bluuebunny/crossref_metadata_2025 huggingface dataset:
Incorporation of Hybrid Pre-Dispersed Organo-Montmorillonite/ Destabilized Bentonite Nanofillers for Improving Tensile Strength of PEVA Copolymer with 40% Vinyl Acetate Composition
Authors: Mohammed Fitri Tuty Fareyhynn , Osman Azlin Fazlina , Othman Rahimah , Mustafa Zaleha
Published: September 2020

In this work, soft and flexible poly (ethylene-co-vinyl acetate) (PEVA) with 40% vinyl acetate (VA) composition was used as matrix material to form nanocomposites with single nanofiller (organo-montmorillonite (OMMT) or Bentonite (Bent)) and hybrid nanofillers (OMMT+Bent in the ratios of 4:1, 3:2, 2:3 and 1:4). In order to achieve greater exfoliation and dispersion of the hybrid nanofillers in the PEVA matrix, the pre- dispersing and destabilization technique was applied to the O-MMT and Bent, respectively. The procedures were done prior to the melt compounding process of the nanocomposite. A tensile test was done to evaluate the mechanical properties of the resultant nanocomposites and to allow the selection of the best OMMT/Bent ratio for the production of the hybrid nanocomposite. The structure and fractured surfaces of the neat PEVA and nanocomposite were analyzed using Fourier Transform Infrared (FTIR) and Scanning Electron Microscopy (SEM), respectively. Results indicated that the addition of hybrid pre-dispersed OMMT/destabilized bentonite nanofillers into the PEVA matrix resulted in greater mechanical performance as compared to the single OMMT or single Bent nanofiller. The best achievement in the tensile strength and elongation at break of the PEVA hybrid nanocomposite was obtained when the hybrid nanofillers was added in the ratio of 4:1 (OMMT: Bent). The SEM analysis showed that the PEVA hybrid nanocomposite with 4OMMT: 1Bent had greater matrix deformation than the neat PEVA when subjected to tensile load. This mechanical deformation could be related to the increased flexibility of the PEVA chains which facilitated more energy absorption during the stretching of the material. Apparently, this mechanism acted as a matrix toughening process which allowed the increment of both tensile strength and elongation at break values of the PEVA upon the addition of the hybrid nanofillers.
Mechanical and Thermal Properties of Hybrid Non-Woven Kenaf Fibre Mat-Graphene Nanoplatelets reinforced Polypropylene Composites
Authors: Mohd Haziq Amri , Abu Bakar Mohamad Bashree , Masri Mohamad Najmi , Sulaiman Muhammad Azwadi , Amini Mohd Hazim Mohamad , Mamat Sarizam , Mohamed Mazlan
Published: September 2020

In this study, kenaf fibre mat (NWKFM)-graphene nanoplatelets (GNP) reinforced polypropylene (PP) composites were fabricated by using compression moulding. The hybridization was done to enhance the mechanical and thermal properties by adding different amount of graphene nanoplatelets as filler in the biocomposite samples. Pure PP and nanocomposite samples of PP+GNP were also fabricated. Maleic anhydride grafted polypropylene (MAPP) was used as a coupling agent to increase the interfacial adhesion of matrix and reinforcement of the biocomposites and hybrid composites samples. The chemical composition and constituent changes were studied by using Fourier transform infrared spectroscopy (FTIR) analysis. The mechanical properties in term of flexural and tensile were tested using a universal testing machine (UTM). Thermogravimetric analysis (TGA) was carried out to determine the thermal stability of the composite’s samples. Overall, the results show that the stiffness properties (young’s and tensile modulus) of pure PP and biocomposites enhanced with addition of GNP. The flexural strength also shows promising result with the inclusion of GNP. However, the tensile strength shows a reduction with the addition of GNP. The TGA results reveal that the addition of GNP increases the thermal stability of pure PP and the biocomposites based on the comparison of Tonset values.
Mechanical Properties of Recycled Polypropylene Filled with Aluminium Hydroxide
Authors: Goh Yong Guan , Sufian Anis Sofia , Mohamad Noridah , Afiqah Nur
Published: September 2020

The present work aims to study the prospects of the efficient utilization of aluminium hydroxide (Al(OH)3 as a filler for thermoplastic recycled polymer. Recycled polypropylene (rPP) has been used as polymer matrix to prepare composites with different levels (25 and 50 wt.%) of aluminium hydroxide filler. Maleic anhydride-grafted polypropylene (MAPP) coupling agent has also been incorporated into rPP composites to facilitate particle dispersion. MAPP treated composites have shown up to 20% improvement in tensile strength and an increment of up to 33% in tensile modulus as compared to neat rPP prepared at 25 wt.% and 50 wt.% Al(OH)3 filler content, respectively. MAPP surface treatment enhancement of interfacial adhesion between rPP matrix and Al(OH)3 filler is evident through SEM micrographs. Al(OH)3 filler strongly influences the flammability of rPP composites, with a significant reduction in average ignition time. The flame retardancy of MAPP treated rPP composite surpasses untreated rPP composite, despite the insignificant amount of difference between the two.
The Simultaneous Effect of Extrusion Ratio and Solution Heat Treatment on the Microstructure and Tensile Properties of Extruded Al-15%Mg2Si- 1.0%Gd Composite
Authors: Ghandvar Hamidreza , Faiz Wan Famin , Abu Bakar Tuty Asma , Idris Mohd Hasbullah
Published: September 2020

The effect of extrusion ratios and solution heat treatment on microstructure and tensile properties of extruded Al-15%Mg2Si-1.0%Gd composite was investigated. The as-cast composite was hot extruded using three different dies and solution heat treated. After conducting heat treatment on extruded samples, microstructure alteration was examined using scanning electron microscope (SEM). Furthermore, mechanical properties of the composites were studied with tensile test. The results demonstrated that extruded and heat treated composite possesses higher strength and ductility compared to as-extruded composites. It was also found that the extrusion and heat treatment processes altered the morphology of primary Mg2Si particles as well as reduction in their size especially when the extrusion ratio increases. Fracture surface examination revealed a transition from ductile fracture in as-extruded samples to more ductile fracture in extruded and heat treated ones. This can be attributed to the change in size and morphology of primary Mg2Si particles as well as fragmentation of Gd intermetallic compounds.
Compatibility of Palm Biodiesel Blends on the Existing Elastomer Fuel Hose in Diesel Engine with Approach of Dynamic Test Rig: A Concept Study
Authors: Sa'at Narisa , Samsuri Ariffin , Latif Noradila Abdul , Nasir Nurul Fitriah , MADON RAIS HANIZAM BIN MADON , Osman Shahrul Azmir
Published: September 2020

Elastomer is one of the important material for the hoses, sealants and tubes in the components of fuel delivery system in diesel engine vehicles due to the factor of compatibility with diesel fuel. However, concern were arise that presence of alcohol, fatty acid component and other factors such as water content in the alternative fuels which is blended biodiesel fuel and different chemical composition from the diesel fuel may increase further uncertainty to the consumer of diesel engine or diesel engine manufacturers in terms of compatibility issue. Thus this paper intends to assess current and typical test standards on their efficacy of representing the fuel system of diesel engine vehicles. Respectively, ASTM D471 are based on laboratory immersion studies and the experimental conditions are differ from the real service conditions in the fuel system of diesel engine vehicles. Even though number of previous studies regarding to the compatibility of elastomer components has been reported, there is a need to set up the exact material that present in the fuel system of diesel engine vehicles. This is especially right for elastomers since their resistance is mainly depends on their elemental compositions. As such, introduction of the dynamic testing approach that may be applied when assessing the compatibility study between blended biodiesel fuel that simulate the actual fuel system of a diesel engine vehicles before carrying out in the field trials.
Comparative Study on the Performance of ZTA Cutting Tool with the Addition of Different Particle Size of MgO Additive
Authors: Mudzaffar Raqibah Najwa , Khairy Hanani Hani Mohd. , Zaki Nur Khairunnisa Mohd. , Azhar Ahmad Zahirani Ahmad , Manshor Hanisah , Rejab Nik Akmar , Ali Afifah
Published: September 2020

This paper investigated the performance of ZTA cutting tool with the addition of different particle size of MgO additive. Therefore, the objective of this research is to compare the effects of machining parameters on tool wears of ZTA cutting tools added with micro and nanoparticle of MgO. The experiments were conducted using BridgePort-Romi Powerpath CNC machine using a tool holder Sandvik Coromant (CoroTurn CCLNR 164D-4) to hold the cutting tools properly. The parameters are set up as cutting speeds used between range 354 to 472 m/min, feed rate from 0.1 to 0.5 mm/rev with a constant depth of cut of 0.2 mm. Three types of wear were analyzed which are flank wear, crater wear and tool chipping. Flank wear and crater wear images captured using measuring microscope (NIKON MM-400/L) and the crater wear areas are analyzed using MatLab programming software. Tool chipping is observed via SEM (JEOL JSM-5600). The experimental result shows that flank wear and crater wear increase when cutting speed and feed rate increase. ZMN cutting tool shows lower value of flank wear at 0.143 mm and 3.741 mm2 for crater wear than ZMM, 0.321 mm and 3.808 mm2 respectively. On the contrary, cutting speed did not affect the tool chipping severely as feed rate. Moreover, ZMN also shows that the tool breakage occurred severely than ZMM due to the high load on the tool nose.
Comparison between Solid State Reaction and Coprecipitation Method of Titanium Oxide Addition on the YBa2Cu3Oδ Ceramics
Authors: Ali Arlina , Ameram Nadiah Bte , Auli Nik Alnur
Published: September 2020

In this work, comparison of TiO2 additions on the physical properties of YBa2Cu3Oδ superconductor system with nominal starting compositions at x= 0, 1, 2, and 5 wt.% was studied derived via solid state reaction and co-precipitation method. The samples were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The result from XRD shown that all the samples were polycrystalline for solid state reaction, while single phase appear for co-precipitation methods. The intensity of the peak become higher with increasing amount of TiO2 addition indicating the presence of increased amount of the unreacted in the samples. The refine lattice parameters indicated that all the samples have an orthorhombic crystal structure without occurrence of orthorhombic-tetragonal phase transformation. Furthermore, from SEM images for solid state reaction and co-precipitation method showed that the grain size of the samples decreased with TiO2 increased. Small addition of TiO2 derived from co-precipitation method enhanced the YBCO microstructures.
Effect of Soaking Time on Crystal Structure of Lithium Aluminosilicate Glass Ceramic
Authors: Lutpi Husniyah Aliyah , Hasmaliza Mohamad , Abdullah Tuti Katrina
Published: September 2020

Formation of crystal structures in glass ceramic is influenced by the heat treatment of parent glass. Most of research often studied on the important of sintering temperature and its soaking time. In this study, the effect of soaking time (3, 4 and 5 hours) during melting process (1550 °C) on crystal structures of Lithium Aluminosilicate (LAS) glass ceramic was conducted. All samples were then sintered at 900 °C for 30 minutes. The amorphous phase was identified prior to sintering process and transformed into crystalline phase for all samples after sintering process in XRD analysis. Major crystalline phase of high quartz solid solution and β-spodumene (LiAlSi2O6) were observed and higher intensity peak is found as the soaking time is longer. The microstructure of the sintered samples was observed under SEM and the particles were displayed an evidently growth of the grain as function to the soaking time. The functional groups of Si-O-Si and Si-O(Si, Al) bonding were appeared in fourier-transform infrared spectroscopy (FTIR) analysis corresponding to the silicates and aluminosilicate bonding. The results achieved present 5 hours soaking time during melting process was the optimum soaking time for melting LAS glass at 1550 °C.
Formation of Yttria Aluminium Garnet by Microwave Sintering
Authors: Abdul Halim Ahmad Amirul Ashraf , Sudin Izman , Wan Ali Wan Fahmin Faiz , Yasak Roslin , Md. Sirat Rozlina , Othman Mohamad Ariff , Abdullah Norazharuddin Shah , Ahmad Zainal Arifin
Published: September 2020

Polycrystalline yttrium aluminium garnet (YAG) ceramic has been prepared using microwave sintering. Micron-sized of Al2O3 and Y2O3 powders were mixed through in house fabrication mixer for 24 hours before calcined at 1100 °C and palletization process. The effect of sintering parameters on the microstructures was observed at various and holding times. X-ray diffraction (XRD) analysis was carried out to determine and quantify phase transformation with respect to these parameters. It was found that three phases namely YAM (Y4Al2O9), YAP (YAlO3) and YAG have been identified. While both grain sizes and density of sintered samples were found increased from 1.4 μm to 2.46 μm and 90% to 98%, respectively. Therefore, microwave sintering has a significant effect on the densification behavior of YAG.
Investigation of CaCu3Ti4O12 Precursor by Simultaneous TGA and DSC Analysis in Oxygen Environment
Authors: Daud Noruzaman , Mohamed Julie Juliewatty , bin Abu Mohamad Johari , Ab Rahman Mohd Fariz , binti Hassan Siti Roshayu , Mohammed Hasmaliza , Ahmad Zainal Arifin
Published: September 2020

CCTO consist of huge dielectric constant up to 105 at temperature range -173 °C to 326 °C becomes an attraction to investigate the CCTO ceramics. The samples were tested using simultaneous thermogravimetry (TGA) and differential calorimetry (DSC) measurement in dual atmospheric gases condition by flowing nitrogen and oxygen gas. Phase changes of CCTO precursor were analyzed by X-ray diffraction machine. The samples CT900 and CT1000 occur both of mass loss and reabsorption due to the oxygen-rich environment. The mass loss for both samples CT900 and CT1000 has complete curves of CaCO3 decomposition. Sample CT900 shows incomplete of heat flow changes compare to samples CTNML and CT1000. The result shows that the formation of the CCTO phase structure does not depend on the oxygen gas environment but also requires specific heat of energy and temperature to changes the phase structure. DSC graph shows two magnitudes of heat flow changes for sample CT1000 that are an endothermic at temperature peak points 824 °C and 984 °C.
Microstructural and Dielectric Responses of Calcium Copper Titanate Added Soda-Lime Glass for High Frequency Devices
Authors: Ab Rahman Mohd Fariz , Ain Mohd Fadzil , Mohamed Julie Juliewatty , binti Hassan Siti Roshayu , Ahmad Zainal Arifin
Published: September 2020

The microstructures and dielectric responses of calcium copper titanate (CCTO) ceramics with soda-lime glass addition was investigated. The addition of soda lime glass was varied from 0-5 wt.% by solid-state reaction. The dielectric properties of CCTO indicated that dielectric constant was increased while dielectric loss was decreased after glass addition. The SEM micrographs showed the grain size of CCTO was decreased while the grain boundaries area of CuO + glass were increased after the addition of soda-lime glass. Both XRD patterns of CCTO and CCTO-soda lime glass sintered samples showed the formation of CCTO phase with minor peaks of CuO phase, respectively. These results indicated that soda-lime glass addition gave a significant effect on the microstructural and dielectric responses of CCTO ceramics.
Microstructure and Mechanical Behavior of CaCu3Ti4O12 Ceramics Hollow Fiber Prepared via Dry/Wet Spinning Method
Authors: Ahmadipour Mohsen , Otitoju Tunmise Ayode , Arjmand Mohammad , Ahmad Zainal Arifin , Pung Swee Yong
Published: September 2020

Dry/wet method was used to prepare CaCuTi4O12 (CCTO) hollow fibers (HFs) and then the structural and physico-mechanical properties of HFs were characterized by XRD, FESEM, BET and tensile strength, respectively. The outer diameter and thickness of CCTO HFs were found to be 650 μm and 390 μm, respectively. A finger-like macrovoids and sponge-like was observed inside the membrane with a denser structure in the outer layer. It was observed that the crystallite size was increased from 28.5 nm to 37.0 nm while the average pore diameter was decreased from 34.65 nm to 29.16 nm in CCTO hollow fiber with 1.0 wt.% CCTO. In addition, the tensile strength of HFS was significantly improved from 4.84 MPa to 5.54 MPa and elongation at break was decreased from 6.97 % to 5.09 % which is ascribed to the reduction in porosity. All the results indicated the significant effect of CCTO content on properties of CCTO hollow fibers. The finding in this study could lead to a new direction to enhance the properties of HFS with potential application in membranes.
The Effect of Pressing Load on 8 mol% Yttria Stabilized Zirconia Grade 204NS-G
Authors: Selvaraj Tinesha , Johar Banjuraizah , Khor Shing Fhan
Published: September 2020

The aim of this study is to understand the compaction characteristics of as received granulated 8 mol% yttria-stabilized zirconia (8YSZ). The samples were compacted at different loads and sintered at 1550 °C with the heating rate of 5°C/min for 5 hours. The densification, morphology analysis and crystal structure of the sintered were compared. The densification of granulated 8YSZ achieved 67% as increasing pressing load (0.1 tonne to 0.4 tonne). Rietveld quantitative phase analysis demonstrates that the tetragonal-ZrO2 phase reduces in granulated 8YSZ. The amount of cubic-ZrO2 phase dramatically dropped for both granulated as the pressing load increased. From the morphology analysis, granulated sample found to be porous observed on the surface as compaction load applied. Compaction load has no significant effect on the densification of granule sintered 8YSZ in the current study. The maximum densification was only reached 67% by using granulated 8YSZ powder with 0.4 tonne pressing load.
Thermal and Dynamic Mechanical Behaviours of CCTO/ENR-25 Composite
Authors: Sharifuddin Syifa' Muhamad , Mat Nor Mohd Shukri , Pabli Fathin Asila Mohd , Luangchuang Piyawadee , Chueangchayaphan Wannarat , Sulaiman Muhammad Azwadi
Published: September 2020

A study on polymer-ceramic composite, CaCu3Ti4O12 (CCTO) embedded in epoxidised natural rubber (ENR-25) were successfully fabricated through mixing method using an internal mixer and two-roll mill followed by hot-pressed via compression moulding for a potential electronic device such as a flexible capacitor. CCTO powders were successfully synthesised through a solid-state reaction and calcined at 900 °C for 12 hours. The ENR-25 was blended with 0, 20, 40, 60, 80, 100, and 120 phr (part per hundreds of rubber) of CCTO powders. Thermal stability and degradation are crucial properties for the composite based polymer. Therefore, thermogravimetric and differential scanning calorimetry (TGA/DSC) used to find out the thermal reaction and degradation mechanism of CCTO/ENR-25 composites. Besides, dynamic mechanical analysis (DMA) also used to investigate glass transition temperature (Tg) and storage modulus. TGA/DSC showed a two-step degradation mechanism with increasing thermal stability over increasing filler content of CCTO and only showed a major endothermic reaction. However, for DMA there is no significant difference in Tg value between each composite but showed high storage modulus up to 4398 MPa for 120 phr. High storage modulus indicates the high stiffness of the composite. In conclusion, the addition of filler content will show high thermal stability, storage modulus, and stiffness of CCTO/ENR-25 composites.
Effect of H2/N2 Mixtures on Reduction of Nickel Oxide
Authors: Che Abdullah Salmie Suhana , Mohd Nasri Nur Nadia , Ahmad Zaidi Nur Hidayah , Salleh Siti Hawa , Wan Nordin Imaduddin Helmi
Published: September 2020

This paper describes the reduction of nickel oxide under different gas mixture. The influence of gas mixture on phase, density, morphology and pore size of reduced nickel oxide were studied. Nickel oxide pellets sintered at 1400 °C were reduced under various hydrogen-nitrogen gas mixtures, namely 40% H2-60% N2, 60% H2-40% N2, 80% H2-20% N2. Phase identification, density measurement and observation of morphology were conducted on samples before and after reduction process. Under all gas mixtures, nickel oxide was completely reduced to nickel. Density of the samples decreased in the range of 21% to 32% depends on H2 percentage used. Results from the density shows that the higher the H2 gas concentration, the smaller the density changes. Significant change in porosity of the sample before and after reduction was observed. Size of pore after reduction determined by H2 concentration used during reduction where the higher the H2 concentration resulted in large pore size.
Tungsten Carbide-Nickel (WC-Ni) Coating as Potential Wear and Corrosion Protection for Metal
Authors: Ning Alex Shee Yin , Zakiah Kamdi , Ainun Rahmahwati Ainuddin , Hussin Rosniza , Aida Ibrahim Siti
Published: September 2020

Tungsten carbide-based composite / cermet coatings have been deposited to improve metal properties such as hardness, corrosion resistance, and wear resistance. In this study, the evaluation of two deposition methods, which are high velocity oxy-fuel (HVOF) and electrodeposition (ED) is done to compare their performance as metal protection from corrosion and wear. The HVOF powder was deposited using oxygen and natural compress gas and sprayed at 700 m/s. Watt’s Bath was used as an electrolyte in ED coating method. The corrosion and wear behavior was assessed using electrochemical and weight loss methods, respectively. The HVOF coating shows more positive corrosion potential, Ecorr at -0.75 V showing higher corrosion resistance than the ED coating at 1.15 V. The wear rate for HVOF coating is lower than the ED coating at 0.0001 g/m compared to ED coating at 0.0002 g/m. In can be concluded that the HVOF coating has higher wear and corrosion resistance compared to ED coating.
Crystallization Kinetics and Fragility of Al-Based Amorphous Alloy
Authors: Wahid Mohd Fitri Mohamad , Laws Kevin J. , Ferry Michael
Published: September 2020

Crystallization among amorphous alloy is a crucial study since it generally affects it properties, which may detrimental or beneficial, depending in the intended application of the materials. Controlling crystallization is crucial for obtaining the desired properties. The crystallization study was performed using differential scanning calorimeter (DSC). Samples were heated at heating rate between 20 and 40 K·min-1. Structural evolution during crystallization was studied under X-ray diffraction (XRD). Apparent activation energy for each temperature characteristics was determined using Kissinger’s equation. Local Avrami exponent was investigated using modified Johnson-Mehl-Avrami-Kolgomorov equation. Liquid fragility, which indicates the strength of the glass formation, was predicted using temperature characteristics instead of its viscosity. It was found that upon crystallization both as-cast samples crystallize to cubic-Al, Al2CuMg and Al2Cu and Al3Ni. Alloy with composition of (Al75Cu17Mg8)95Ni5 shows superior activation energy at every temperature characteristics than alloy with composition of Al75Cu10Mg8Ni7. Local Avrami exponent and local activation energy for (Al75Cu17Mg8)95Ni5 show high values at the beginning and at the end of crystallization process. From liquid fragility, it was predicted that the samples are stronger glass former than previous studied Al-amorphous alloys.
Influence of Heating Temperature on Structure, Morphology and Electrochemical Performance of LiV3O8 Cathode for Lithium-Ion Batteries Application
Authors: Ishak Mohamad Izha , Ahmad Khairel Rafezi , Osman Rozana Aina Maulat , Idris Mohd Sobri
Published: September 2020

LiV3O8 layered structure was successfully synthesized by a conventional solid-state approach and subsequent heat-treated at 400, 450, 500 and 550 oC. The samples were characterized by XRD, SEM, TEM, BET. Electrochemical performance of LiV3O8 was investigated by cyclic voltammetry (CV) and galvanostatic charge-discharge. The results showed that high purity of LiV3O8 with layered structure was formed. The morphology of the samples were mixed between nanorods and nanosheets structure. For electrochemical performance, results showed that LiV3O8 heat-treated at 500 oC performed a highest charge and discharge capacity of 212 and 172 mAh g-1, respectively. From electrochemical performance results made them a good candidate for cathode material for lithium-ion batteries application.
Tailoring of Optical and Physical Properties of ZnO Films by Co-Doping Concentration
Authors: Ainun Rahmahwati Ainuddin , Ismail Siti Sarah Mohd , Yusuf N.A.
Published: September 2020

The modification and tailoring characteristic of nanostructured materials are of great interest due to controllable and unusual inherent properties in such materials. Cobalt-doped zinc oxide (Co:ZnO) thin films were prepared using the sol-gel technique with the spin coating method. The optical and physical properties of Co:ZnO films were tailored by the adjustment of Co concentration, which was realised by varying the ratio. The morphology and structure properties were characterised, and the effects of Co doping and post-annealing were investigated. Similar with undoped ZnO, the synthesised Co:ZnO films have a hexagonal wurtzite structure with the crystallinity deteriorated, and present high visible transparency with the absorption edge redshifted. Debye–Scherrer analysis of XRD pattern reveals an increase of the crystallite size with doping concentration. The bandgap, calculated using a Tauc Plot method, reveals a decrease in the absorption onset with an increase in the doping level.
Application of Octadecylamine-Based Adsorbent on Carbon Dioxide Capture
Authors: Abu Tahari Maratun Najiha , Lahuri Azizul Hakim , Ghazali Zaitun , Samidin Salma , Sulhadi Siti Sarahah , Dzakaria Norliza , Yarmo Mohd Ambar
Published: September 2020

Porous surface of silica gel (SG) have been modified with alkyl fatty amine compounds (octadecylamine, ODA) via wet impregnation process. The ODA-based adsorbents were physically characterized by XRD. The presence of crystalline peaks on ODA/SG diffractograms were ascertained the well-dispersion of ODA on the SG surface. XRD analysis displayed the increasing intensity of crystalline ODA with higher percent amine loaded and shifting of the several crystalline peaks of ODA verified the interaction of SG600-ODA. Capacity of CO2 capture by prepared solid adsorbents were evaluated using CO2 adsorption-desorption isotherms. This study shows that increasing percentage of ODA were improved the amount of CO2 uptake by following this trend: 35ODA/SG > 25ODA/SG > 15ODA/SG > SG > 5ODA/SG. However, promotion of 5 wt.% ODA unabled to enhance the capacity of CO2 captured due to pore blockage and reduction in SG pore surface, thus hindered the physisorption between CO2 and SG.
Phase Evolution during Carbothermal Reduction of Langkawi Ilmenite Ore at Different Reaction Times
Authors: Yunos Nur Farhana Mohd , Chong Jian Hao , Mohammed Ahmed Indris , Idris Muhammad Asri
Published: September 2020

In this research, the carbothermal reduction of Langkawi ilmenite ore, FeTiO3 had been conducted by using coke as carbon reductant. All samples were grinded into size of ≤ 63 µm and pelletized using 2.5 g mixture of ilmenite ore with coke based on C/O molar ratio of 1:3 (carbon to reducible oxygen). The carbothermal reduction was conducted in a horizontal tube furnace using 0.1 L/min of argon gas flow at temperature of 1200°C. The ultimate and proximate analysis of carbon reductant was investigated using carbon, hydrogen, oxygen, nitrogen and sulfur (CHONS) analyzer. The phase evolutions and chemical composition analysis was conducted using X-ray diffraction (XRD) and X-ray fluorescence (XRF) for raw ilmenite and reduced ilmenite with coke, respectively. The reduction time was set with 2, 3 and 4 hours to understand the phase evolutions. It was found that Langkawi ilmenite ore contained mainly higher TiO2 and hematite, Fe2O3 where the phases of FeTiO3 and titanomagnetite, (Fe2TiO4-Fe3O4) were detected using XRD. The phase of FeTiO3 evolved into the production of Fe, FeO, TiC, TiO2 and Fe3C when increased the reduction time from 2 to 4 hours. The amount of Fe2O3 production was decreased from 59.16 to 47.02 wt%, while higher value of TiO2 was obtained, increasing from 25.2 to 29.1 wt% due to the reduction of TiO2 to Ti3O5 as the reduction time increased. TiC content is also detected when the reduction time increased by reducing TiCxOy into TiC.
Synthesis of Visible-Light Active Monoclinic WO3 by Thermal Oxidation of Tungsten Powder for Photoreduction of Cr(VI)
Authors: Bashirom Nurulhuda , Lee Qiao Ling
Published: September 2020

In this paper, visible-light-active monoclinic WO3 powders were synthesized by thermal oxidation of W powders at 200 – 1000 °C in air atmosphere. Morphology and crystal structure of annealed W powders were characterized by Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD), respectively. Based on SEM and XRD results, a spherical orthorhombic-W3O8 obtained at 200 °C was transformed into a dendritic monoclinic WO2 + tetragonal WO3 + monoclinic WO3 structures at 400 °C accompanied by a color transition from grey into green. At 600 °C, yellow monoclinic WO3 + monoclinic WO2.96 powder was produced that ascribed to oxygen vacancies. Photocatalytic activity of annealed W powders demonstrated 70.7% Cr (VI) removal after 150 min on sample annealed at 1000 °C. This ascribed to high photoactivity of monoclinic WO3. Nevertheless, the dendritic monoclinic WO2 + tetragonal WO3 + monoclinic WO3 obtained at 400 °C exhibited the lowest Cr (VI) photoreduction i.e. 45.2% implies less photoactive monoclinic WO2 and sluggish electron transport at oxide-oxide interfaces.
Iron Oxide Catalyst for Oxidative Desulfurization of Model Diesel Fuel
Authors: Mohd Nazmi Nor Atiq Syakila , Wan Abdullah Wan Nazwanie , Adam Farook , Wan Mokhtar Wan Nur Aini , Yahaya Noorfatimah , Mohd Shukri Nurasmat
Published: September 2020

— The catalytic oxidative desulfurization (Cat-ODS) process has been introduced as a new technology to achieve ultra-low sulphur levels in diesel fuels. In this study, the performance of the alumina supported iron oxide based catalysts doped with cobalt, synthesized via wet impregnation method on the Cat-ODS of the model diesel with the total sulphur 500ppm was investigated using tert-butyl hydroperoxide (TBHP) as an oxidizing agent and N,N-dimethylformamide as an extraction solvent. A series of dopant was being screened. Co/Fe-Al2O3 (10:90) and Co/Fe-Al2O3 (20:80) prepared at 400°C. Overall, the catalytic activity decreased as dopant ratio increased. Catalyst with 10 wt% of Co was successfully removed 96% of thiophene, 100% of DBT and 92% of 4,6-DMDBT in model diesel. Further investigation, potential catalyst that calcined at 400°C contributed higher sulphur removal compared to the catalyst calcined at 500°C. X-ray diffraction analysis (XRD) result showed that Co/Fe-Al2O3 (10:90) prepared at 400°C was amorphous, while micrograph of the field emission scanning electron microscopy (FESEM) illustrated an inhomogeneous distribution of various particle sizes. The energy dispersive X-ray analysis (EDX) result have confirmed the presence of Fe and Co in all of the prepared catalyst.
Estimating Suitable Starch Extraction from Mango Seeds Using Analytical Hierarchy Process (AHP) Method
Authors: Shahrim Nur'Aishah Ahmad , Sariffudin Norshahida , Zaki Hafizah Hanim Mohd , Azhar Ahmad Zahirani Ahmad
Published: September 2020

The mango seed was extracted to starch via distillation, alkaline, sedimentation and centrifugation methods. Based on the analysis, different starch extraction methods resulted in different proximate composition, physicochemical, morphological, structural, functional and thermal properties of starch. As such, it is necessary to choose a suitable starch extraction method to fabricate starch-based film for packaging application. Therefore, in this study, Analytic Hierarchy Process (AHP) method was applied for performing the decision-making process. Based on the AHP method, it was found that, the best alternative for starch-based films is distillation method.
Methylene Blue Removal Using Foxtail Palm Fruits as Potential Activated Carbon
Authors: Nik Yusoff Nik Raihan , Mohamed Jefry Syafiqa Jauna , Lai Yin Teng , Abdul Halim Nurul Syazana , Subki Noor Syuhadah
Published: September 2020

Textile industry is commonly use dyes in colouring process which become the major dye wastewater source that leads to serious pollution in the environment. The disposed dyes can lead to serious harm to the water users and life in the aquatic because of the dye properties. Hence, the dye adsorption by activated carbon prepared from foxtail palm fruit was studied. The objectives of this study were: 1) to prepare activated carbon from foxtail fruit palm and 2) to study the effect of contact time, adsorbent dosage and initial concentration of dye usage toward the efficiency of the prepared activated carbon. Nitric acid was used as activating agent in this experiment, with impregnation time of overnight and 500 °C of 2.5 hours carbonization. The adsorption capability of foxtail fruit palm activated carbon as activated carbon was determined with the use of a dye called methylene blue. The results showed that 5 g of activated carbon was used to reduce 97.1% of 2 mg/L methylene blue with 150 minutes contact time. This result aligns with the SEM result which indicated that the produce activated carbon is rich with well-developed and irregular size of pores ranging between 1.585 μm to 7.556 μm. This study indicates that activated carbon from foxtail palm fruits could be utilized as an alternative activated carbon to treat dye wastewater.
Preparation and Characterization of Kenaf and Oil Palm Nanocellulose by Acid Hydrolysis Method
Authors: Mocktar Nurfarah Aini , Razab Mohammad Khairul Azhar Abdul , Mohamed Noor An'amt , Abdullah Nor Hakimin
Published: September 2020

Acid hydrolysis method become one of the attention among researcher to produce high degree nanocellulose. Integration of sonication process was used to stir and mix particles in an element for different stages. This paper revealed the surface morphology and crystallinity index of two organic plant that were kenaf and oil palm nanocellulose. Characterization of the nanocellulose were identified by 2 techniques; (1) field emission scanning electron microscope (FESEM) that provides surface morphology and elemental information of the element, (2) x-ray diffraction (XRD) for phase identification of materials crystallinity. The result showed that the properties of nanocellulose increase after sonication method have been integrated.
Preparation of Nanosilica Powder Using Rice Husk via Precipitation Method
Authors: Daud Farah Diana Mohd , Azmy Nur Aishah M. , Mahmud Mudrikah Sofia , Sariffudin Norshahida , Zaki Hafizah Hanim Mohd
Published: September 2020

Silica in nanoscale has various superior properties which leads to a wide range of applications. Most researches used and metal alkoxides as the sources but very few researches attempted at preparing nanosilica powder from the agricultural waste which environmental friendly and inexpensive. This research is presented as the studies of optimization of parameters involved during preparation, aimed to improve the purity of silica produced. In this work, rice husk ash (RHA) precursor was subjected to precipitation method in order to produce nanosilica powder. Acid leaching and thermal treatment were done as a pre-synthesis process. The process parameters that have been studied were the refluxed NaOH concentration, heating time, and temperature, in which the properties were then evaluated during characterization process. The results from X-Ray Flourescence (XRF) confirmed that it is possible to extract 100% purity of silica from RHA treated by the combination of thermal treatment, acid leaching, refluxed with 2.5 M of NaOH and heated at 50°C for 48 hours. X-Ray Diffraction (XRD) illustrated that the produced silica is in amorphous state. Meanwhile, the mean particle size of the spherical shape of silica obtained ranging from 44.7 nm to 1.23 μm. Therefore, the best mean particle size obtained was by using the sample refluxed with 2.5 M NaOH and heated at 50°C for 48 hours, which were confirmed by Scanning Electron Microscope (SEM) and Field Emission Scanning Electron Microscope (FESEM). These findings on the optimum parameters indicate the successful production of highest purity of nanosilica powder with nanoscaled particle size.
Preparation of TiO2 Decorated Eggshell Membrane for Photocatalytic Dye Degradation
Authors: Samsuddin Ezatul Kamaliah , Aida Ibrahim Siti , Noraini Marsi , Rus Anika Zafiah Mohd
Published: September 2020

Pristine ESM was impregnated with TiO2 using the wet chemical method and subsequently calcined at 700 °C. All prepared samples were characterized using Field Emission Scanning Electron Microscope (FESEM), X-ray Diffraction (XRD) and UV-visible Spectrometer. FESEM images indicate the presence of a fibrous network that introduces useful adsorptive and photocatalytic properties for organic pollutants removal from water. The XRD result indicated that the TiO2 nano-composite contained only anatase and rutile phase. Photocatalytic results revealed that the photocatalytic activity of TiO2 increased under visible light irradiation in the presence of the carbonized eggshell membrane. It is found that TiO2-CESM produced the highest photocatalytic degradation of 93 % within 5 hours of irradiation time.
Characterization of GO:I-131 for Radioactive Clinical Waste Water Management in Nuclear Medicine
Authors: Razab Mohammad Khairul Azhar Abdul , Mansor Mohd Syahir , Mohamed Noor An'amt , Latif Nur Fatin Fariha Abd , Rozi Suhanis Mohamad , Jaafar Khairul Nizam , Jamaludin Farakhdina
Published: September 2020

Iodine-131 (I-131) mostly used in nuclear medicine for radioiodine ablation (RAI) therapy and hyperthyroid treatment. Patient was orally ingested I-131 and warded within 3 to 4 days for RAI therapy, whereas outpatient for hyperthyroid treatment. Radioactive waste from patient’s body such as urine and feces were eliminated from the ward into delay tank. Delay tank is an underground system to reduce radioactivity of contaminated I-131 clinical waste water at certain level before will be discharged into ordinary sewage system. Delay tank indirectly restricted the number of patient admission due to its periodical clearance and small volume size. Thus, a new technique to extract I-131 radionuclide with contaminated mixtures in solid form from the delay tank has been proposed as an alternative for clinical waste water management in nuclear medicine. Radioactive clinical waste water samples from delay tank were mixed with Graphene Oxide (GO) with varies in concentrations before filtered using micro pore filter paper. After 15 – 30 minutes, the radioactivity of the water residue left beneath the filter paper were counted using well counter. The measurements were repeated on fourth, eighth, twelfth and sixteenth days, which is significant to the natural decay of I-131 radionuclide. The water residue radioactivity decreases over the concentration of GO throughout the experiment. The mixtures of GO:I-131 (sediment formed on the filter paper) were analyzed using Field Emission Scanning Electron Microscopy (FESEM) and Energy Dispersive X-rays (EDX) for morphology and elemental analysis. FESEM image revealed the maximum GO concentration produced high agglomeration morphology. EDX shows I-131 and other elements were attracted to GO layered sheets. The results showed that the GO had high sorption capacities in the removal of radionuclides, which was attributed to the large number of oxygen-containing functional groups on the surface or edge sites.
Oxidation Kinetics of Fe-Ni-Cr Alloy at 900 °C
Authors: Parimin Noraziana , Hamzah Esah
Published: September 2020

The study of isothermal oxidation of Fe-Ni-Cr alloy was done at 900 °C for 500 hours. The effect of oxidation kinetics and oxide growth behavior on Fe-Ni-Cr alloy were investigated on heat-treated Fe-Ni-Cr alloy to understand the oxidation mechanism on different grain size of alloy. The grain size of Fe-Ni-Cr alloy was varying through heat treatment process at three different temperatures, namely 1000 °C, 1100 °C and 1200 °C for 3 hours soaking time followed by water quench. The heat-treated Fe-Ni-Cr alloy was experienced discontinuous isothermal oxidation test at 900 °C up to 500 hours exposure. The oxidation kinetics plot was calculated based on the weight change per surface area over time. The oxide surface morphology was characterized by using scanning electron microscope (SEM) equipped with energy dispersive x-ray (EDX) spectrometer. The heat treatment process recorded an increasing grain size alloy as the heat treatment temperature increase. 8H10 sample indicate the fine grain size, whereas 8H12 sample indicate the coarse grain size. The oxidation kinetics of all samples exhibit the weight gain pattern with fine grain 8H10 sample recorded the lowest weight gain compared to 8H11 and 8H12 samples. All samples were obeyed parabolic rate law indicating the oxide growth rate followed a diffusion-controlled mechanism. The oxide surface morphology of 8H10 sample displayed a continuous oxide scales with formation of grain boundary oxide along the grain boundary area. Similar oxide structure formed on 8H11 and 8H12 samples, except for the formation of crack on the grain boundary oxide on both samples. In addition, 8H12 sample also formed a porous oxide structure.
Preparation and Characterization of Calcium Hydroxyphosphate (Hydroxyapatite) from Tilapia Fish Bones and Scales via Calcination Method
Authors: Abdullah Nor Hakimin , Mohamed Noor An'amt , Mat Rasat Mohd Sukhairi , Mamat Sarizam , Mohamed Mazlan , Mohd Shohaimi Norshahidatul Akmar , Ab Halim Ahmad Zamani , Mohd Shukri Nurasmat , Razab Mohammad Khairul Azhar Abdul , Mohd Amin Mohamad Faiz
Published: September 2020

Calcium hydroxyphosphate (hydroxyapatite) is a calcium phosphate that is widely used in biomedical application. Hydroxyapatite is an excellent component for bone substitutes for their chemical and structural similarity to natural bone component. In this research, hydroxyapatite was synthesized from tilapia fish bones and scales using calcination method with 3 different temperatures namely 1000 °C, 900 °C and 800 °C. The obtained hydroxyapatite powder was characterized using several techniques such as Fourier-Transform infrared spectroscopy Attenuated total reflection (FTIR-ATR), scanning electron microscope (SEM), proximate analysis and X-ray diffraction (XRD). The results indicated that temperature 1000 °C has the highest weight loss with 21.825 g compared to the temperature 800 °C and 900 °C. From FTIR-ATR analysis, the presence of characteristic peaks for hydroxyl group, phosphate groups and water molecule indicated that the powder were hydroxyapatite. SEM results showed that increasing temperature had led to more dense structure. The hydroxyapatite powder were further analysed for their proximate analysis. The results proved that the highest contents of ash, fat, moisture and crude protein were observed at 1000 °C as compared to 900 °C and 800 °C. Based on this study, it revealed that produced pure hydroxyapatite from natural resources could be a potential candidate for food industry as protein enhancer.
Tensile Strength on Seven Type of Fruits Skin Fiber Thermoplastic Poyurethane (TPU)
Authors: Ahad Nor Azwin , Ju Ann Yeo , Norozi Nurul Atirah , Azman Ain Amirah
Published: September 2020

Natural fibers of trees, fruit skins and so on are considered as recyclable and are used as filler materials in polymer composites. For decades, natural fibers have become the attention of researchers as an alternative to commercial, synthetic and costly fibers. Therefore, this study has used 7 types of natural fibers from local fruit waste parts in Malaysia, as fillers in TPU. This composite was produced via melt mixing technique, with different filler loading from 5wt% to 20wt%. Different types of natural fiber and its loading, showed different mechanical properties which resulted through tensile strength and elongation at break. Also, it is found that each of these natural fibers gives maximum tensile strength to the optimum loading between 5wt% and 10wt%. The composite with pineapple fiber is the composite with the highest tensile strength value at 5wt% filler load, as well as the most elastic composite with the highest elongation at break percentages.
Synthesis and Characterization of 50S8P Bioglass through Sol Gel Method
Authors: Syed Salim Sharifah Aishah , Mohamad Hasmaliza , Mohd Noor Siti Noor Fazliah
Published: September 2020

Bioactive glasses (BG) were applied in bone and dental applications as well as in tissue engineering. In this studies, a new bioglass 50S8P (50% SiO2, 22% CaO, 20% Na2O and 8% P2O5) with different aging time (3, 7, 10 and 15 days) was prepared by sol-gel method. These synthesized glasses were analyzed using X- ray powder diffraction (XRD), Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The bioactivity of all BG is evaluated by incubating the BG powder in Hank's Balanced Salt Solution (HBSS) for 7, 14 and 21 days. Thermal analyses indicated the compositions can be stabilized at 700°C. XRD confirmed the primary crystalline phase was Na4Ca4Si6O18. Formation of silica network is established with the existence of functional group Si-O-Si (tetrahedral), confirmed with FTIR analyses. In vitro test confirm the apatite formation on the BG surface with characteristic of carbonate group (C-O) and P-O band noticed from FTIR and morphology of apatite formation on BG surface was observe using SEM
Chitosan/Polyethylene Oxide (PEO) Filled Carbonized Wood Fiber Conductive Composite Film
Authors: Mohd Pisal Mohd Hanif , Abd Jalil Jalilah , Anisah Mohd Fadzil Hanim , Tilagavathy Arumugam
Published: September 2020

Biopolymer-based conductive polymer composites (CPCs) would open up various possibilities in biomedical applications owing to ease of processing, renewable resource and environmentally friendly. However, low mechanical properties are a major issue for their applications. In this study, the investigated the conductivity of chitosan/ PEO blend films filled with carbonized wood fiber (CWF) prepared by solution casting. The effect of CWF was also investigated on tensile properties and their morphological surfaces. The tensile results from different ratios of chitosan/PEO blend films without CWF show that the tensile strength and modulus increased with the increase of chitosan content and chitosan/PEO blend film with 70/30 ratio exhibited the best combination of tensile strength and flexibility. However, a reduction of tensile strength was observed when CWF amount was increased while the modulus of the tensile shows an increment. The film also exhibited higher electrical conductivity as compared to low chitosan ratio. The addition of CWF greatly enhanced the conductivity three-fold from 10-10 to 10-6 S/cm. The electrical conductivity continued to increase with the increase of CWF up to 30wt%. The surface morphology by Scanning Electron Microscopy (SEM) exhibits the absence of phase separation for the blends indicating good miscibility between the PEO and chitosan. Incorporation of CWF into the blend films at 5wt% showed agglomeration. However, the increase of CWF created larger agglomerations that formed conductive pathways resulting in improved conductivity. FTIR analysis suggested that intermolecular interactions occurred between chitosan and PEO while CWF interacts more with the protons of PEO.