Conference Publications
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PublicationComparative study on mechanisms of gases release from Ca-alginate beads( 2024)Calcium alginate (Ca-alginate) beads have attracted considerable attention as carriers for the controlled release of volatile compounds due to their biocompatibility and tunable properties. This study aimed to compare the release of ethylene and carbon dioxide gas from Ca-alginate beads. Ca-alginate beads were prepared from a sodium alginate solution containing ethephon and calcium carbonate as the gas-forming agent. The resulting solution was then extruded into a calcium chloride solution. The gas release behavior was studied by monitoring the concentration of released gases over time using gas detectors. Extrusion tip diameter, alginate concentration and gas-releasing agent concentration were systematically varied to assess their effect on the gas release rate. The results indicated distinct release patterns for ethylene and carbon dioxide gas. Ethylene gas exhibited a relatively slower and sustained release, while carbon dioxide gas exhibited a more rapid release. Moreover, the bead size influenced the gas release, with larger beads displaying faster release rates for ethylene and carbon dioxide gas. The concentration of alginate also played a role in modulating the release kinetics, with higher alginate concentration resulting in slower gas release. The findings have implications for designing and optimizing Ca-alginate-based systems for agricultural applications, including plant hormone delivery and modified atmosphere packaging.
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PublicationOptimization of chlorophenols adsorption using OPEFB biosorbent( 2022-11-18)Palm oil industry have long been one of the most important economic drivers in the country. However, the abundance of wastes generated such as oil palm empty fruit bunch (OPEFB) and palm oil mill effluent (POME) have resulted in serious environmental issues that necessitate immediate response. This work investigates the optimization of biosorption of chlorophenols, which are commonly found in POME, using treated OPEFB biosorbent. The surface of biosorbent was modified by physical or chemical treatment. The biosorption capacity for 2,3-dichlorophenol (2,3-DCP) are higher than that of 2-chlorophenol (2-CP). Therefore, 2,3-DCP was further examined in the optimization study by Full 2k factorial design and Central Composite Design (CCD). A full 25-1 factorial design with five factors and two levels was used to screen the significant factors that influenced the biosorption process. These results were applied in the optimization using CCD with three factors (initial 2,3-DCP concentration, pH of solution and OPEFB biosorbent dosage). It is found the optimum conditions for 2,3-DCP biosorption were 200?ppm initial concentration, pH 5 and 0.15?g dosage. The maximum biosorption capacity was 13.65?mg/g. Langmuir biosorption isotherm best described the biosorption of 2,3-DCP onto OPEFB biosorbent at different initial concentrations of 2,3-DCP solution. Pseudo-second order was found to best fit the biosorption system by OPEFB biosorbent. Therefore, it is worth considering the potential use of OPEFB biomass as a biosorbent in the application of the treatment of toxic pollutants.
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PublicationPreliminary investigation on the correlation between mechanical properties and conductivity of low-density polyethylene/carbon black (LDPE/CB) conductive polymer composite (CPC)( 2022-01-24)The insulating nature of a polymer can be changed to electrically conductive by incorporating conductive fillers within the polymer matrix to form a conductive polymer composite (CPC). One of the potential application of CPCs are in the area of flexible electronic interconnect application. Nevertheless, the correlation between the electrical conductivity and mechanical properties of CPCs such as tensile was found to be limited. Therefore, this paper is aimed to report the preliminary investigation on the correlation between conductivity and mechanical properties of a low-density polyethylene (LDPE) incorporation with conductive filler which is carbon black (CB. It was observed that the tensile strength was decreased by up to 29.4% and the elongation of break was decreased by up to 90.6% at higher CB loading compared to pure LDPE. Nonetheless, the modulus of elasticity and the electrical conductivity of the composites were increased by up to 150.5% and 16.4% at higher CB loading respectively. Moreover, it was found that the effect of CB additions on the tensile modulus was greater compared to the conductivity of the CPCs.
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