Heah Cheng Yong
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Preferred name
Heah Cheng Yong
Official Name
Heah, Cheng Yong
Alternative Name
Yong, Heah Cheng
Yong, H. C.
Heah, Cheng Yong
Heah, C. Y.
Cheng-Yong, Heah
Cheng Yong, Heah
Main Affiliation
Scopus Author ID
54402789500
Researcher ID
S-7139-2019

Research Output

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  • Publication
    Microstructural Analysis of Fly Ash-based Geopolymers with various Alkali Concentration
    ( 2019-08-14)
    Hui-Teng N.
    ;
    Heah Cheng Yong
    ;
    Yun-Ming L.
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Yong-Sing N.
    In the present work, a comparative study on the effect of different concentration of sodium hydroxide (NaOH) on fly ash-based geopolymer was investigated. The geopolymer synthesis by mixing fly ash with alkali activator (a mixture of NaOH and sodium silicate) at solid/liquid ratio of 2.5. The NaOH were used 6M, 8M, 10M, 12M and 14M with constant sodium silicate/NaOH ratio of 2.5. The geopolymers were cured at room temperature (29°C) for 24 hours and 60°C in oven for another 24 hours. The testing and analysis of the fly ash-based geopolymers were performed after 28 days. The adequate Na+ ions and densified microstructure were observed at optimum 8M-NaOH-activated fly ash-based geopolymers.
  • Publication
    Mechanical Properties and Thermal Conductivity of Lightweight Foamed Geopolymer Concretes
    ( 2019-08-14)
    Fatimah Azzahran Abdullah S.
    ;
    Yun-Ming L.
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Heah Cheng Yong
    ;
    Zulkifly K.
    Foamed geopolymer concretes have a better performance in the thermal insulation properties compared to normal geopolymer concretes. In this research, lightweight aggregate geopolymer concretes was incorporated with different percentage of foaming agents (hydrogen peroxide). Compressive strength and thermal conductivity were measured. From results obtained, increased H2O2 contents will decrease the strength of lightweight foamed geopolymer concretes. Lightweight aggregate foamed geopolymer concretes (LWAFGC) with foaming agent content of 0.2wt.% obtained the highest strength of 19.601 MPa. Furthermore, Increased of H2O2 contents also will decrease the thermal conductivity of lightweight foamed geopolymer concretes. Lightweight foamed geopolymer concretes with 2wt.% H2O2 gave the good thermal insulating behavior when the thermal conductivity value recorded the lowest value compare to other wt.% of H2O2 content. The thermal conductivity value of lightweight foamed geopolymer concretes with 2wt.% of H2O2 was 0.072 W/m. K while, the thermal conductivity of other mixtures ranged between 0.077 W/m. K to 0.087 W/m. K., respectively.
  • Publication
    Effect of Solid-to-Liquid Ratio on Thin Fly Ash Geopolymer
    ( 2020-03-18)
    Yong-Sing N.
    ;
    Liew Yun Ming
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Hui-Teng N.
    ;
    Kamarudin Hussin
    ;
    Heah Cheng Yong
    ;
    Nurul Aida Mohd Mortar
    ;
    Sandu A.V.
    The present work studies the effect of solid-to-liquid (S/L) ratio on the properties of thin fly ash-based geopolymer. The fly ash geopolymers with dimension of 160 mm × 40 mm × 10 mm were synthesised by using various S/L ratios (1.5, 2.0, 2.5, 3.0 and 3.2). The alkali activator was prepared by mixing 10M sodium hydroxide (NaOH) solution and sodium silicate (Na2SiO3) with the Na2SiO3/NaOH ratio of 2.5. The samples were cured at 60°C for 6 hours. The performance of fly ash geopolymers was evaluated by testing the flexural strength after 28 days. Results showed that the S/L ratio had an effect on flexural strength. The optimum flexural strength of 5.12 MPa was achieved by the fly ash geopolymer with S/L ratio of 2.5. However, the flexural strength dropped with higher S/L ratio as the workability decreases. However, further experimental lab work should be carried out as there is less knowledge in the study on the flexural strength of thin fly ash geopolymer.
      1  24
  • Publication
    Green development of fly ash geopolymer via casting and pressing Approaches: Strength, Morphology, efflorescence and Ecological Properties
    ( 2023-09-22)
    Shee-Ween O.
    ;
    Heah Cheng Yong
    ;
    Liew Yun Ming
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Ho Li Ngee
    ;
    Pakawanit P.
    ;
    Suhaimi Khalid M.
    ;
    Hazim Bin Wan Muhammad W.
    ;
    Wan-En O.
    ;
    Yong-Jie H.
    ;
    Yong-Sing N.
    ;
    Hui-Teng N.
    The high liquid content of cast geopolymer not only limits its strength development and durability but also leads to high energy consumption and carbon dioxide (CO2) emissions. Thus, a study of the cast and pressed geopolymer was performed. The geopolymers were cured for 1, 7 and 28 d before testing and characterizations. With the incorporation of pressure compaction, higher bulk density (2158–2227 kg/m3) was recorded for pressed geopolymer in comparison to cast geopolymer (1842–1854 kg/m3). The dense matrix in pressed geopolymer improved the inter-particle contact, increasing the 28 d degree of reaction to 39.7%, higher than that of cast geopolymer (33.0%). This feature was proved by SEM micrographs wherein the pressed geopolymer was well-compacted and denser in microstructure, with less unreacted/partially reacted fly ash and pores. The compressive and flexural strengths of pressed geopolymer reached 114.2 and 29.9 MPa after 28 d, higher than that of cast geopolymer (60.0 and 6.2 MPa, respectively). The strength reduction of pressed geopolymer (31.7%) after the accelerated efflorescence test was lower than that of cast geopolymer (60.2%). The ecological analysis inferred that pressed geopolymer was ecologically superior to the casting method in terms of embodied energy (EE) and embodied carbon dioxide emission (ECO2), in which 50% and 59% of reductions are acquired. Besides, the embodied carbon index (ECI) of pressed geopolymer was about 21% of cast geopolymer.
      1  17
  • Publication
    Comparative efficiency study of photoanodes in the photocatalytic fuel cell integrated electro-Fenton hybrid system
    ( 2023-01-01)
    Thor S.H.
    ;
    Ho Li Ngee
    ;
    Ong Soon An
    ;
    Che Zulzikrami Azner Abidin
    ;
    Heah Cheng Yong
    Photoanode in photocatalytic fuel cell (PFC) plays an important role in the dual chamber PFC integrating electro-Fenton (EF) hybrid system (PFC-EF system) since the photo-excitation process on the photoanode will contribute to the electrons for electricity generation and electro-generation of hydrogen peroxide in EF process. Fabrication of different types of photoanodes were carried out by using anodizing and immobilization method, respectively. The fabrication methods significantly affected the efficiencies of photoanodes in the Amaranth treatment. The characterization of the fabricated photoanodes was carried out by X-ray diffraction and scanning electron microscopy. The immobilized ZnO/Zn photoanode achieved the highest degradation efficiencies in both PFC (80.36%) and EF (86.88%). The immobilized ZnO/Zn photoanode also contributed to the highest power density (4.545 μW cm-2).
      1
  • Publication
    Properties of polyaniline/graphene oxide (PANI/GO) composites: effect of GO loading
    ( 2021-09-01)
    Mutalib T.N.A.B.T.A.
    ;
    Tan Soo Jin
    ;
    Foo Kai Loong
    ;
    Liew Yun Ming
    ;
    Heah Cheng Yong
    ;
    Mohd. Mustafa Al Bakri Abdullah
    Polyaniline/graphene oxide (PANI/GO) composites at different wt% of GO were prepared via solution method. PANI was mixed with the GO synthesized from the improved Hummer’s method. The formation of GO was confirmed via Raman and C/O ratio. Based on the FT-IR, XRD and SEM results, it confirmed the presence of both PANI and GO characteristics at 10.9°, 25.8° and 27.8° and interactions between PANI and GO particles in PANI/GO composites at different GO loading. SEM micrographs showed a folding and wrinkled surface of GO due to the defect upon oxidation process. This means that the weak π–π interactions or the agglomeration of GO have caused PANI unable to attach on the large conjugated basal planes of GO sheets. The defective domains made GO as an insulator as it contained distortions and oxygen-containing functional groups and their local decoration. Low-conductivity domain had conquered most of the GO region which later reduced the pathway of the current flow; therefore, conductivity is affected. The wrinkled structure also resulted in the low conductivity as it weakens the interfacial interaction between PANI and GO and thus disrupted the electron movement in the composites. Due to this, the electrical conductivity reached up to 1.83 × 10−10 S/cm as the GO loading increased to 50 wt%.
      2
  • Publication
    Cold-pressed fly ash geopolymers: effect of formulation on mechanical and morphological characteristics
    ( 2021)
    Ong Shee-Ween
    ;
    Heah Cheng Yong
    ;
    Lynette Wei Ling Chan
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Ho Li Ngee
    ;
    Liew Yun Ming
    ;
    Ooi Wan-En
    ;
    Ng Yong-Sing
    ;
    Nur Ain Jaya
    This research uses low alkali activator content and cold pressing technique for fly ash-based geopolymers formation under room temperature condition. The geopolymers were prepared using four different parameters: fly ash/alkali activator ratio, sodium hydroxide concentration, sodium silicate/sodium hydroxide ratio and pressing force. The results indicated that the compressive strength (114.2 MPa) and flexural strength (29.9 MPa) of geopolymers maximised at a fly ash/alkali activator ratio of 5.5, a 14 M sodium hydroxide concentration, a sodium silicate/sodium hydroxide ratio of 1.5 and a pressing force of 5 tons (pressing stress of 100.0 MPa and 155.7 MPa for compressive and flexural samples, respectively). The degree of reaction (40.1%) enhanced the structure compactness with minimum porosity. The improved mechanical properties confirmed that a high strength pressed geopolymer could be formed at low alkali activator content without the aid of temperature.
      1  35
  • Publication
    Effect of sodium aluminate on the fresh and hardened properties of fly ash-based one-part geopolymer
    ( 2021)
    Ooi Wan-En
    ;
    Liew Yun Ming
    ;
    Heah Cheng Yong
    ;
    Ho Li Ngee
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Ong Shee-Ween
    ;
    Andrei Victor Sandu
    The one-part geopolymer binder was synthesis from the mixing of aluminosilicate material with solid alkali activators. The properties of one-part geopolymers vary according to the type and amount of solid alkali activators used. This paper presents the effect of various sodium metasilicate-to-sodium aluminate (NaAlO2/Na2SiO3) ratios on fly ash-based one-part geopolymer. The NaAlO2/Na2SiO3 ratios were set at 1.0 to 3.0. Setting time of fresh one-part geopolymer was examined through Vicat needle apparatus. Mechanical and microstructural properties of developed specimens were analysed after 28 days of curing in ambient condition. The study concluded that an increase in NaAlO2 content delayed the setting time of one-part geopolymer paste. The highest compressive strength was achieved at the NaAlO2/Na2SiO3 ratio of 2.5, which was 33.65 MPa. The microstructural analysis revealed a homogeneous structure at the optimum ratio. While the sodium aluminium silicate hydrate (N-A-S-H) and anorthite phases were detected from the XRD analysis.
      7  15
  • Publication
    Functionalized Carbon Nanotube-Modified ELISA for Early Detection of Heart Attack
    ( 2023-12-01)
    Chow E.M.Y.
    ;
    Foo Kai Loong
    ;
    Subash Chandra Bose Gopinath
    ;
    Tan Soo Jin
    ;
    Kashif M.
    ;
    Heah Cheng Yong
    ;
    Liew Yun Ming
    A warning issue of heart attacks in young adults needs immediate attention lately. Enzyme-linked immunosorbent assay (ELISA) is an easy and commonly used method for detecting early stages of heart attack. Cardiac troponin I (cTnI) is a responsible biomarker for acute myocardial infarction. However, the conventional ELISA system was only able to detect at 100 pM of cTnI. To improve the system, enhancements were introduced through the integration of functionalized carbon nanotube (fCNT) to amplify cTnI detection signals. By utilizing the advantage of fCNT, a noticeable improvement in results can be obtained. The detection limit was lowered down to an impressive 10 pM. Furthermore, the change of absorbance increased from 31.90% for conventional ELISA surge to 98.61 for modified ELISA system. This three-fold increase in sensitivity shows remarkable improvement through the introduction of fCNT in modified ELISA technique.
      1
  • Publication
    Microwave-absorbing building materials: Assessing thickness and antenna separation in fly ash-ladle furnace slag one-part geopolymer
    ( 2024-06-15)
    Yong-Jie H.
    ;
    Heah Cheng Yong
    ;
    Liew Yun Ming
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Yeng-Seng L.
    ;
    Wei-Hao L.
    ;
    Pakawanit P.
    ;
    Ern-Hun K.
    ;
    Shee-Ween O.
    This paper aims to examine the effect of thickness (20, 40, 60, 80, and 100 mm) and antenna separation (20, 40, 60, 80, and 100 mm) on microwave absorption ability of fly ash-ladle furnace slag one-part geopolymer. The one-part geopolymers exhibited a dense structure with a good compressive strength of 39.2 MPa, which satisfies the minimum requirement for structural building (>28.0 MPa). The geopolymers had good dielectric properties with a low dielectric constant and increased dielectric loss and loss tangent, subsequently contributing to the microwave absorption properties. The microwave absorption ability increased from 60.0% to >80.0% at an optimal thickness of 100.0 mm and antenna separation of 20.0 mm. The presence of calcium-silicate-hydrate (C–S–H) refined the microstructure and enhanced the microwave absorption performance. This work offered an optimal thickness and antenna separation to maximize the microwave absorption ability, which is crucial for reducing microwave interference and preventing public exposure in regions with widespread deployment of Wi-Fi and 5G networks.
      1  27