Voon Chun Hong
Thumbnail Image
Preferred name
Voon Chun Hong
Official Name
Hong, Voon Chun
Alternative Name
Voon, C. H.
Voon, Chun Hong
Hong, Voon Chun
Hong, V. C.
Main Affiliation
Scopus Author ID
55334719400
Researcher ID
D-2050-2015

Research Output

Filters

49
Reset filters

Settings
Now showing 1 - 10 of 49
Thumbnail Image
Publication

Sustainable production of graphene oxide with ascorbic acid reduction characterization and insights

2024-10 , Thaddeus Lee , Chun Hui Tan , Chai Yan Ng , Foo Wah Low , Hing Wah Lee , Voon Chun Hong

In this study, graphene oxide (GO) was synthesized from graphite powder using KMnO4 and a concentrated mixture of H2SO4/H3PO4. The obtained GO was subsequently reduced using ascorbic acid. The ratios of H2SO4 to H3PO4 and KMnO4 to graphite powder were kept constant. The synthesized GO and reduced graphene oxide (rGO) were evaluated using UV-visible spectroscopy, FT-IR spectroscopy, XRD, SEM, and EDX. The findings showed that processing graphite powder with KMnO4 at 60 °C for 12 hours resulted in a high degree of oxidation and minimal defects. Furthermore, ascorbic acid, an alternative to highly toxic hydrazine, aided in eliminating oxygen-containing functional groups in the rGO. This study focuses on the properties of GO produced using the improved Hummer's method, and the changes observed after chemical reduction.

View
Thumbnail Image
Publication

Oil palm lignin-derived laser scribed graphene in neutral electrolyte for high-performance microsupercapacitor application

2023-10-01 , Remesh S. , Vasudevan M. , Perumal V. , Ovinis M. , Karuppanan S. , Edison T.N.J.I. , Raja P.B. , Ibrahim M.N.M. , Voon Chun Hong , Arumugam N. , Kumar R.S.

Lignin is a renewable natural resource that could be derived from oil palm empty fruit bunches. It has generated significant interest as a precursor in synthesizing graphene as anode and cathode material for supercapacitors. In this paper, we report the synthesis of 3D hierarchical Laser Scribed Graphene (LSG) on a flexible polyimide substrate from lignin extracted from empty fruit bunches (EFB) of oil palm for microsupercapacitor applications. The intensity and speed of the laser have been tuned to yield densely compacted oil palm lignin LSG at a laser power of 70% and a speed of 30% (OPL-LSG 7030). OPL-LSG 7030 possessed lower equivalent series resistance of 60.1 Ω and a larger crystalline size of ∼31 nm than the rest of the tested samples. It exhibited exceptional areal capacitance of 30.77 mFcm−2 at a current density of 0.08 mAcm−2, an energy density of 0.00176 mWhcm−2 and a power density of 0.25 mWcm−2 when using a unique neutral PAAS/K2SO4 gel electrolyte. It achieved excellent capacitance retention of 88.4% after 5000 charge/discharge cycles and remarkable mechanical stability of 95% after 400 bending cycles. Furthermore, electrochemical studies revealed the redox properties of readily available quinone/ hydroquinone in the oil palm lignin, which could be inherited in graphene electrodes through a feasible and affordable approach for flexible green energy storage applications.

View
Thumbnail Image
Publication

Facile Electrical DNA Genosensor for Human Papillomavirus (HPV 58) for Early Detection of Cervical Cancer

2023-07-01 , Jaapar F.N. , Nor Azizah Parmin , Halim N.H.A. , Uda Hashim , Subash Chandra Bose Gopinath , Ruslinda A. Rahim , Nadzirah S. , Voon Chun Hong , Muhammad Nur Aiman Uda , Ang W.C. , Zakaria I.I. , Rejali Z. , Afzan A. , Hamzah A.A. , Dee C.F. , Halim F.S.

For decades, a Pap smear test has been applied as a conventional method in detecting Human Papillomavirus caused cervical cancer. False-positive results were also recorded while using it as conventional method. Current biosensor such as Hybrid (II) Capture resulted in higher time consumption and cost. s Meanwhile, in this study we provided facile, mini, rapid, highly sensitive, eco-friendly, and cost-effective sensing system focusing on HPV strain 58 (HPV58) in a nano-size lab-on-chip technology genosensor. 30-mer of virus ssDNA designed and analyzed as a probe via bioinformatics tools such as GenBank, Basic Local Alignment Searching Tools (BLAST) and ClustalW. Nanotechnology-developed colloidal Gold-nanoparticles (AuNPs) are used in the biosensor fabrication to produce high stability and electron efficient transmission during electrical measurement. AuNPs-APTES modified on active sites of IDEs, followed by immobilization of specific probe ssDNA for HPV 58. Hydrogen binding during hybridization with its target produce electrical signals measured by KEITHLEY 2450 (Source Meter). The genosensor validated with different types of targets such as complimentary, non-complementary and single mismatch oligonucleotides. The serial dilution of target concentration has been experimented triplicate (n=3) range from 1fM to 10µM. The slope of calibration curve resulted 2.389E-0 AM-1 with regression coefficient (R2) = 0.97535.

View
Thumbnail Image
Publication

Electrochemical DNA Biosensor based on 30 nM Gold Nanoparticle Modified Electrode by Electro Less Deposition for Human Papillomavirus (HPV) 18 E6 Region

2020-07-09 , Koo Siew Kim N.S. , Parmin N.A. , Uda Hashim , Subash Chandra Bose Gopinath , Rejali Z. , Afzan A. , Muhammad Nur Aiman Uda , Muhammad Nur Afnan Uda , Voon Chun Hong

The aim of this work was to develop a novel, simple, inexpensive, sensitive an electrochemical DNA biosensor based on interdigitated electrodes (IDEs) integrated gold nanoparticle modified electrode by electro less deposition for HPV 18. The biosensor was designed with a 30 mer E6 region of HPV 18 DNA modified probe. The E6 region has been used for their clinical importance properties and suitable as recognition biomarker region. Three different target types were tested which complementary target, non-complementary target and mismatch target. All target were analyzed for detection of HPV 18 in early stages by using Dielectric Analyzer (DA), Alpha-A High-performance Frequency Analyzer, Novocontrol Technologies, Handsagen, Germany associated with the software package Windeta. Complementary target gives a positive result in HPV detection, while non-complementary and mismatch target give negative results. IDE device with 5 nm gap sizes has demonstrated a high performance towards the detection of HPV18 ssDNA target by modified with 30 nm gold nanoparticle. The electrochemical biosensor showed better performance compared to agarose gel electrophoresis assay. This technology can be used as a new and attractive sensor development for detection of virus infection in human bodies.

View
Thumbnail Image
Publication

Voltammetric DNA Biosensor for Human Papillomavirus (HPV) Strain 18 Detection

2020-07-09 , Mhd Akhir M.A. , Nor Azizah Parmin , Uda Hashim , Subash Chandra Bose Gopinath , Rejali Z. , Afzan A. , Muhammad Nur Aiman Uda , Muhammad Nur Afnan Uda , Voon Chun Hong

This research was developed to focus on the study of the voltammetric DNA biosensor for the detection of HPV strain 18. In this research, electrical DNA biosensor was expected to detect HPV strain 18 more efficiently by using electrical characterization. In this project, device inspection was conducted to make sure the functional of the gold interdigitated electrode (IDE) by using Scanning Electron Microscope (SEM). 3-Aminopropyl Triethoxysilane (APTES) solution was used for the process of surface modification to form the amine group on the surface of the device to facilitate the attachment of the DNA probe. In this project, synthetic DNA sample and DNA from the saliva of several Biosystems Engineering students were used as the target DNA. The current-voltage (I-V) electrical characterization was conducted to detect the presence of HPV strain 18 in both DNA samples. As the results, perfect alignment between the electrodes on the IDE was detected under SEM. Surface modification of the biosensor successfully conducted which is the covalent bond between APTES and DNA probe increase the electrical. Synthetic DNA shows the presence of HPV strain 18 while there was no HPV strain 18 detected in the DNA from saliva samples.

View
Thumbnail Image
Publication

Effect of zinc oxide suspension on the overall filler content of the PLA/ZnO composites and cPLA/ZnO composites

2023-01-01 , Tan M.A. , Yeoh Cheow Keat , Teh P.L. , Nor Azura Abdul Rahim , Song C.C. , Voon Chun Hong

This work aimed to study the effect of zinc oxide (ZnO) filler suspension on the mechanical, electrical, and thermal properties of polylactic acid (PLA)/ZnO and cPLA/ZnO. Fused deposition modelling, one of the additive manufacturing methods, was used to fabricate the PLA specimen. PLA was used as the main material in this project, and the ZnO suspension was added during the printing process. The speed of the dispenser (low speed = 1,000 rpm, medium speed = 1,400 rpm, and high speed = 1,800 rpm) was the parameter that was varied to control the filler content of the composite. All the samples underwent a tensile test to determine the mechanical properties, followed by the scanning electron microscopy (SEM) test to analyse the fracture surface properties of the tensile test. SEM observations showed the PLA samples' inherent smooth appearance, but the PLA/ZnO composite showed a rougher surface. PLA and cPLA composites showed an enhanced storage modulus but lower loss modulus than the pure samples. Because of the high thermal and electrical conductivity of carbon black and ZnO, cPLA composites had higher electrical and thermal conductivity than PLA composites.

View
No Thumbnail Available
Publication

Mechanical properties of rCB-pigment masterbatch in rLDPE: the effect of processing aids and water absorption test

2023 , Muhamad Al-Haqqem Abdul Hadi , Nor Azura Abdul Rahim , Chew Kang Wei , Teh Pei Leng , Voon Chun Hong , Wong Wee Chun

Homogenization of pigment is the key to coloring a plastic product evenly. In this article, the tensile properties of recovered carbon black merge with low molecular weight lubricants and other compounding ingredients in the form of pigment masterbatch (PM) added in a recycled low-density polyethylene (rLDPE) resin were evaluated. The prepared masterbatch with the varying amount and types of processing aids (A and B) was first compounded using the heated two-roll mill. Subsequently, the manually mixed masterbatch in rLDPE was put through an injection molding machine for the shaping process to produce an rLDPE pigment masterbatch composite (PMC). The tensile test was performed on the samples to evaluate the mechanical properties of the PMC. Meanwhile, the melt flow index test was executed to justify the composite flow characteristics. Fourier-transform infrared spectroscopy analysis and scanning electron microscopy were also carried out to analyze the PM and PMC chemical properties and their constructed surface morphology. Besides, X-ray diffraction analysis was performed to determine the changes in degree of crystallinity before and after the water absorption test. The addition of PM in rLDPE has slightly increased the rLDPE matrix tensile properties. While, the usage of more processing aid B in the PMC has turned out to secure better tensile properties compared to the addition of higher amount of processing aid A in the PMC. Interestingly, the tensile properties of all composites after the water absorption test were enhanced, suggesting that a stronger bond was formed during the immersion period.

View
Thumbnail Image
Publication

Effect of solvent on mechanical and physical properties of PMMA/Sic composite films

2024-12 , Auni Fakhira Che Baharudin , Lim Bee Ying , Voon Chun Hong , Teh Pei Leng , Tan Soo Jin

The selection of solvent in solution casting is crucial as it may affect the morphology and properties of the resulting composite films. In this study, the effect of solvent on the properties of poly(methyl methacrylate)/silicon carbide (PMMA/SiC) composite films was investigated. By using acetone, the solution casting was carried out at various solvent-to-solid (S/S) ratio, from 4:1 to 10:1 at room temperature. It was found that the increasing S/S ratio enhanced the tensile strength and modulus of elasticity of pristine PMMA films but deteriorated its elongation at break, up to 8:1 ratio. The crystallinity of the PMMA films was found to increase with S/S ratio, as confirmed by the higher peak intensity in X-Ray Diffraction (XRD) patterns and the SEM micrographs. In the second part of the study, by using S/S ratio of 8:1, the nano sized SiC (0.25 wt%) was added as a filler into PMMA and toluene with different ratio was added as a secondary solvent. The addition of SiC has increased the tensile strength and modulus of elasticity of PMMA/SiC but decreased its elongation at break. However, the presence of toluene reduced the tensile strength of the PMMA/SiC composite films and resulting in rougher tensile fracture surfaces as shown in SEM micrographs. The toluene with nonpolar nature had affected the distribution of SiC in PMMA. It can be concluded that the properties of the PMMA composites films can be tailored according to the needs of applications.

View
Thumbnail Image
Publication

Facile electrical DNA genosensor for human papillomavirus (HPV 58) for early detection of cervical cancer

2023-07 , F. Nadhirah Jaapar , Nor Azizah Parmin , Nur Hamidah Abdul Halim , Uda Hashim , Subash Chandra Bose Gopinath , Ruslinda A. Rahim , Sh. Nadzirah , Voon Chun Hong , Muhammad Nur Aiman Uda , Wei Chern Ang , Iffah Izzati Zakaria , Zulida Rejali , Amilia Afzan , Azrul Azlan Hamzah , Chang Fu Dee , F. Syakirah Halim

For decades, a Pap smear test has been applied as a conventional method in detecting Human Papillomavirus caused cervical cancer. False-positive results were also recorded while using it as conventional method. Current biosensor such as Hybrid (II) Capture resulted in higher time consumption and cost. s Meanwhile, in this study we provided facile, mini, rapid, highly sensitive, eco-friendly, and cost-effective sensing system focusing on HPV strain 58 (HPV58) in a nano-size lab-on-chip technology genosensor. 30-mer of virus ssDNA designed and analyzed as a probe via bioinformatics tools such as GenBank, Basic Local Alignment Searching Tools (BLAST) and ClustalW. Nanotechnology-developed colloidal Gold-nanoparticles (AuNPs) are used in the biosensor fabrication to produce high stability and electron efficient transmission during electrical measurement. AuNPs-APTES modified on active sites of IDEs, followed by immobilization of specific probe ssDNA for HPV 58. Hydrogen binding during hybridization with its target produce electrical signals measured by KEITHLEY 2450 (Source Meter). The genosensor validated with different types of targets such as complimentary, non-complementary and single mismatch oligonucleotides. The serial dilution of target concentration has been experimented triplicate (n=3) range from 1fM to 10μM. The slope of calibration curve resulted 2.389E-0 AM-1 with regression coefficient (R2) = 0.97535.

View
No Thumbnail Available
Publication

Microwave welding with SiCNW/PMMA nanocomposite thin films: enhanced joint strength and performance

2025-01 , Phey Yee Foong , Voon Chun Hong , Lim Bee Ying , Foo Wah Low , Teh Pei Leng , Nor Azizah Parmin , Subash Chandra Bose Gopinath , Veeradasan Perumal , Yeoh Cheow Keat , Nor Azura Abdul Rahim

Most previously reported susceptors for microwave welding are in powder form. In this study, a thin-film susceptor was employed due to its uniform heating rate and ease of handling. Silicon carbide nanowhisker (SiCNW) were incorporated into a poly(methyl methacrylate) (PMMA) matrix to create a nanocomposite thin film, which served as the susceptor. The microwave welding process involved three straightforward steps: fabrication of the PMMA/SiCNW nanocomposite thin film, application of the nanocomposite film to the target area, and subsequent microwave heating. Upon cooling, a robust microwave-welded joint was formed. The mechanical properties and microstructure of the welded joints were characterized using single-lap shear tests, three-point bending tests, and scanning electron microscopy. Results demonstrated that the shear strength and elastic modulus of the welded joints were optimized with increased heating time and SiCNW filler loading. This optimization is attributed to the formation of a SiCNW-filled polypropylene (PP) nanocomposite layer of increasing thickness at the welded joint interface. However, the incorporation of SiCNW also constrained the mobility of the PP chains, reducing the joint’s flexibility. Furthermore, the welded joint formed with the PMMA/SiCNW nanocomposite thin-film susceptor exhibited an 18.82% improvement in shear strength compared to joints formed with a powdered SiCNW susceptor. This study not only demonstrates the potential of PMMA/SiCNW nanocomposite thin films as efficient susceptors for microwave welding but also paves the way for developing high-performance polymer-based composite joints with improved mechanical properties for applications in the automotive, aerospace, and construction industries.

View