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PublicationSurface modification of waste tire dust under pre-irradiation emulsion grafting technique(Universiti Malaysia Perlis (UniMAP), 2022)In recent years, the rate of waste tire disposal has increased dramatically, jeopardizing world ecological equilibrium. The utilization of this waste in polymer composite as a sustainable and low-cost filler is one of the possible solutions. However, the compatibility of waste tire dust (WTD) with most matrices is limited which results in the degradation of the composite's mechanical properties. The goal of this study was to enhance the interfacial bonding at the rubber-matrix interface. This was done by utilizing the carbonyl group of tripropylene glycol diacrylate (TPGDA) using pre-irradiation emulsion grafting techniques to develop grafted WTD (G-WTD) which can generate a strong chemical bond between the rubber and the polymer matrix. The WTD was initially modified via radiation-induced grafting (RIG) techniques with a TPGDA emulsion. The effect of grafting parameters on the grafting yield (GY) was calculated and grafted WTD's physicochemical properties were confirmed. Finally, the compatibility of irradiated ethylene vinyl acetate (EVA) with the integration of un-grafted WTD and grafted WTD were determined and compared. Electron beam (EB) irradiation dose at 100 kGy and lower is preferred in this study for WTD, as it has minimal effect on the WTD and maintains the WTD stability upon irradiation. In addition, the 0.4 wt% of Tween 20 (Tw-20) surfactant was chosen as the optimal amount needed as the amount is sufficient to maintain the stability of the TPGDA emulsion during the grafting process for 24 hours. The RIG technique was successful in this experiment, with a maximum GY of 930 % obtained at an ideal grafting parameter of 5 w/v % monomer concentration, 60 kGy absorbed radiation dosage, 3 h reaction time, and 60 ºC reaction temperature. According to the chemical identification and wettability analysis, the RIG method successfully introduced a large number of carbonyl groups into the WTD surface, as demonstrated by the creation of a new peak at 1720 cm-1 and a reduction in the angle of contact between the rubber surface and the water. The grafted WTD surface morphology has thickened, swelled, and coated in comparison to WTD. Additionally, it can be shown that by integrating the TPGDA monomer into the backbone of the WTD, the grafted WTD's average diameter was expanded by approximately 111.5 %. The incorporation of non-grafted WTD in the EVA blend decreased the tensile strength and hardness of the blend. However, the EVA blend containing grafted WTD has higher tensile strength and hardness compared to EVA blend with non-grafted WTD. An irradiated blend containing grafted WTD has shown an increase in tensile strength as well as hardness. The increment is due to the radiation-induced crosslinking process and improved compatibility between the grafted WTD and EVA matrix in the blend. It can also be seen that the gel content increase as the irradiation dose increases which further prove the increase in crosslinking density in the blend. The findings indicate that surface modification of WTD using the RIG technique is successful, resulting in an improvement in mechanical properties as a result of better interfacial bonding between the grafted WTD and the EVA blend.
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PublicationNovel hybrid mechanical cleaning process of raw edible bird nest using fruit based bio-enzymes(Universiti Malaysia Perlis (UniMAP), 2021)Edible bird’s nest (EBN) is made of salivary secretions from swiftlet called Aerodynamus Fuciphaga. It is consumed as a delicacy known as the “Caviar of the East” or as medicinal food in traditional Chinese medicine for health ranging from enhancing complexion, alleviating asthma, and strengthening the immune system. The tedious process of cleaning the feathers and dirt requires skilled and patient labor, since this process is time consuming due to the size of the feathers and dirt that is hardly seen. This study is conducted to test the effectiveness of using plant enzymes incorporated in a mechanical shaker to facilitate the cleaning process of EBN as quality improvement. Plant enzyme used are bromelain and papain reviewed to be the important plant-based enzyme normally used in various industries as meat tenderizer, pharmaceutical, detergents as well as in preparation of leather and wool. Since crude enzyme contain a lot of impurities, the purification of enzyme was done using Three Phase Partitioning (TPP) technique that uses ammonium sulfate and t-butanol as the medium of purification. The optimized operating condition for maximum specific enzyme activity on papain (1.1362 CDU/mg at ammonium sulfate concentration of 52.34%, t-butanol to enzyme ratio of 1.61:1.0 and at pH 6.88) and bromelain (1.8036CDU/mg at ammonium sulfate concentration of 47.5%, t-butanol to enzyme ratio of 1.5:1.0 and at pH 7.3) was predicted using the developed model with high accuracy (95% confidence level) and reproducibility. Optimization study for mechanical cleaning process of EBN using the mechanical shaker with the aid of enzyme was investigated. The effects of micro bubble time, shaking time and concentration of enzyme on the cleanliness of EBN was also investigated. Based on the OFAT studies, the optimum microbubble time was determined to be 5min, shaking time at 5min while enzyme concentration was at 5g/L. From the FTIR analysis conducted, it was observed that all samples with and without enzyme had similar trend in the fingerprint region (4000 cm-1 to 1000 cm-1). Thus showing that enzyme treated EBN does not alter the nutritional content in EBN. From SEM analysis, mites and feather strand was not visible in enzyme treated EBN. Comparison of manual cleaned EBN with papain and bromelain treated EBN shows an increase in protein content of 17.38% and 17.81% respectively and carbohydrate content of 8.56% and 10.39% respectively. Results showed that bird nest after treatment with enzyme has better quality and can replace traditional cleaning process of edible bird nest which is tedious and time consuming. It took only 10 minutes compared to 1 hour per sample using mechanical shaker incorporated with enzymes. Cleaned EBN can fetch a higher market value compared to raw edible bird nest.
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PublicationA study on rice husk ash-based activated carbon in different forms through adsorption isotherm(Universiti Malaysia Perlis (UniMAP), 2024)Rice husk ash (RHA) is a by-product generated by rice mills during the rice drying process, and it is abundantly produced in Malaysia every year. Without proper management can result in severe environmental issues, including water and air pollution. Therefore, in this study, chemical activation process was utilised to convert RHA into porous activated carbon (PAC) which has potential to be used in wastewater treatment. This PAC was produced by chemical activation using different types and concentration (0.5 M, 1.0 M, 1.5 M, and 2.0 M) of activating agents (sodium hydroxide (NaOH), potassium hydroxide (KOH), zinc chloride (ZnCl2) and citric acid) at a lower processing temperature of 80 ℃ for 2 hours. The porosity of the activated carbon is crucial in determining the remazol red (RR) dye adsorption properties. Results indicate that 1.0 M Na-PAC, which is RHA treated with 1.0 M NaOH, demonstrates high performance in both physical and adsorption properties. The BET surface area improved from 54.14 m2/g to 305.27 m2/g, and the pore size from 47 nm to 5 nm. The adsorption isotherm of Na-PAC is fit to Type IV, which is classified as mesoporous were also supported by the SEM image showing presence of the porous structure. Results from the XRD shows the presence of amorphous and crystalline structure which were affected by the silica structure as founded in the FTIR results. Based on this, three different forms of Na-PAC were studied: powder, macrobeads and macroballoons. The macrobeads were prepared by gelation of sodium alginate, while macroballoons used the rolling method, using EPS as a template to produce hollow sphere structure. The adsorption study using UV-spectrophotometer reveals that Na-PAC in powder form possesses a high efficiency of RR dye removal followed by macrobeads and macroballoons with 100 % dye removal at 20, 80 and 120 minutes, respectively. The adsorption equilibrium data of macroballoons and macrobeads were best fitted with the Langmuir adsorption isotherm compared to the Freundlich adsorption isotherm. It shows that the adsorption process occurs in monolayer at the surface of the Na-PAC. Powder and macrobeads forms show good removal efficiency of RR dye, however, both are difficult to manage and separate at the end of the process in the actual application. Therefore, the self-floating properties and adsorption capability of macroballoons give an advantage as the optimised sample to study the effect of different types of binder. Four types of binders were employed (epoxy resin, sodium alginate, silicone resin and grout) to produce macroballoons. Results demonstrated that sodium alginate macroballoon possesses better adsorption with more 80 % of dye removal within 120 minutes as compared to the remaining three binders. This is due to the sodium alginate used did not block the adsorption site on the surface of Na-PAC, meanwhile Na-PAC in grout dispersedly in dye solution, Na-PAC in silicone and epoxy hindered from adsorption process. In conclusion, 1.0 Na-PAC produced high porosity activated carbon that was able to remove the RR dye within the allotted time when applied in three distinct forms for the adsorption process. The types of binder also affect the adsorption ability, giving sodium alginate the most suitable binder to produce macroballoons without hindering the adsorption process.
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PublicationEffect of filler treatment on the mechanical properties of silica filled epoxy composites(Universiti Malaysia Perlis (UniMAP), 2010)In this research, filler treatment of silica was performed using (3-Aminopropyl)trimethoxysilane. Silica filled epoxy composites of 0, 2.5, 5, 7.5 and 10 vol.% were prepared. The mechanical properties of treated and untreated silica filled epoxy composites were characterized using tensile, flexural, hardness and impact testing methods. Filler treatment of silica increased the tensile, flexural and impact strength of the silica filled epoxy composites as well as their hardness. The effect of filler treatment on tensile and flexural strains could not be established due to insignificant testing data. The effect of filler treatment on the modulus of silica filled epoxy is negligible as the strength ofthe filler-matrix interphase has no significant effect on the modulus of the composites. From the DMA, fiiJer treatment showed to decrease the glass transition temperature. The estimated crosslink density of treated silica filled epoxy composites was lower than their untreated counterpart. From FTIR analysis, two new peaks emerged for the treated silica, signifying effective filler treatment.
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PublicationThe effect of silicon dioxide on the elctrical conductivity of polypyrrole/poly (vinlychloride) blends as a conducting polymer for the ionic solutions detector(Universiti Malaysia Perlis (UniMAP), 2010)Polypyrrole/poly (vinyl chloride)-silicon dioxide conducting polymer composites has been investigated as conducting polymer for ionic solutions detector. These composites were prepared by mixing polypyrrole doped with carbon black and different of silicon dioxide loading as variable. The mixture was dissolved in 1-methyl-2-pyrrolidinone and then heated under boiling point to obtain conductive polymer solution. Poly (vinylchloride) carboxylated was dissolved in Tetrahydrofuran (THF) and heated until it becomes gel. The PPy/Si02 blend was mixed with PVC gel which was used as binder to improve the adhesion of the sensing material on sensor electrodes. PPy/PVC-Si02 conductive polymer composites samples had been characterized by FTIR DSC and XRD analysis. After the dropping of the samples to surface of PCB board of sensors, they dried into oven and then connected to precision multimeter to measure their resistance when applied to the solutions. The results showed the electrical conductivity increased with increasing Si02 content in composite. The PPy/PVC blends under SEM micrographs and XRD characterizations exhibited the agglomeration and intercalation between PPy and PVC/Si02 which supported the electrical conductivity result. The Potassium chlorate exhibited highest electrical conductivity compared to other solutions. The intermolecular interaction between PPy/PVC with Si02 is evidenced from FTIR analysis.