Now showing 1 - 8 of 8
  • Publication
    Synthesis and Characterisation of Self-Cleaning TiO2/PES Mixed Matrix Membranes in the Removal of Humic Acid
    ( 2023-04-01)
    Poon Y.K.
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    ; ; ;
    Abdullah N.Y.
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    ;
    Abdullah N.S.
    Membrane application is widespread in water filtration to remove natural organic matter (NOM), especially humic acid. However, there is a significant concern in membrane filtration, which is fouling, which will cause a reduction in the membrane life span, a high energy requirement, and a loss in product quality. Therefore, the effect of a TiO2/PES mixed matrix membrane on different concentrations of TiO2 photocatalyst and different durations of UV irradiation was studied in removing humic acid to determine the anti-fouling and self-cleaning effects. The TiO2 photocatalyst and TiO2/PES mixed matrix membrane synthesised were characterised using attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy, X-ray powder diffraction (XRD), scanning electron microscope (SEM), contact angle, and porosity. The performances of TiO2/PES membranes of 0 wt.%, 1 wt.%, 3 wt.%, and 5 wt.% were evaluated via a cross-flow filtration system regarding anti-fouling and self-cleaning effects. After that, all the membranes were irradiated under UV for either 2, 10, or 20 min. A TiO2/PES mixed matrix membrane of 3 wt.% was proved to have the best anti-fouling and self-cleaning effect with improved hydrophilicity. The optimum duration for UV irradiation of the TiO2/PES mixed matrix membrane was 20 min. Furthermore, the fouling behaviour of mixed matrix membranes was fitted to the intermediate blocking model. Adding TiO2 photocatalyst into the PES membrane enhanced the anti-fouling and self-cleaning properties.
  • Publication
    Parameters adjustments for facile synthesis of high magnetization iron oxide nanoparticles from natural sand
    ( 2024-02-01)
    Wahfiudin A.
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    Pramata A.D.
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    Wicaksono S.T.
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    ; ; ; ;
    This study explores the synthesis of Superparamagnetic Iron Oxide Nanoparticles (SPIONs) by leveraging natural iron sand and steel wool as primary raw materials within the co-precipitation method, which reduces the cost of production compared to the commercial counterparts. The research systematically investigated the influence of the diethylamine percentage, annealing time and annealing temperature on the SPIONs’ synthesis from natural iron sand by the co-precipitation method. Fe3O4 with varying crystallite sizes, ranging from 11.5 to 14.7 nm, were confirmed. SEM highlighted the nanoparticle agglomeration, a concern addressable through surface modification techniques, as further emphasized by TEM, which confirmed the nano-scale dimensions. Magnetic saturation values were confirmed by VSM, ranging from 37 to 51 emu/g. These values established the superparamagnetic behavior, rendering the nanoparticles suitable for versatile applications. The study identifies a potential threshold effect of the diethylamine concentration on the magnetic saturation and suggests an optimum annealing temperature for energy efficiency. This research contributes valuable insights into harnessing natural iron sand for SPION synthesis, advancing cost-effective and sustainable approaches in nanomaterial development, while emphasizing the importance of parameter customization for producing high-quality SPIONs.
  • Publication
    Facial synthesis of colloidal stable magnetic nanoparticles coated with high hydrophilic negative charged poly(4‐styrenesulfonic acid co‐maleic acid) sodium for water remediation
    (Wiley, 2023)
    Lim Chuan Chuan
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    ; ; ; ; ;
    Sigit Tri Wicaksono
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    Azzah Dyah Pramata
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    Siti Zullaikah
    The enhancement of the colloidal stability of magnetite nanoparticles (MNPs) for environmental‐related fields has greatly attracted researchers' attention. This study used a high hydrophilic negatively charged polyelectrolyte, poly(4‐styrenesulfonic acid co‐maleic acid) sodium (PSAAS), to enhance the colloidal stability of MNPs. Coating of the naked MNPs with PSAAS polyelectrolyte is a simple and rapid method to obtain colloidally stable MNPs while sustaining the chemical reactivity of MNPs in water purification. The prepared PSAAS‐coated MNPs were characterized by scanning electron microscope, energy dispersive X‐ray, Fourier transform infrared, zeta potential analysis, transmission electron microscope and X‐ray diffraction. Moreover, the colloidal stability and adsorption performance tests of these naked MNPs and PSAAS‐coated MNPs (with different concentrations of PSAAS coated) were investigated and compared. PSAAS‐coated MNPs with 0.001 g/ml PSAAS coating possessed the best colloidal stability and the highest methylene blue (MB) dye removal efficiency (94.53 ± 0.69%). The adsorption isotherm and kinetic studies for the adsorption of MB onto PSAAS‐coated MNPs were well‐described by the Langmuir model and pseudo‐second‐order kinetic model. These magnetic adsorbents, with high separation efficiency, simple and low production cost and recyclable property, are promising as practicable adsorbents in water treatment.
  • Publication
    Polyvinylidene Fluoride-co-Polytetrafluoroethylene (PVDF-co-PTFE)/Deep Eutectic Solvent (DES) impregnated membrane for carbon dioxide separtion
    Deep Eutectic Solvent (DES) is a new type of organic slovent that have been considered as an attractive liquid medium to be incorporated in liquid membrane (LM) due to high solubility of carbon dioxide (CO₂). However, DES is still considered as a new and fresh liquid, hence the performance of supported-DES-membrane has not been reported yet. Hence, this study aims to synthesize and characterize polyniylidene fluoride-co-polytetrafluoroethylene (PVDF-co-PTFE) membrane, followed by preparation of supported-DES-membrane and evaluating the prepared LM for carbon dioxide/nitrogen (CO2/N2) separation. Asymmetric PVDF-co-PTFE membrane was prepared via phase inversion method using non-solvent induced phase separation (NIPS). The selection of suitable solvent and polymer concentration were studied first for membrane support preparation. Polymer solution prepared by using N,N-dimethylacetamide (DMAc) showed the lowest viscosity (7800 cP) and hence, produce a membrane with a larger size (115.0 μm) and high quantity of finger-like macrovoids with highest porosity (57.6%) compared with other solvents. Meanwhile, increasing of polymer concentration resulted in lower porosity due to decreasing of macrovoids pore size shown by scanning electron microscope (SEM) micrograph. Furthermore, DES was prepared by the mixing of choline chloride (ChCI) and ethylene glycol (EG), then impregnated into the membrane matrix via vacuum method. In order to increase DES loading,selection and addition of pore additives as well as manipulating the coagulant bath medium were carried out. The CO₂ separation performance of LM was tested using gas permeation at variation of pressure and flow rate. The membrane characterizations as well as gas permeation test results showed that supported-DES-membrane fabricated by using 6 wt.% polyethylene glycol (PEG), 20wt.% polymer and 74 wt.% DMAc in a polymer solution and having a mixture of 25 wt. % of ethanol and 75 wt. % distilled water as a coagulant bath shows the highest porosity with a combination of finger and sponge-like microstructure. From energy dispersive X-ray spectrometer (EDX) and SEM analysis, the respected membrane was able to hold DES at the highest percentage. The optimum CO₂ permeability recorded in this study was 4.41 x 10`6 barrer with CO₂/N2 selectivity at 8.28. Gas separation performance using DES as a solvent in LM demonstrated 99% better as compared to conventional ionic liquid, but a bit lower in terms of CO₂/N2 selectivity. Hence, the promising result obtained in this study demonstrates the potential of DES for gas separation, especially in CO₂ separation.
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  • Publication
    Preparation of supported-deep eutectic solvent membranes: Effects of bath medium composition on the structure and performance of supported-deep eutectic solvent membrane for CO2/N2 gas separation
    Polyvinylidene fluoride-co-polytetrafluoroethylene, PVDF-co-PTFE polymer was used as a membrane support. The asymmetric membranes were formed by immersion of casted membrane film into the coagulation bath. This work manipulated the coagulant bath medium by mixing ethanol with distilled water at different weight percentages (0, 25 and 50 wt. % of ethanol). The structures of fabricated membranes were observed to have different morphologies. Higher ethanol content altered the membrane structure from finger-like to sponge-like structure, and hence differed in membrane porosity. Vacuum-based technique was chosen to impregnate the deep eutectic solvent (DES) into the pores of membrane support. DES was prepared by mixing choline chloride (ChCl) and ethylene glycol at a ratio of 1:3. Scanning electron microscopy (SEM) was used to study the membrane morphology changes while in order to determine the immobilization of DES, energy dispersive X-ray (EDX) analysis was used. The porosity of fabricated PVDF-co-PTFE membrane was determined by means of gravimetric method. Lastly, the membrane separation performance using CO2 and N2 gasses were used to determine the capability of the supported-DES-membrane. The results demonstrated the highest immobilization of DES in supported membrane pores was achieved when combination of 25 wt. % of ethanol and 75 wt. % distilled water was used as a coagulant bath medium. The respective membrane has 74.5% porosity with the most excellent performance of CO2 separation at 25.5 x 103 GPU with CO2/N2 selectivity of 2.89.
      9  36
  • Publication
    Mechanical properties and biodegradability of polylactic acid/acrylonitrile butadiene styrene with cellulose particle isolated from Nypa fruticans husk
    (Universiti Malaysia Pahang Al-Sultan Abdullah Press, 2020) ;
    L. C. Cheah
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    Polylactic acid is a biodegradable polymer derived from renewable resources, showing potentials in replacing traditional petroleum-based polymers, yet its brittleness limits its applications. Thus, blending polylactic acid with acrylonitrile butadiene styrene as well as incorporation of fillers were used to enhance the mechanical and biodegradability properties of polylactic acid by extrusion compounding. The aims of this study to produce and investigate PLA/ABS blend incorporated with natural filler, NFH and IC to improve the properties pf PLA/ABS blends. Two types of fillers used were Nypa fruticans husk and isolated cellulose from Nypa fruticans husk which was obtained by using Soxhlet extraction. Transform Infrared spectroscopy analysis was used to characterize and verified the extracted substance was isolate cellulose. Tensile, impact and biodegradation test were conducted to investigate the mechanical and biodegradability properties. The optimum blend ratio for polylactic acid/acrylonitrile was 75/25 php base on previous studies, and it was found that the incorporation of both fillers, Nypa fruticans husk and isolated cellulose from Nypa fruticans husk had decreased the tensile strength, elongation at break and impact strength of the composite however increased the Young’s Modulus and biodegradation weight loss. Meanwhile, at similar filler content, the tensile strength, Young’s modulus and biodegradation weight loss of polylactic acid/acrylonitrile butadiene styrene blend incorporated with isolated cellulose were higher value compared to polylactic acid/acrylonitrile butadiene styrene blend incorporated Nypa fruticans husk. Furthermore, morphological studies showed a well-coated filler by matrix and reduction of filler pull out when isolated cellulose was incorporated in polylactic acid/acrylonitrile butadiene styrene blend. Therefore, it was found that the incorporation of isolated cellulose in polylactic acid/acrylonitrile butadiene styrene blend, shows higher mechanical and biodegradation properties than polylactic acid/acrylonitrile butadiene styrene blend incorporated with Nypa fruticans husk.
      4  9
  • Publication
    Facile synthesis of hybrid-polyoxometalates nanocomposite for degradation of cationic and anionic dyes in water treatment
    (Academic Enhancement Department, King Mongkut's University of Technology North Bangkok, 2025-03)
    Wei Wei Leow
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    Alvin Duke
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    ; ;
    Norazharuddin Shah Abdullah
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    ; ;
    Photocatalysis emerges as a promising method for treating organic dye contaminated wastewater. This process involves the use of photocatalysts through light activation, typically semiconductors such as titanium dioxide (TiO2) or polyoxometalates (POM) to generate reactive species capable of degrading organic pollutants. Several factors influence the photodegradation of ionic and cationic dyes including chemical properties, reaction mechanism and degradation efficiency. This work evaluated photodegradation performance of methyl orange (MO) and malachite green (MG) dyes using hybrid-polyoxometalate (HPOM) photocatalyst. Fourier Transform Infrared Spectroscopy (FTIR) identified the characteristic band at 3463.66 cm–1 (O-H) and 997.74 cm–1 (W-O). Scanning Electron Microscopy (SEM) revealed the presence of rod-like and granular structures in HPOM, representing silver acetate and sodium tungstate. X-ray diffraction (XRD) confirmed characteristic peak of Keggin structure, revealing high crystallinity of HPOM. UV-assisted photodegradation was evaluated on different parameters (initial dye concentration, photocatalyst dosage and pH), highlighting HPOM’s better affinity for degrading cationic dye. The optimum photodegradation conditions for MG and MO dyes were 20 ppm dye concentration, 100 mg photocatalyst dosage, and pH 7 and 8, respectively. The kinetic data was fitted with the Langmuir Hinshelwood kinetic model, indicating pseudo-first-order kinetics. HPOM exhibited a higher rate constant, k for MG (k = 0.0068 min–1) than MO (k = 0.0029 min–1).
      1  1
  • Publication
    Fabrication of biodegradable Polylactic Acid (PLA) membrane for reverse osmosis process
    ( 2023) ;
    Nuratiqah Baharudin
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    Nora Jullok
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    ;
    Juhana Jaafar
    Polylactic Acid (PLA) is a pronounced biodegradable polymer which has been developed to be used in a broad range of applications due to its biocompatibility and would be able to solve the problems suffered from commercial polymeric membrane used in reverse osmosis (RO). Asymmetric flat sheet PLA membrane were fabricated via phase inversion technique using non-solvent induced phase separation (NIPS). Different weight % ratio of ethanol and water as a coagulant bath medium (0:100, 20:80, 40:60, 80:20 and 100:0) were varied to investigate the effect of different membrane microstructure of the PLA membrane performance in reverse osmosis process. The prepared membranes were characterized through several characterizations and undergo the performance test using dead end filtration. Increasing ethanol contents resulted in higher porosity and lower contact angle due to forming of pores sparsely on the membrane surface. The morphologies of membrane top surface was strongly affected by the medium of coagulant bath. Two membranes fabricated using 40 wt,% and 80 wt.% ethanol as a coagulant bath were carried out with performance test. The findings revealing the highest water flux and permeability was shown by a membrane fabricated from 80 wt. % of ethanol and 20 wt. % of distilled water. It was also found that the respective membrane showed the highest salt rejection capability.
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