Research Output
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PublicationEffect of Microwave Power and Clamping Pressure on the Microwave Welding of Polypropylene Using Silicon Carbide Nanowhiskers as Microwave Susceptor( 2022-01-01)Due to their excellent dielectric properties and the rapid response to microwave irradiation, silicon carbide nanowhiskers (SiCNWs) were employed as microwave susceptor in this study to absorb microwave and locally melt the surrounding polypropylene (PP) substrates for the joining of PP substrates. Complete welded joint is formed after the melted PP was cooled and resolidified. Other than microwave susceptor, SiCNWs also acted as the nanofillers in strengthening the welded joint through the formation of SiCNWs reinforced PP nanocomposite at the interface of PP substrates. Besides, the effect of microwave power on the microwave welding of PP substrates using SiCNWs as susceptor was studied and reported. It was found that the tensile strength and modulus of elasticity of the welded joint improved as microwave power increased. However, it deteriorates the flexibility of the welded joint as high stiffness SiCNWs were incorporated deeper into the PP matrix which restricted the PP chain mobility. Aside from microwave power, clamping pressure is also critical in determining the mechanical properties of a welded joint. When compared to unclamped welded joint, the tensile strength, modulus of elasticity and flexibility of welded joint subjected to clamping pressure improved drastically. Moreover, the tensile strength of welded joint increased when the clamping pressure was increased from P1 to P3, but decreased when the clamping pressure was further increased to P4 due to the occurrence of flashing at welded joint. The formation mechanism of SiCNWs reinforced PP welded joint was also proposed in this study. Compared to conventional welding, this welding process is easy, straightforward and is able to produce welded joint with outstanding mechanical properties via precise controlling of the processing parameters. Thus, microwave welding is thought to offer an option for the joining of thermoplastics and other applications.
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PublicationAlkalinized extraction of silica-aluminium nanocomposite from traditional Chinese joss paper: Optical characterizations( 2020-03-01)The Chinese traditional joss paper has been recycled and silica and aluminium nanocomposite production is reported in the current research, using an alkalinization procedure. Characterization of silica and aluminium nanocomposite extracted was performed using field-emission transmission electron microscope (FETEM), field-emission scanning electron microscope (FESEM), UV–visible spectroscopy, high-power optical microscopy (HPM) and 3D nano profiler, indicates the size, shape and particle distribution, eventually reveals the purity of silica and aluminium nanocomposite synthesized. The silica-aluminium nanocrystal synthesized from joss paper waste was found to be ~15 nm size range under FETEM analysis and FESEM analysis revealed the uniform spherical shape. The energy disperse spectroscopy (EDX) data attained from FESEM analysis affirmed the synthesis of silica-aluminium nanocomposite with greater purity since the ratio of silicon to aluminium observed in EDX spectra was 13.24 to 7.96. HPM indicated the size of agglomerated aluminosilicate is 36.74 μm whereas 3D nano profiler has proven that the height of nanocrystal synthesized from joss paper waste is 234.37 μm. Band gap value of 3.84 eV, calculated using UV–vis absorbance readings further affirmed the size of nanocomposite which is in good agreement with presented results.
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PublicationSurface charge transduction enhancement on nano-silica and - Alumina integrated planar electrode for hybrid DNA determination( 2021-06-01)This study represents the surface charge transduction, an efficient and inexpensive biosensor with modifications by silica-alumina entities and determination of gene sequence hybridization. The sensing surface was made by the planar aluminium interdigitated electrode on silicon substrate. Silica and alumina nanoparticles were engineered on the planar transducer surface and the device sensitivity was investigated. The morphology of silica and alumina particles was characterized through the high-resolution election microscopic analyses and revealed the spherical shaped nanoscale sizes at the range of 45–100 nm. The elemental compositions of silica and alumina nanomaterial were affirmed through energy disperse spectroscopy as prominent peaks of Si, Al and O were observed. Selected area electron diffraction analysis of silica and alumina justified their crystalline and amorphous nature, respectively. XRD analysis revealed the expending cristobalite state of silica crystal and γ-alumina for planar electrode surface enhancement. Fourier transform infrared spectroscopy peak observed at 1094 cm−1 revealed the asymmetric stretching of silica nanoparticles whereas the projecting peak observed at 806 cm−1. Additionally, Al–O stretch and Al–O–Al bending modes were justified with the peaks at 585 and 825 cm−1, respectively. Band gap values of silica and alumina computed were 6.75 eV and 3.20 eV, respectively. The results of DNA probe immobilization and complementation have affirmed that silica modified transducer shows the lowest detection at 10 aM whereas alumina modified transducer displayed insignificant current signal and failed to detect DNA hybridization. To investigate the effect of silica entity and its nanocomposite in detecting DNA hybridization, aluminosilicate nanocomposite was deposited on transducer and attained highly sensitive gene detection. Based on the coefficient regression value, aluminosilicate nanocomposite modified planar transducer has shown good device sensitivity (R2 = 0.96) in contrast to silica and alumina entities.
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PublicationNanostructured aluminosilicate from fly ash: Potential approach in waste utilization for industrial and medical applications( 2020-04-20)Fly ash is found as a significant solid waste released from power plants to the atmosphere, but its qualitative and quantitative consumptions for the sustainability are ambiguous. The main issues aroused with the disposal of fly ash are the requirement of a large land area for landfills, cause toxicity and pollution to the soil and groundwater due to the accumulation of heavy metals. Although fly ash is highly recommended for soil amelioration and cement manufacturing, the ultimate usage of the solid waste causes unsatisfactory effect to the ground system and cementitious product, respectively. Apart from direct utilization and disposal of fly ash, it has been well reported in literature for the synthesis of nanosized particles due to its enrichment in silica, kaolin, iron, and alumina. With this regard, aluminosilicates have been acknowledged as one of the prospective nanocomposites synthesized from fly ash. It has proven that naturally occurring geopolymerization of fly ash under alkaline medium results is in the formation of aluminosilicates. As such, synthetic aluminosilicates were highly encouraged to extract from fly ash in large scale due to their excellent physiochemical properties and applications. This overview intends to fill-up the knowledge gap through critically reviewing about fly ash waste for the synthesis of aluminosilicate nanocomposite. The applications of fly ash derived aluminosilicates in industries such as wastewater treatment, agriculture system and as antioxidants are gleaned. Besides the heavy industrial potential, this review encompasses the prospective alternative consumption of fly ash for the production of nanostructured aluminosilicates and their comprehensive assessment in medical applications, especially in drug carrier and drug delivery systems, bone engineering, biosensors, hemodialysis, and intestinal therapeutics.
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PublicationMultidimensional (0D-3D) nanostructures for lung cancer biomarker analysis: Comprehensive assessment on current diagnostics( 2019-09-15)The pragmatic outcome of a lung cancer diagnosis is closely interrelated in reducing the number of fatal death caused by the world's top cancerous disease. Regardless of the advancement made in understanding lung tumor, and its multimodal treatment, in general the percentage of survival remain low. Late diagnosis of a cancerous cell in patients is the major hurdle for the above circumstances. In the new era of a lung cancer diagnosis with low cost, portable and non-invasive clinical sampling, nanotechnology is at its inflection point where current researches focus on the implementation of biosensor conjugated nanomaterials for the generation of the ideal sensing. The present review encloses the superiority of nanomaterials from zero to three-dimensional nanostructures in its discrete and nanocomposites nanotopography on sensing lung cancer biomarkers. Recent researches conducted on definitive nanomaterials and nanocomposites at multiple dimension with distinctive physiochemical property were focused to subside the cases associated with lung cancer through the development of novel biosensors. The hurdles encountered in the recent research and future preference with prognostic clinical lung cancer diagnosis using multidimensional nanomaterials and its composites are presented.
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PublicationFeasibility study on microwave welding of thermoplastic using multiwalled carbon nanotubes as susceptor( 2021-01-01)Despite manufacturers’ goal of molding single component products from plastics, the structures of some of the products are far too complex to be molded as a single piece. Therefore, assembly of subcomponents into the final products is important for the manufacturing of many plastic-based products. To date, welding is the most efficient joining method for plastics. In this study, multiwalled carbon nanotubes were proposed as the susceptor for the microwave welding of high-density polyethylene considering multiwalled carbon nanotube is a good microwave absorber. multiwalled carbon nanotubes were first dispersed in ethanol in an ultrasonic bath to obtain a homogeneous dispersion. Multiwalled carbon nanotubes dispersion was dropped on the targeted area of the prepared dumbbell-shaped sample and dried in an oven at 45°C for 30 min. The sample was then subjected to 800 W microwave irradiation in the domestic microwave oven. The strength of the weld was tested by using tensile testing. Besides, the cross section of the welded joint was characterized by using scanning electron microscopy. The effect of microwave heating duration and the multiwalled carbon nanotube concentration in the dispersion were studied. It was found that the joint strength increased as the heating duration increase from 2 s to 8 s but decreased when the heating duration was further extended to 10 s. Scanning electron microscopic images showed that voids were formed at the joint interface when 10 s was used and resulted in the lowering of joint strength. In the study of the effect of the multiwalled carbon nanotube concentration in the dispersion, joint strength increased when the multiwalled carbon nanotubes concentration increased from 0.25 wt% to 0.75 wt%. However, the joint strength of sample with 1.00 wt% multiwalled carbon nanotube concentration decreased. The presence of a thick unwelded multiwalled carbon nanotubes layer at the joint interface for sample with 1.00 wt% multiwalled carbon nanotubes concentration as shown in scanning electron microscopic image was believed to cause the lowering of joint strength.
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