Now showing 1 - 10 of 19
  • Publication
    Preparation of Fly Ash-Ladle Furnace Slag Blended Geopolymer Foam via Pre-Foaming Method with Polyoxyethylene Alkyether Sulphate Incorporation
    ( 2022-06-01)
    Ng Hui Teng
    ;
    ; ; ;
    Rojviriya C.
    ;
    Razi H.M.
    ;
    Garus S.
    ;
    Nabiałek M.
    ;
    Sochacki W.
    ;
    Abidin I.M.Z.
    ;
    Ng Yong Sing
    ;
    Śliwa A.
    ;
    Sandu A.V.
    This paper uses polyoxyethylene alkyether sulphate (PAS) to form foam via pre-foaming method, which is then incorporated into geopolymer based on fly ash and ladle furnace slag. In the literature, only PAS-geopolymer foams made with single precursor were studied. Therefore, the performance of fly ash-slag blended geopolymer with and without PAS foam was investigated at 29–1000 °C. Unfoamed geopolymer (G-0) was prepared by a combination of sodium alkali, fly ash and slag. The PAS foam-to-paste ratio was set at 1.0 and 2.0 to prepare geopolymer foam (G-1 and G-2). Foamed geopolymer showed decreased compressive strength (25.1–32.0 MPa for G-1 and 21.5–36.2 MPa for G-2) compared to G-0 (36.9–43.1 MPa) at 29–1000 °C. Nevertheless, when compared to unheated samples, heated G-0 lost compressive strength by 8.7% up to 1000 °C, while the foamed geopolymer gained compressive strength by 68.5% up to 1000 °C. The thermal stability of foamed geopolymer was greatly improved due to the increased porosity, lower thermal conductivity, and incompact microstructure, which helped to reduce pressure during moisture evaporation and resulted in lessened deterioration.
      1
  • Publication
    Near-Infrared (NIR) Silver Sulfide (Ag₂S) Semiconductor Photocatalyst Film for Degradation of Methylene Blue Solution
    ( 2023-01-01)
    Mubarokah Z.R.
    ;
    ; ; ; ;
    Błoch K.
    ;
    Nabiałek M.
    ;
    Baltatu M.S.
    ;
    Sandu A.V.
    ;
    Vizureanu P.
    A silver sulfide (Ag2S) semiconductor photocatalyst film has been successfully synthesized using a solution casting method. To produce the photocatalyst films, two types of Ag2S powder were used: a commercialized and synthesized powder. For the commercialized powder (CF/comAg2S), the Ag2S underwent a rarefaction process to reduce its crystallite size from 52 nm to 10 nm, followed by incorporation into microcrystalline cellulose using a solution casting method under the presence of an alkaline/urea solution. A similar process was applied to the synthesized Ag2S powder (CF/syntAg2S), resulting from the co-precipitation process of silver nitrate (AgNO3) and thiourea. The prepared photocatalyst films and their photocatalytic efficiency were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and UV-visible spectroscopy (UV-Vis). The results showed that the incorporation of the Ag2S powder into the cellulose films could reduce the peak intensity of the oxygen-containing functional group, which indicated the formation of a composite film. The study of the crystal structure confirmed that all of the as-prepared samples featured a monoclinic acanthite Ag2S structure with space group P21/C. It was found that the degradation rate of the methylene blue dye reached 100% within 2 h under sunlight exposure when using CF/comAg2S and 98.6% for the CF/syntAg2S photocatalyst film, and only 48.1% for the bare Ag2S powder. For the non-exposure sunlight samples, the degradation rate of only 33–35% indicated the importance of the semiconductor near-infrared (NIR) Ag2S photocatalyst used.
      2
  • Publication
    Improvements of Flexural Properties and Thermal Performance in Thin Geopolymer Based on Fly Ash and Ladle Furnace Slag Using Borax Decahydrates
    ( 2022-06-01)
    Ng Yong-Sing
    ;
    ; ; ;
    Pakawanit P.
    ;
    Vizureanu P.
    ;
    Khalid M.S.
    ;
    Ng Hui-Teng
    ;
    Hanh Yong-Jie
    ;
    Nabiałek M.
    ;
    Pietrusiewicz P.
    ;
    Garus S.
    ;
    Sochacki W.
    ;
    Śliwa A.
    This paper elucidates the influence of borax decahydrate addition on the flexural and thermal properties of 10 mm thin fly ash/ladle furnace slag (FAS) geopolymers. The borax decahydrate (2, 4, 6, and 8 wt.%) was incorporated to produce FAB geopolymers. Heat treatment was applied with temperature ranges of 300◦C, 600◦C, 900◦C, 1000◦C and 1100◦C. Unexposed FAB geopolymers experienced a drop in strength due to a looser matrix with higher porosity. However, borax decahydrate inclusion significantly enhanced the flexural performance of thin geopolymers after heating. FAB2 and FAB8 geopolymers reported higher flexural strength of 26.5 MPa and 47.8 MPa, respectively, at 1000◦C as compared to FAS geopolymers (24.1 MPa at 1100◦C). The molten B2O3 provided an adhesive medium to assemble the aluminosilicates, improving the interparticle connectivity which led to a drastic strength increment. Moreover, the borax addition reduced the glass transition temperature, forming more refractory crystalline phases at lower temperatures. This induced a significant strength increment in FAB geopolymers with a factor of 3.6 for FAB8 at 900◦C, and 4.0 factor for FAB2 at 1000◦C, respectively. Comparatively, FAS geopolymers only achieved 3.1 factor in strength increment at 1100◦C. This proved that borax decahydrate could be utilized in the high strength development of thin geopolymers.
      1
  • Publication
    Improvements of Flexural Properties and Thermal Performance in Thin Geopolymer Based on Fly Ash and Ladle Furnace Slag Using Borax Decahydrates
    ( 2022-06-01)
    Ng Yong-Sing
    ;
    ; ; ;
    Pakawanit P.
    ;
    Vizureanu P.
    ;
    Khalid M.S.
    ;
    Ng Hui-Teng
    ;
    Yong-Jie H.
    ;
    Nabiałek M.
    ;
    Pietrusiewicz P.
    ;
    Garus S.
    ;
    Sochacki W.
    ;
    Śliwa A.
    This paper elucidates the influence of borax decahydrate addition on the flexural and thermal properties of 10 mm thin fly ash/ladle furnace slag (FAS) geopolymers. The borax decahydrate (2, 4, 6, and 8 wt.%) was incorporated to produce FAB geopolymers. Heat treatment was applied with temperature ranges of 300◦C, 600◦C, 900◦C, 1000◦C and 1100◦C. Unexposed FAB geopolymers experienced a drop in strength due to a looser matrix with higher porosity. However, borax decahydrate inclusion significantly enhanced the flexural performance of thin geopolymers after heating. FAB2 and FAB8 geopolymers reported higher flexural strength of 26.5 MPa and 47.8 MPa, respectively, at 1000◦C as compared to FAS geopolymers (24.1 MPa at 1100◦C). The molten B2O3 provided an adhesive medium to assemble the aluminosilicates, improving the interparticle connectivity which led to a drastic strength increment. Moreover, the borax addition reduced the glass transition temperature, forming more refractory crystalline phases at lower temperatures. This induced a significant strength increment in FAB geopolymers with a factor of 3.6 for FAB8 at 900◦C, and 4.0 factor for FAB2 at 1000◦C, respectively. Comparatively, FAS geopolymers only achieved 3.1 factor in strength increment at 1100◦C. This proved that borax decahydrate could be utilized in the high strength development of thin geopolymers.
      1
  • Publication
    Optimisation of shrinkage and strength on thick plate part using recycled ldpe materials
    ( 2021-04-01)
    Roslan N.
    ;
    ;
    Abdellah A.E.H.
    ;
    ;
    Błoch K.
    ;
    Pietrusiewicz P.
    ;
    Nabiałek M.
    ;
    Szmidla J.
    ;
    Kwiatkowski D.
    ;
    Vasco J.O.C.
    ;
    ;
    Achieving good quality of products from plastic injection moulding processes is very challenging, since the process comprises many affecting parameters. Common defects such as warpage are hard to avoid, and the defective parts will eventually go to waste, leading to unnecessary costs to the manufacturer. The use of recycled material from postindustrial waste has been studied by a few researchers. However, the application of an optimisation method by which to optimise processing parameters to mould parts using recycled materials remains lacking. In this study, Response Surface Methodology (RSM) and Particle Swarm Optimisation (PSO) methods were conducted on thick plate parts moulded using virgin and recycled low-density polyethylene (LDPE) materials (100:0, 70:30, 60:40 and 50:50; virgin to recycle material ratios) to find the optimal input parameters for each of the material ratios. Shrinkage in the x and y directions increased in correlation with the recycled ratio, compared to virgin material. Meanwhile, the tensile strength of the thick plate part continued to decrease when the recycled ratio increased. R30 (70:30) had the optimum shrinkage in the x direction with respect to R0 (100:0) material where the shrinkage increased by 24.49% (RSM) and 33.20% (PSO). On the other hand, the shrinkage in the y direction for R30 material increased by 4.48% (RSM) and decreased by 2.67% (PSO), while the tensile strength of R30 (70:30) material decreased by 0.51% (RSM) and 2.68% (PSO) as compared to R0 (100:0) material. Validation tests indicated that the optimal setting of processing parameter suggested by PSO and RSM for R0 (100:0), R30 (70:30), R40 (60:40) and R50 (50:50) was less than 10%.
      2
  • Publication
    INFLUENCE OF SALINITY OF MIXING WATER TOWARDS PHYSICAL AND MECHANICAL PROPERTIES OF HIGH STRENGTH CONCRETE
    ( 2023-01-01) ;
    Yen Ng K.
    ;
    ; ;
    Mohamed R.
    ;
    Muthusamy K.
    ;
    Jusoh W.A.W.
    ;
    Nabiałek M.
    ;
    Jeż B.
    Dramatic population and economic growth result in increasing demand for concrete infrastructure, which leads to an increment of freshwater demand and a reduction of freshwater resources. However, freshwater is a finite resource, which means that freshwater will be used up someday in the future when freshwater demand keeps increasing while freshwater resources are limited. Therefore, replacing freshwater with seawater in concrete blending seems potentially beneficial for maintaining the freshwater resources as well as advantageous alternatives to the construction work near the sea. There have been few experimental research on the effect of blending water salt content on the mechanical and physical characteristics of concrete, particularly high-strength concrete. Therefore, a research study on the influence of salt concentration of blending water on the physical and mechanical properties of high-strength concrete is necessary. This study covered the blending water salinity, which varied from 17.5 g/L to 52.5 g/L and was determined on the physical and mechanical properties, including workability, density, compressive strength, and flexural strength. The test results indicate that the use of sea salt in blending water had a slight negative influence on both the workability and the density of high strength concrete. It also indicates that the use of sea salt in blending water had a positive influence on both the compressive strength and the flexural strength of high-strength concrete in an earlystage.
      1  21
  • Publication
    Phase transformation of Kaolin-ground granulated blast furnace slag from geopolymerization to sintering process
    ( 2021-03-01) ; ; ;
    Hasmaliza M.
    ;
    ;
    Aziz I.H.A.
    ;
    Jeż B.
    ;
    Nabiałek M.
    The main objective of this research was to investigate the influence of curing temperature on the phase transformation, mechanical properties, and microstructure of the as-cured and sintered kaolin-ground granulated blast furnace slag (GGBS) geopolymer. The curing temperature was varied, giving four different conditions; namely: Room temperature, 40, 60, and 80◦ C. The kaolin-GGBS geopolymer was prepared, with a mixture of NaOH (8 M) and sodium silicate. The samples were cured for 14 days and sintered afterwards using the same sintering profile for all of the samples. The sintered kaolin-GGBS geopolymer that underwent the curing process at the temperature of 60◦ C featured the highest strength value: 8.90 MPa, and a densified microstructure, compared with the other samples. The contribution of the Na2 O in the geopolymerization process was as a self-fluxing agent for the production of the geopolymer ceramic at low temperatures.
      2
  • Publication
    The effect of polyethylene glycol addition on wettability and optical properties of go/tio2 thin film
    ( 2021-08-02) ; ; ; ;
    Nabiałek M.
    ;
    Ramli M.M.
    ;
    Razak M.F.S.A.
    ;
    Sandu A.V.
    ;
    Sochacki W.
    ;
    Skrzypczak T.
    Modification has been made to TiO2 thin film to improve the wettability and the absorption of light. The sol‐gel spin coating method was successfully used to synthesize GO/TiO2 thin films using a titanium (IV) isopropoxide (TTIP) as a precursor. Different amounts of polyethylene glycol (PEG) (20 to 100 mg) were added into the parent sol solution to improve the optical properties and wettability of the GO/TiO2 thin film. The effect of different amounts of PEG was characterized using X‐ray diffraction (XRD) for the phase composition, scanning electron microscopy (SEM) for micro-structure observation, atomic force microscopy (AFM) for the surface topography, ultraviolet–visi-ble spectrophotometry (UV‐VIS) for the optical properties and wettability of the thin films by meas-uring the water contact angle. The XRD analysis showed the amorphous phase. The SEM and AFM images revealed that the particles were less agglomerated and surface roughness increases from 1.21 × 102 to 2.63 × 102 nm when the amount of PEG increased. The wettability analysis results show that the water contact angle of the thin film decreased to 27.52° with the increase of PEG to 80 mg which indicated that the thin film has hydrophilic properties. The optical properties also improved significantly, where the light absorbance wavelength became wider and the band gap was reduced from 3.31 to 2.82 eV with the presence of PEG.
      3
  • Publication
    Warpage optimisation using recycled polycar-bonates (PC) on front panel housing
    ( 2021-03-02)
    Tamizi N.A.M.A.
    ;
    ;
    Abdellah A.E.H.
    ;
    ;
    Nabiałek M.
    ;
    Wysłocki J.J.
    ;
    Jeż B.
    ;
    Palutkiewicz P.
    ;
    ; ;
    Many studies have been done using recycled waste materials to minimise environmental problems. It is a great opportunity to explore mechanical recycling and the use of recycled and virgin blend as a material to produce new products with minimum defects. In this study, appropriate processing parameters were considered to mould the front panel housing part using R0% (virgin), R30% (30% virgin: 70% recycled), R40% (40% virgin: 60% recycled) and R50% (50% virgin: 50% recycled) of Polycarbonate (PC). The manufacturing ability and quality during preliminary stage can be predicted through simulation analysis using Autodesk Moldflow Insight 2012 software. The recommended processing parameters and values of warpage in x and y directions can also be obtained using this software. No value of warpage was obtained from simulation studies for x direction on the front panel housing. Therefore, this study only focused on reducing the warpage in the y direction. Response Surface Methodology (RSM) and Genetic Algorithm (GA) optimisation methods were used to find the optimal processing parameters. As the results, the optimal ratio of recycled PC material was found to be R30%, followed by R40% and R50% materials using RSM and GA methods as compared to the average value of warpage on the moulded part using R0%. The most influential processing parameter that contributed to warpage defect was packing pressure for all materials used in this study.
      1  29
  • Publication
    Characterization of SnO₂/TiO₂ With The Addition of Polyethylene Glycol Via Sol-Gel Method For Self-Cleaning Application
    ( 2023-01-01)
    Halin D.S.C.
    ;
    Azliza A.
    ;
    Razak K.A.
    ;
    ; ;
    Wahab J.A.
    ;
    Chobpattana V.
    ;
    Kaczmarek L.
    ;
    Nabiałek M.
    ;
    Jeż B.
    TiO2 is one of the most widely used metal oxide semiconductors in the field of photocatalysis for the self-cleaning purpose to withdraw pollutants. Polyethylene glycol (PEG) is recommended as a stabilizer and booster during preparation of water-soluble TiO2. Preparation of SnO2/TiO2 thin film deposition on the surface of ceramic tile was carried out by the sol-gel spin coating method by adding different amount of PEG (0g, 0.2g, 0.4g, 0.6g, 0.8g) during the preparation of the sol precursor. The effects of PEG content and the annealing temperature on the phase composition, crystallite size and the hydrophilic properties of SnO2/TiO2 films were studied. The X-ray diffraction (XRD) spectra revealed different phases existed when the films were annealed at different annealing temperatures of 350°C, 550°C and 750°C with 0.4 g of PEG addition. The crystallite sizes of the films were measured using Scherrer equation. It shows crystallite size was dependent on crystal structure existed in the films. The films with mixed phases of brookite and rutile shows the smallest crystallite size. In order to measure the hydrophilicity properties of films, the water contact angles for each film with different content of PEG were measured. It can be observed that the water contact angle decreased with the increasing of the content of PEG. It shows the superhydrophilicity properties for the films with the 0.8 g of PEG annealed at 750°C. This demonstrates that the annealed temperature and the addition of PEG affect the phase composition and the hydrophilicity properties of the films.
      2