development, thus increasing the strength of the DFA composites. This appears to be unique because the strength of ordinary Portland Cement (OPC) and other geopolymers composed of other raw materials is typically either maintained or decreases due to increased heat.
      4  14
  • Publication
    Role of sintering temperature in production of nepheline ceramics-based geopolymer with addition of ultra-high molecular weight polyethylene
    (MDPI, 2021)
    Romisuhani Ahmad
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Jitrin Chaiprapa
    ;
    Kamarudin Hussin
    ;
    Wan Mastura Wan Ibrahim
    ;
    Fakhryna Hannanee Ahmad Zaidi
    ;
    Jerzy J. Wysłocki
    ;
    Katarzyna BÅ‚och
    ;
    Marcin Nabiałek
    The primary motivation of developing ceramic materials using geopolymer method is to minimize the reliance on high sintering temperatures. The ultra-high molecular weight polyethylene (UHMWPE) was added as binder and reinforces the nepheline ceramics based geopolymer. The samples were sintered at 900 °C, 1000 °C, 1100 °C, and 1200 °C to elucidate the influence of sintering on the physical and microstructural properties. The results indicated that a maximum flexural strength of 92 MPa is attainable once the samples are used to be sintered at 1200 °C. It was also determined that the density, porosity, volumetric shrinkage, and water absorption of the samples also affected by the sintering due to the change of microstructure and crystallinity. The IR spectra reveal that the band at around 1400 cm−1 becomes weak, indicating that sodium carbonate decomposed and began to react with the silica and alumina released from gels to form nepheline phases. The sintering process influence in the development of the final microstructure thus improving the properties of the ceramic materials.
      3  19
  • Publication
    Mechanical performance, microstructure, and porosity evolution of fly ash geopolymer after ten years of curing age
    ( 2023)
    Ikmal Hakem A. Aziz
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Rafiza Abd Razak
    ;
    Zarina Yahya
    ;
    Mohd Arif Anuar Mohd Salleh
    ;
    Jitrin Chaiprapa
    ;
    Catleya Rojviriya
    ;
    Petrica Vizureanu
    ;
    Andrei Victor Sandu
    ;
    Muhammad Faheem Mohd. Tahir
    ;
    Alida Abdullah
    ;
    Liyana Jamaludin
    This paper elucidates the mechanical performance, microstructure, and porosity evolution of fly ash geopolymer after 10 years of curing age. Given their wide range of applications, understanding the microstructure of geopolymers is critical for their long-term use. The outcome of fly ash geopolymer on mechanical performance and microstructural characteristics was compared between 28 days of curing (FA28D) and after 10 years of curing age (FA10Y) at similar mixing designs. The results of this work reveal that the FA10Y has a beneficial effect on strength development and denser microstructure compared to FA28D. The total porosity of FA10Y was also lower than FA28D due to the anorthite formation resulting in the compacted matrix. After 10 years of curing age, the 3D pore distribution showed a considerable decrease in the range of 5–30 µm with the formation of isolated and intergranular holes.
      20  1
  • Publication
    Metakaolin/sludge based geopolymer adsorbent on high removal efficiency of Cu2+
    ( 2022)
    Pilomeena Arokiasamy
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Shayfull Zamree Abd. Rahim
    ;
    Mohd Remy Rozainy Mohd Arif Zainol
    ;
    Mohd Arif Anuar Mohd Salleh
    ;
    Marwan Kheimi
    ;
    Jitrin Chaiprapa
    ;
    Andrei Victor Sandu
    ;
    Petrica Vizureanu
    ;
    Rafiza Abd Razak
    ;
    Noorina Hidayu Jamil
    Activated carbon (AC) has received a lot of interest from researchers for the removal of heavy metals from wastewater due to its abundant porous structure. However, it was found unable to meet the required adsorption capacity due to its amorphous structure which restricts the fundamental studies and structural optimization for improved removal performance. In addition, AC is not applicable in large scale wastewater treatment due its expensive synthesis and difficulty in regeneration. Thus, the researchers are paying more attention in synthesis of low cost geopolymer based adsorbent for heavy metal removal due its excellent immobilization effect. However, limited studies have focused on the synthesis of geopolymer based adsorbent for heavy metal adsorption by utilizing industrial sludge. Thus, the aim of this research was to develop metakaolin (MK) based geopolymer adsorbent with incorporation of two types of industrial sludge (S1 and S3) that could be employed as an adsorbent for removing copper (Cu2+) from aqueous solution through the adsorption process. The effects of varied solid to liquid ratio (S/L) on the synthesis of metakaolin/sludge based geopolymer adsorbent and the removal efficiency of Cu2+ by the synthesis adsorbent were studied. The raw materials and synthesized geopolymer were characterized by using x-ray fluorescence (XRF), x-ray diffraction (XRD), scanning electron microscope (SEM), fourier transform infrared spectroscopy (FTIR), Brunauer-Emmett-Teller (BET) and micro XRF. The concentration of Cu2+ before and after adsorption was determined by atomic absorption spectroscopy (AAS) and the removal efficiency was calculated. The experimental data indicated that the synthesized geopolymer at low S/L ratio has achieved the highest removal efficiency of Cu2+ about 99.62 % and 99.37 % at 25 %:75 % of MK/S1 and 25 %:75 % of MK/S3 respectively compared to pure MK based geopolymer with 98.56 %. The best S/
      1  28
  • Publication
    Strength development and elemental distribution of Dolomite/Fly Ash geopolymer composite under elevated temperature
    ( 2020)
    Emy Aizat Azimi
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Petrica Vizureanu
    ;
    Mohd Arif Anuar Mohd Salleh
    ;
    Andrei Victor Sandu
    ;
    Jitrin Chaiprapa
    ;
    Sorachon Yoriya
    ;
    Kamarudin Hussin
    ;
    Ikmal Hakem Aziz
    A geopolymer has been reckoned as a rising technology with huge potential for application across the globe. Dolomite refers to a material that can be used raw in producing geopolymers. Nevertheless, dolomite has slow strength development due to its low reactivity as a geopolymer. In this study, dolomite/fly ash (DFA) geopolymer composites were produced with dolomite, fly ash, sodium hydroxide, and liquid sodium silicate. A compression test was carried out on DFA geopolymers to determine the strength of the composite, while a synchrotron Micro-Xray Fluorescence (Micro-XRF) test was performed to assess the elemental distribution in the geopolymer composite. The temperature applied in this study generated promising properties of DFA geopolymers, especially in strength, which displayed increments up to 74.48 MPa as the optimum value. Heat seemed to enhance the strength development of DFA geopolymer composites. The elemental distribution analysis revealed exceptional outcomes for the composites, particularly exposure up to 400 °C, which signified the homogeneity of the DFA composites. Temperatures exceeding 400 °C accelerated the strength development, thus increasing the strength of the DFA composites. This appears to be unique because the strength of ordinary Portland Cement (OPC) and other geopolymers composed of other raw materials is typically either maintained or decreases due to increased heat.
      7  23
  • Publication
    The influence of sintering temperature on the pore structure of an Alkali-Activated Kaolin-Based Geopolymer Ceramic
    ( 2022)
    Mohd Izrul Izwan Ramli
    ;
    Mohd Arif Anuar Mohd Salleh
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Ikmal Hakem Aziz
    ;
    Tan Chi Ying
    ;
    Noor Fifinatasha Shahedan
    ;
    Winfried Kockelmann
    ;
    Anna Fedrigo
    ;
    Andrei Victor Sandu
    ;
    Petrica Vizureanu
    ;
    Jitrin Chaiprapa
    ;
    Dumitru Doru Burduhos Nergis
    Geopolymer materials are used as construction materials due to their lower carbon dioxide (CO2) emissions compared with conventional cementitious materials. An example of a geopolymer material is alkali-activated kaolin, which is a viable alternative for producing high-strength ceramics. Producing high-performing kaolin ceramics using the conventional method requires a high processing temperature (over 1200 °C). However, properties such as pore size and distribution are affected at high sintering temperatures. Therefore, knowledge regarding the sintering process and related pore structures on alkali-activated kaolin geopolymer ceramic is crucial for optimizing the properties of the aforementioned materials. Pore size was analyzed using neutron tomography, while pore distribution was observed using synchrotron micro-XRF. This study elucidated the pore structure of alkali-activated kaolin at various sintering temperatures. The experiments showed the presence of open pores and closed pores in alkali-activated kaolin geopolymer ceramic samples. The distributions of the main elements within the geopolymer ceramic edifice were found with Si and Al maps, allowing for the identification of the kaolin geopolymer. The results also confirmed that increasing the sintering temperature to 1100 °C resulted in the alkali-activated kaolin geopolymer ceramic samples having large pores, with an average size of ~80 µm3 and a layered porosity distribution.
      1  24
  • Publication
    Influence of sintering temperature of kaolin, slag, and fly ash geopolymers on the microstructure, phase analysis, and electrical conductivity
    ( 2021)
    Nur Nadiah Izzati Zulkifli
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Anna Przybył
    ;
    Paweł Pietrusiewicz
    ;
    Mohd Arif Anuar Mohd Salleh
    ;
    Ikmal Hakem Aziz
    ;
    Dariusz Kwiatkowski
    ;
    Marcin Gacek
    ;
    Marek Gucwa
    ;
    Jitrin Chaiprapa
    This paper clarified the microstructural element distribution and electrical conductivity changes of kaolin, fly ash, and slag geopolymer at 900 °C. The surface microstructure analysis showed the development in surface densification within the geopolymer when in contact with sintering temperature. It was found that the electrical conductivity was majorly influenced by the existence of the crystalline phase within the geopolymer sample. The highest electrical conductivity (8.3 × 10−4 Ωm−1) was delivered by slag geopolymer due to the crystalline mineral of gehlenite (3Ca2Al2SiO7). Using synchrotron radiation X-ray fluorescence, the high concentration Ca boundaries revealed the appearance of gehlenite crystallisation, which was believed to contribute to development of denser microstructure and electrical conductivity.
      1  17