Pusat Pengajian Kejuruteraan Bahan dan Sumber Mineral - Monograf
Browse
Recent Submissions
- Publication3d-printed pla scaffolds coated with chitosan–alginate hybrid for lead ion removal From aqueous solutions(2025-08)Muhammad Shamin Shafiq bin Abdul WahabThe global water crisis is increasingly exacerbated by heavy metal contamination, particularly lead (Pb²⁺), which poses serious risks due to its toxicity and persistence. Conventional removal methods are often costly, inefficient, and environmentally unsustainable. This research aims to design, and fabricate a novel 3D- printed bio-inspired composite scaffold utilizing chitosan-alginate coatings on polylactic acid (PLA) for enhanced heavy metal adsorption. This research presents a novel 3D-printed bio-inspired scaffold for enhanced Pb²⁺ adsorption, utilizing chitosan–alginate coatings on polylactic acid (PLA) frameworks. The scaffolds were fabricated using Fused Deposition Modeling (FDM) and treated with 1M NaOH prior to dip-coating with chitosan–alginate solutions in a 1:1 ratio. Surface characterization via SEM, FTIR, and zeta potential analysis confirmed uniform coating (164.2 ± 5 μm), presence of functional groups, and a stable negative surface charge (-29.7 mV). Batch adsorption tests using 100 mg/L Pb²⁺ solutions showed a maximum adsorption capacity of 77.52 mg/g with 92.93% removal efficiency. Kinetic modeling indicated pseudo-second-order behavior (R² ≈ 0.9919), suggesting chemisorption as the dominant mechanism. This research shown the potential of 3D-printed, biopolymer- coated scaffolds as efficient, sustainable adsorbents. This research demonstrates the potential of 3D-printed, biopolymer-coated scaffolds as efficient, sustainable adsorbents. The findings offer insights into polyelectrolyte complexation and provide a scalable platform for future water purification technologies. threat of heavy metal pollution is becoming increasingly serious and poses a threat to human health and the natural environment (Vidu et al., 2020). The sources of the
- PublicationEffect of polyvinyl alcohol (PVA) and polyethylene glycol (peg) to alumina slip casting product(2025-08-01)Yong, Jing RuiAlumina slip casting is a conventional shaping method that able to produce complex geometries with dimensional accuracy which is suitable to be used for furnace tubes and thermocouple protection tubes. Since there is limited research studies on the impact of lower molecular weight of additives to slurry’s rheological and final sintered product characteristics, low molecular weight PVA (binder) and PEG (plasticizer) were used in this study. The objective of this research is to evaluate the effects of varying concentrations of PEG and PVA and determine the optimal formulation that correlates between rheological of alumina slurry and characteristic of sintered alumina product. In this study, PVA (31000g/mol to 50000 g/mol) and PEG (1500 g/mol) were used at different concentration which is from 1.0 wt% to 4.0 wt% to evaluate their influence on slurry’s viscosity, casting time pH and sintered alumina product’s shrinkage measurement, density, porosity and flexural strength. The slurry formulations were prepared by using ball milling and slip cast into molds, followed by drying and sintering at 1650 °C. Based on the results obtained, viscosity of the slurry decreases as increasing the concentration of PVA. In contrast, the viscosity of slurry was reduced when the concentration of PEG increases. For casting time measurement, the lower the concentration of PVA and PEG, the greater the wall thickness formation. The optimal concentrations of PEG and PVA was sample S6 (1 wt% PEG + 1 wt% PVA) was determined as the optimal formulation since it shows the highest flexural strength (38.80 MPa), bulk density (3.88 g/cm³), the lowest porosity (3.05%), and rapid wall formation with sufficient shape retention and better appearance.
- PublicationImpact of acidic calcium phosphate solution concentration on the setting ability of β-tricalcium phosphate (β-tcp) and hydroxyapatite (HAP) porous granular cement(2025-08-07)Yeoh, Jing YiThis study investigates the effect of acidic calcium phosphate solution concentration containing citric acid on the setting ability of β-tricalcium phosphate and hydroxyapatite porous granular cements under physiological conditions as the materials can affect the properties in acidic condition. β-TCP and HAp granules were fabricated with calcium carbonate and dicalcium phosphate dihydrate at Ca/P ratios of 1.5 and 1.67 and followed by sintering at 1100°C with a heating rate of 5℃/min on 6 hours. Then, the acidic calcium phosphate solution was added with different concentration of citric acid (0.01, 0.10 and 1.00 mol/L) that act as inhibitor. The setting reaction was conducted under physiological conditions and setting reaction at 10 and 30 minutes. Characterization of X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), Fourier-transform infrared spectroscopy (FTIR), porosity and compressive strength were carried out. The study aims the effect of acidic calcium phosphate solution containing different oncentrations of citric acid on setting ability, porosity, phase transformation and compressive strength at 10 minutes and 30 minutes. At 10 minutes, β-TCP granular cement with 0.10 mol/L citric acid has achieved the highest compressive strength (0.45 MPa) due to effective DCPD crystal interlocking between granules. While HAp granular cement was unsuccessful to set at all concentrations of citric acid. After 30 minutes, β-TCP granular cement with 1.00 mol/L citric acid had highest compressive strength (0.26 MPa) with highest porosity. β β while HAp granular cement partially set for 1.00 mol/L citric acid with lowest compressive strength (0.04 MPa) that indicate strong inhibition of DCPD crystallization by citric acid. Overall, β-TCP granular cement set faster and effectively than HAp granular cement as their higher solubility and reactivity in acidic environments. Also, the setting times clinically acceptable for surgical use, while HAp requires further optimization.
- PublicationEffects of C70 in pectin thin film on configurable Resistive switching chracteristics(2025-08)Wong, Yi ShengAlthough inorganic-based resistive switching (RS) devices have shown promising performance to fulfil the potential requirement of high-speed dense memories, it can lead to the production of e-waste which harms the environment. Hence, bio-organic-based RS devices are developed as a sustainable alternative. The main objective of this research is to improve the RS performance of pectin derived from citrus peel RS device through comparing the effect of different Fullerene C70 concentration (0 wt%, 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 10 wt%, 20 wt%, 25 wt% and 30 wt%) incorporated into 5 mg/ml pectin precursor solution by solvent exchange technique to form a thin film, compliance current, number of sweeping cycles, and solvent used to functionalize C70 on the RS performance and different configurable memory mode of the device. A compliance current (Icc) is required for a ReRAM device in order to prevent the dielectric switching layer from permanently breaking down during the forming/setting process. Toluene and tetrahydrofuran (THF) were used as the solvents to functionalize 30 wt% of C70 to compare the effect of solvent used on the performance indicators of the device. The prepared precursor solutions were spin-coated onto ITO-coated PET substrates and dried at 140oC for 2 h before sputtered with gold/platinum top electrode. Fourier Transform Infrared (FTIR) Spectroscopy, Energy Dispersive X-ray (EDX) Spectroscopy, goniometer, zeta potential analyser, Atomic Force Microscopy (AFM), and Semiconductor Parameter Analyzer (SPA) were used to characterize the raw materials, dried memristive thin film, and RS behaviour of the memory devices. The results showed that the device with 25 wt% C70 showed the highest ON/OFF current ratio of 5.95 x 102, which is an increase of nearly 2 orders of magnitude compared with pristine pectin RS device. Using toluene gave better performance compared to using THF as a solvent for C70, with the 30 wt% (toluene) device having a higher ON/OFF current ratio of 1.40 x 102 compared to 30 wt% (THF) 3.45 x101, which is about 1 magnitude higher. The pristine pectin and 25 wt%-C70 pectin device exhibited configurable memory between non- memory, Write-Once Read-Many WORM, and bipolar RS by varying the Icc. In conclusion, this research shows the potential of C70 as a promising additive to enhance the RS performance in configurable bio-organic-based RS devices.
- PublicationEffect of ultraviolet (uv) and heat sterilization on the properties of Dicalcium phosphate dihydrate coated β-tricalcium phosphate granules(2025-08-06)Wong, Kai Xiβ-Tricalcium phosphate (β-TCP) has attracted much attention as an artificial bone substitute owing to its biocompatibility and osteoconductivity. However, the sterilization method for Dicalcium Phosphate Dihydrate (DCPD)-coated β-Tricalcium Phosphate (β-TCP) granules still not discover yet. Hence, this study is carried out to investigate the effects of ultraviolet (UV) and heat sterilization on the properties of 10 mol% Dicalcium Phosphate Dihydrate (DCPD)-coated β-Tricalcium Phosphate (β- TCP) granules. The granules were sterilized using UV light (100 mJ/cm²) and heat treatment (170°C for 30 minutes) under physiological body conditions. Characterization techniques such as XRD, SEM, FTIR and porosity analysis tests were performed on the sterilized granules to assess their structural and chemical properties. XRD and SEM analysis revealed that both sterilization methods influenced the crystalline and surface morphology of the β-TCP granules. UV sterilization preserved the integrity of the β-TCP structure while heat sterilization induced dehydration and phase transitions, including slight alterations in the DCPD coating. These changes increased the granules’ porosity by 18%, while their compressive strength decreased by approximately 20%. Overall, this study successfully demonstrates that sterilization techniques affect the properties of DCPD-coated β-TCP granules, with heat sterilization causing more significant structural and mechanical alterations compared to UV sterilization.