Materials Science Forum Vol. 1056

Abstract: The physical (density and moisture content) and chemical properties of the oil palm trunk (OPT) were examined. The effect of different densities (500, 600, and 700 kgm^-3) and different percentages of urea-formaldehyde (UF) resin content (8, 10, and 12%) on the single layer at the different portions of OPT particleboard were evaluated for mechanical and dimensional stability. The results showed that the bottom portion and near bark had a positive result on density and moisture content. Lignin, holocellulose, and alpha-cellulose of the OPT showed the highest content at the bottom portion. The density was found to effect all the board properties significantly at p < 0.05 on the modulus of elasticity (MOE), modulus of rupture (MOR), internal bond (IB), thickness swelling (TS), and water absorption (WA) of the particleboards. For the resin content, all the board properties were effected except for the water absorption. The particleboards produced, from 700 kgm^-3 densities and 10% resin content, met the minimum requirement for the particleboard (Type 18) stipulated in the Japanese Industrial Standard (JIS A 5908). The particleboard manufacturing from OPT particles as the replacement for wood is very promising.

Abstract: Retracted article: The technique of using small diameter whole-culm and split bamboo has been often suggested as an alternative method for concrete strengthening. Bamboo is widely available in tropical and sub-tropical locations, while the quest for a new sustainable alternative is a new and recent trend in the construction industry. Using bamboo in reinforced concrete is discussed in this paper and it is analysed as a structural and environmental alternative to steel reinforced concrete. Reinforced concrete is widely used in many countries where bamboo reinforced concrete might be used as a design alternative to determine the life cycle of reinforced concrete. However, bamboo was extraordinary material. Therefore, it is used in reinforced concrete due to significant durability and reduced stiffness problem, which positively impacts the environment. Hence, this paper discusses a review on the structural performance of bamboo reinforced concrete based on previous research.

Abstract: Cement, sand, aggregate, water and reinforcing bar are the materials in reinforced concrete, while a mixture without reinforcing bar is known as concrete. Concrete and reinforced concrete is the most widely used building material in the construction industry. Brittleness occurs when concrete is unable to withstand tensile loading, resulting in brittle failure. Moreover, fibre has the potential to improve the tensile strength of concrete. Due to this fact, steel fibre reinforced concrete (SFRC) exhibits superior resistance to cracking. It intends to increase the durability and decrease the crack deformation characteristics. This review article discusses the theoretical aspects of SFRC. Numerous references from both early and contemporary writers are included to help tie the subject together chronologically. This historical analysis aims to provide context for what is currently known about SFRC rather than to provide historical reporting. Hence, this paper discusses a review on the strengthening of reinforced concrete with steel fibre based on previous research before this.

Abstract: Waste can be categorized as organic waste and chemical waste. Organic waste generated from agriculture industry had been proofed to be use in concrete production to enhance the concrete performance. The main purpose of adding the fiber in concrete structure is to control cracking due to plastic shrinkage and to drying shrinkage. Besides, it can also reduce the permeability of concrete, thus, reduce the bleeding of water. Some types of fibers produce greater impact, abrasion, and shatter resistance in concrete. Therefore, this paper reviewed the mechanical properties of concrete containing oil palm and coconut fiber as an additional material in concrete. Coconut fiber length is longer than oil palm fiber. Therefore, in comparison, by adding coconut fiber in concrete up to 5% may reduce the flexural and tensile strength of the concrete due to agglomerate effect of the fiber. In contrast, for oil palm fiber, beyond 5% of addition in concrete will improve the flexural and tensile strength of the concrete due to the length effect of the fiber. By discussing both organic fiber as an additional material to strengthen the concrete, it can contribute to the body of knowledge in term of reducing cracks in concrete. Besides, it will give a better understanding to readers regarding the function of the materials in concrete.

Abstract: The need to recycle and develop valuable materials from waste, and use them in various applications have become increasingly important in recent decades. Printer toner waste is one of the most polluting electronic waste due to the toxic nature of the material content in it. Despite the toxicity of the material in the toner powder, it contains iron oxide that can be extracted and recycled to make a beneficial material. Therefore, this study aims to investigate a facile and effective method to extract iron oxide from printer toner waste powder. Magnetic separation and oxidation processes were used as a method for extraction and phase conversion. The structural transformation was investigated using X-ray diffraction, microstructural observation using scanning electron microscope whereas static magnetic characteristics were investigates using vibrating sample magnetometer. The results from XRD spectra show that printer toner wastes that have been subjected to magnetic separation process and chemical treatment, even without any heat treatment process, have produced a single phase magnetite. Through the process of heat treatment on the sample, phase transformation from magnetite to hematite occurs, in which a single phase of hematite is obtained at a temperature of 1400 °C. The saturation magnetization of the sample also showed a reduction where the sample before undergoing the heat treatment process had a saturated magnetization value of 18.81 emu/g. Meanwhile, after heat treatment, the saturation magnetization value decreased to 0.42 emu/g. These results are in line with the phase transformation shown where magnetite has high ferrimagnetic characteristics, whereas hematite is basically antiferromagnetic at room temperature. However, the saturation magnetization that has been obtained in hematite shows a little difference to that of commercially sold hematite. This proves that iron oxide extracted from printer toner waste has a high potential as an alternative to existing commercial iron oxide in producing high performance magnetic materials.

Abstract: Malaysia is known as one of the major petroleum producers in the Asia-Pacific region. Petroliam Nasional Berhad (PETRONAS) in 2018 stated that the average daily production was over 1.7 million barrels of oil equivalent while the remaining reserves were estimated at more than 5 billion barrels of oil equivalent within more than 400 oilfields. With the growing demand for petroleum-based products, significant contaminated scales and sludge are generated each year from the petroleum industry. During production, the extracted fluids from the oil reservoir tend to carry along the Technologically-Enhanced Naturally Occurring Radioactive Materials (TENORM) of the ²³⁸U and ²³²Th decay chains from the Earth’s crust. TENORM in the petroleum sludge will results in radionuclides’ precipitation with silicates and carbonates, thus lowering the amount of oil extracted. There is a need for further information regarding the elemental composition (metal and nonmetal) and the surface morphology. Such information will guide the choice for useful partitioning of heavy metals between solid and gaseous products and provide a basis for comparing product characteristics with the parent material. Thus, this paper presents a comprehensive analysis of petroleum sludge’s physical and chemical properties and its treatment and application. Profound evaluation of the extent of sludge treatment before disposal could be done and can significantly impact refinery and petrochemical industries.

Abstract: A comparative study of the Carbon Quantum Dots (CQDs) based composites photocatalyst for water purification was carried out. New finding of CQDs and TiO₂ have demonstrated significant advantage since it provides environmentally friendly for photocatalytic degradation of methyl orange (MO) dye. CQDS and TiO₂ were prepared by using hydrothermal method. The CQDs and CQDS/TiO₂ were fully characterized by using transmission electron microscope (TEM) to identify the size range and shape that involve in the adsorption process. The synthesized CQDs and CQDs/TiO₂ had small semi spherical morphology with 5 nm in size. The result of photocatalytic activity revealed that there is photocatalytic degradation of MO in the presence of only pure CQDs and CQDs/TiO₂ composites which the value of concentration decreased against time. CQDs/TiO₂ exhibited higher photocatalytic activity, which indicated that both CQDs and TiO₂ played important roles for the high photocatalytic activity under visible light irradiation.

Abstract: In present study, a simple chemical method for the synthesis of silver-reduced graphene oxide (AG/RGO) nanocomposite was reported. The objective is to evaluate the performance of AG/RGO in photocatalytic degradation activity of methyl orange (MO) under artificial visible light source. The synthesized catalyst was then characterized using field emissions scanning electron microscope with energy dispersive X-Ray spectroscope (FESEM-EDX), photoluminescence spectroscopy (PL) and UV-visible spectroscope (UV-VIS) to determine the morphology, physical and chemical composition of the photocatalyst. The characterization results show the synthesized catalyst possess nanometre dimension silver nanoparticles (AgNPs) were deposited on reduced graphene oxide sheets. The photocatalytic activity of 0.3 g AG/RGO obtained through the degradation of 5 mg/l MO is 93.74% with a degradation rate of 3.1 × 10^-2 min^-1.

Abstract: Research on polymers has grown exponentially in the purpose of oil spill removal from the water surface. It is very important to take immediate action to remove the oil from the water surface to reduce worldwide oil pollution. Materials with high porosity and mostly, superhydrophobic and oleophilic natures are the best candidates for this purpose. In this research, the electrospinning method was used to synthesize the polystyrene (PS), polysulfone (PSF), and polyvinylidene fluoride (PVDF) for the application of oil-spill removal. Different concentrations were used to produce electrospun fiber using N, N-Dimethylformamide (DMF). Contact angle (CA) measurement was applied to justify the hydrophobicity of all the polymers. Based on the CA results, only one sample, 24%concentrations of polystyrene (PS-5) showed the highest water contact angle (WCA) and the value was above 150°. This means PS-5 is superhydrophobic. ASTM F726-12 standard and low viscous motor oil were used for the oil sorption test. Moreover, the oil sorption results were compared within all the polymers to identify the best polymer, and solvent concentration that can absorb oil the most. The highest oil absorption efficiency is 20.99g/g using 24% concentrations of PS (PS-5) electrospun fiber.

Abstract: An inert ceramic ball was prepared by using three kind of raw materials i.e. Selendang clay, silica sand, feldspar and distilled water. Selendang clay, silica sand, feldspar and distilled water were pre-mixed manually and compounded using a beaker. Universal testing machine (UTM) was used to test mechanical strength. Electron scanning microscope (SEM-EDX) was used for the study morphological feature and element mapping in the ceramic balls. X-ray powder diffraction (XRD) was used to determine the phase of crystalline material. The optimum sintering temperature was 1300 °C23 and got the strength of 238.8 kgf.