Khor Shing Fhan
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Preferred name
Khor Shing Fhan
Official Name
Shing Fhan, Khor
Alternative Name
Khor, S. F.
Fhan, Khor Shing
Shing, Fhan Khor
Khor, Shing F.
Shing Fhan, Khor
Main Affiliation
Scopus Author ID
35242874900
Researcher ID
W-7216-2019

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  • Publication
    Morphological and optical properties of porous hydroxyapatite/cornstarch (HAp/Cs) composites
    ( 2020-01-01)
    Beh C.Y.
    ;
    Cheng Ee Meng
    ;
    Nashrul Fazli Mohd Nasir
    ;
    Mohd Tarmizi E.Z.
    ;
    Eng S.K.
    ;
    Mohd Shukry Abdul Majid
    ;
    Mohd Ridzuan Mohd Jamir
    ;
    Khor Shing Fhan
    ;
    Ahmad Saad F.S.
    This paper presents the correlation between the morphological characteristics and the diffuse reflectance (optical properties) of the porous hydroxyapatite/cornstarch (HAp/Cs) composites with various starch proportions (30, 40, 50, 60, 70, 80 and 90 wt%). The porous composites were measured via SEM and enhanced by image processing to find the average pore size, strut width, and average surface roughness. The average porosity of the porous composites was measured using liquid displacement method. The diffuse reflectance spectroscopy was implemented to investigate the diffuse reflectance and the corresponding optical band gap energy of the porous composites in the 500e900 nm range. A relationship between morphological characteristics and diffuse reflectance properties were established using Pearson's correlation coefficient. The findings of the study depict that a strong correlation can be noticed between optical band gap energy with porosity, pore sizes and surface roughness of the porous composites. Meanwhile, the strong correlations between the diffuse reflectance spectral gradient with surface roughness can be observed. The moderate correlations can be observed between the diffuse reflectance spectral gradient with pore sizes and strut width of the porous composites.
      2
  • Publication
    Complex Impedance and Modulus Analysis on Porous and Non-Porous Scaffold Composites Due to Effect of Hydroxyapatite/Starch Proportion
    ( 2023-01-01)
    Beh C.Y.
    ;
    Cheng Ee Meng
    ;
    Tan X.J.
    ;
    Mohd Nasir N.F.
    ;
    Mohd Shukry Abdul Majid
    ;
    Mohd Ridzuan Mohd Jamir
    ;
    Khor Shing Fhan
    ;
    Lee K.Y.
    ;
    Che Wan Sharifah Robiah Mohamad
    This study aims to investigate the electric responses (complex modulus and complex impedance analysis) of hydroxyapatite/starch bone scaffold as a function of hydroxyapatite/starch proportion and the microstructural features. Hence, the non-porous and porous hydroxyapatite/starch composites were fabricated with various hydroxyapatite/starch proportions (70/30, 60/40, 50/50, 40/60, 30/70, 20/80, and 10/90 wt/wt%). Microstructural analysis of the porous hydroxyapatite/starch composites was carried out by using scanning electron microscopy. It shows that the formation of hierarchical porous microstructures with high porosity is more significant at a high starch proportion. The complex modulus and complex impedance analysis were conducted to investigate the electrical conduction mechanism of the hydroxyapatite/starch composites via dielectric spectroscopy within a frequency range from 5 MHz to 12 GHz. The electrical responses of the hydroxyapatite/starch composites are highly dependent on the frequency, material proportion, and microstructures. High starch proportion and highly porous hierarchical microstructures enhance the electrical responses of the hydroxyapatite/starch composite. The material proportion and microstructure features of the hydroxyapatite/starch composites can be indirectly reflected by the simulated electrical parameters of the equivalent electrical circuit models.
      4
  • Publication
    Low frequency dielectric and optical behavior on physicochemical properties of hydroxyapatite/cornstarch composite
    ( 2021-10-15)
    Beh C.Y.
    ;
    Cheng Ee Meng
    ;
    Nashrul Fazli Mohd Nasir
    ;
    Khor Shing Fhan
    ;
    Eng S.K.
    ;
    Mohd Shukry Abdul Majid
    ;
    Mohd Ridzuan Mohd Jamir
    ;
    Lee K.Y.
    An investigation on relationship among the physicochemical, optical and dielectric properties of the hydroxyapatite/cornstarch (HA/Cs) composites with the starch proportion of 30, 40, 50, 60, 70, 80 and 90 wt% is presented in this work. The HA/Cs composites have been characterized via FTIR, XRD, DRS and impedance analyzer. This work depicts that the strong interaction is exhibited between the hydroxyapatite nanoparticles and starch as the starch proportion increases. This increment trend results in the higher crystallinity of the HA/Cs composites. The highly crystallized HA/Cs with hydroxyapatite nucleation center presents low optical properties (diffuse reflectance and optical band gap energy). The HA/Cs composite with 80 wt% starch proportion (H2C8) show higher dielectric properties (dielectric constant, loss factor and conductivity) due to the stronger interfacial interaction and close-packed HA/Cs crystalline structure. The relationship among the physicochemical, optical and dielectric properties of the HA/Cs composite is studied in this work for potential of instrumentation design.
      2  1
  • Publication
    Regression Analysis of the Dielectric and Morphological Properties for Porous Nanohydroxyapatite/Starch Composites: A Correlative Study
    ( 2022-05-01)
    Beh C.Y.
    ;
    Cheng Ee Meng
    ;
    Nashrul Fazli Mohd Nasir
    ;
    Mohd Tarmizi E.Z.
    ;
    Mohd Shukry Abdul Majid
    ;
    Mohd Ridzuan Mohd Jamir
    ;
    Lee K.Y.
    ;
    Khor Shing Fhan
    This paper aims to investigate the dielectric properties, i.e., dielectric constant (ε′), dielectric loss factor (ε″), dielectric tangent loss (tan δ), electrical conductivity (σ), and penetration depth (Dp), of the porous nanohydroxyapatite/starch composites in the function of starch proportion, pore size, and porosity over a broad band frequency range of 5 MHz–12 GHz. The porous nanohydroxyapatite/starch composites were fabricated using different starch proportions ranging from 30 to 90 wt%. The results reveal that the dielectric properties and the microstructural features of the porous nanohydroxyapatite/starch composites can be enhanced by the increment in the starch proportion. Nevertheless, the composite with 80 wt% of starch proportion exhibit low dielectric properties (ε′, ε″, tan δ, and σ) and a high penetration depth because of its highly interconnected porous microstructures. The dielectric properties of the porous nanohydroxyapatite/starch composites are highly dependent on starch proportion, average pore size, and porosity. The regression models are developed to express the dielectric properties of the porous nanohydroxyapatite/starch composites (R2 > 0.96) in the function of starch proportion, pore size, and porosity from 1 to 11 GHz. This dielectric study can facilitate the assessment of bone scaffold design in bone tissue engineering applications.
      1  18
  • Publication
    Dielectric Properties of Hydrothermally Modified Potato, Corn, and Rice Starch
    ( 2022-06-01)
    Beh C.Y.
    ;
    Cheng Ee Meng
    ;
    Nashrul Fazli Mohd Nasir
    ;
    Mohd Tarmizi E.Z.
    ;
    Khor Shing Fhan
    ;
    Mohd Shukry Abdul Majid
    ;
    Lee K.Y.
    ;
    Mohd Ridzuan Mohd Jamir
    The effect of starch granule sizes, shapes, composition, and frequency on the dielectric properties (dielectric constant, loss factor, and conductivity) of native and hydrothermally modified starches (potato, corn, and rice starch) are investigated in this work. Dielectric properties are determined from 5 Hz to 5 GHz. The modified starches exhibit lower dielectric properties than the native starches from 5 Hz to 5 GHz due to the disruption of the native polysaccharide’s molecular arrangement. The modified potato starch shows the highest loss factor (208.12 at 50 Hz and 19.95 at 500 Hz) and stable conductivity (~5.33 × 10−7 S/m at 50 Hz and 500 Hz) due to the larger continuous network structure after hydrothermal modification. The rice starch shows the largest difference in dielectric constant (47.30%) and loss factor (71.42%) between the modified form and native form in the frequency range of 5 MHz–5 GHz. This is due to the restriction of dipole motions in the closely packed structure after hydrothermal modification. The findings indicate that the quality of starch modification can be characterized by dielectric properties for assisting starch-based plastic production’s design.
      2
  • Publication
    Dielectric, Electrical Conductivity, and Thermal Stability Studies of Cellulosic Fibers Reinforced Polylactic Acid Composites
    ( 2022-01-01)
    Azahari A.N.
    ;
    Mohd Ridzuan Mohd Jamir
    ;
    Mohd Shukry Abdul Majid
    ;
    Maslinda Abu Bakar @ Yahaya
    ;
    Cheng Ee Meng
    ;
    Khor Shing Fhan
    ;
    Rahman M.T.A.
    ;
    Sulaiman M.H.
    In this study, biodegradable polylactic acid (PLA) composites were reinforced with three different natural fibers, were bamboo (BF), sugarcane (SF), and banana pseudostem (BPF) fibers, and prepared at different loadings (10, 20, and 30 wt.%). The solvent casting particulate leaching method was implemented to produce porous composites, and salt was used as the particulate material. The dielectric properties of the PLA/BF, PLA/SF, and PLA/BF composites were studied for different loadings of cellulosic fibers. The composites were observed using scanning electron microscopy (SEM), and the PLA composites with 30 wt.% filler content were analyzed using Fourier transform infrared (FTIR) and thermogravimetric analysis (TGA). According to the dielectric tests, all PLA/BF, PLA/SF, and PLA/BPF composites have low dielectric constants and dielectric loss. The PLA/BF composites exhibited the highest dielectric constant, dielectric loss, and electrical conductivity, followed by the PLA/BF and PLA/SF composites. The morphology of the composites showed their porous structure. The FTIR spectra showed the main constituents presented in the composites, and the PLA/BF showed higher thermal stability than the other composites.
      2  29
  • Publication
    Lumped-element circuit modeling for composite scaffold with nano-hydroxyapatite and wangi rice starch
    ( 2023)
    Xiao Jian Tan
    ;
    Cheng Ee Meng
    ;
    Nashrul Fazli Mohd Nasir
    ;
    Mohd Shukry Abdul Majid
    ;
    Mohd Ridzuan Mohd Jamir
    ;
    Khor Shing Fhan
    ;
    Kim Yee Lee
    ;
    Kok Yeow You
    ;
    Che Wan Sharifah Robiah Mohamad
    Mechanistic studies of the interaction of electromagnetic (EM) fields with biomaterials has motivated a growing need for accurate models to describe the EM behavior of biomaterials exposed to these fields. In this paper, biodegradable bone scaffolds were fabricated using Wangi rice starch and nano-hydroxyapatite (nHA). The effects of porosity and composition on the fabricated scaffold were discussed via electrical impedance spectroscopy analysis. The fabricated scaffold was subjected to an electromagnetic field within the X-band and Ku-band (microwave spectrum) during impedance/dielectric measurement. The impedance spectra were analyzed with lumped-element models. The impedance spectra of the scaffold can be embodied in equivalent circuit models composed of passive components of the circuit, i.e., resistors, inductors and capacitors. It represents the morphological, structural and chemical characteristics of the bone scaffold. The developed models describe the impedance characteristics of plant tissue. In this study, it was found that the ε′ and ε″ of scaffold composites exhibited up and down trends over frequencies for both X-band and Ku-band. The circuit models presented the lowest mean percentage errors of Z′ and Z″, i.e., 3.60% and 13.80%, respectively.
      21  1
  • Publication
    Regression analysis of the dielectric and morphological properties for porous Nanohydroxyapatite/Starch composites: a correlative study
    ( 2022)
    Chong You Beh
    ;
    Cheng Ee Meng
    ;
    Nashrul Fazli Mohd Nasir
    ;
    Mohd Shukry Abdul Majid
    ;
    Khor Shing Fhan
    ;
    Mohd Ridzuan Mohd Jamir
    ;
    Emma Ziezie Mohd Tarmizi
    ;
    Kim Yee Lee
    This paper aims to investigate the dielectric properties, i.e., dielectric constant (ε′), dielectric loss factor (ε″), dielectric tangent loss (tan δ), electrical conductivity (σ), and penetration depth (Dp), of the porous nanohydroxyapatite/starch composites in the function of starch proportion, pore size, and porosity over a broad band frequency range of 5 MHz–12 GHz. The porous nanohydroxyapatite/starch composites were fabricated using different starch proportions ranging from 30 to 90 wt%. The results reveal that the dielectric properties and the microstructural features of the porous nanohydroxyapatite/starch composites can be enhanced by the increment in the starch proportion. Nevertheless, the composite with 80 wt% of starch proportion exhibit low dielectric properties (ε′, ε″, tan δ, and σ) and a high penetration depth because of its highly interconnected porous microstructures. The dielectric properties of the porous nanohydroxyapatite/starch composites are highly dependent on starch proportion, average pore size, and porosity. The regression models are developed to express the dielectric properties of the porous nanohydroxyapatite/starch composites (R2 > 0.96) in the function of starch proportion, pore size, and porosity from 1 to 11 GHz. This dielectric study can facilitate the assessment of bone scaffold design in bone tissue engineering applications.
      1  18
  • Publication
    Microwave dielectric analysis on adhesive disbond in acrylic glass (Poly (Methyl Methacrylate)) at KU-band
    ( 2020-10-01)
    Cheng Ee Meng
    ;
    Mohd Afendi Rojan
    ;
    Shahriman Abu Bakar
    ;
    Zuradzman Mohamad Razlan
    ;
    You K.Y.
    ;
    Nashrul Fazli Mohd Nasir
    ;
    Mohd Shukry Abdul Majid
    ;
    Khairul Salleh Basaruddin
    ;
    Mohd Ridzuan Mohd Jamir
    ;
    Beh C.Y.
    ;
    Khor Shing Fhan
    A microwave dielectric spectroscopy for detecting adhesive disbonds between acrylic glass (aka Poly (methyl methacrylate)) was discussed. The adhesive bond was developed using epoxy resin and acrylate. The level of joint disbond can be quantified using Young Modulus. In this work, the strength of bond is affected by radius of air void within adhesive bond. A high-frequency electromagnetic wave propagated through two joint acrylic glass with acrylate and epoxy adhesive using waveguide adaptor WR90 in conjunction with professional network analyser. This electromagnetic wave is reflected and transmitted at the bond interface due to mismatch impedance at adhesive bond. The output is a dielectric properties that characterizes the bond interface. The increment of Young Modulus leads to increment of dielectric constant and loss factor for epoxy resin and acrylates, respectively.
      7  37
  • Publication
    Lumped-Element Circuit Modeling for Composite Scaffold with Nano-Hydroxyapatite and Wangi Rice Starch
    ( 2023-01-01)
    Tan X.J.
    ;
    Cheng Ee Meng
    ;
    Mohd Shukry Abdul Majid
    ;
    Nashrul Fazli Mohd Nasir
    ;
    Lee K.Y.
    ;
    You K.Y.
    ;
    Mohd Ridzuan Mohd Jamir
    ;
    Che Wan Sharifah Robiah Mohamad
    ;
    Khor Shing Fhan
    Mechanistic studies of the interaction of electromagnetic (EM) fields with biomaterials has motivated a growing need for accurate models to describe the EM behavior of biomaterials exposed to these fields. In this paper, biodegradable bone scaffolds were fabricated using Wangi rice starch and nano-hydroxyapatite (nHA). The effects of porosity and composition on the fabricated scaffold were discussed via electrical impedance spectroscopy analysis. The fabricated scaffold was subjected to an electromagnetic field within the X-band and Ku-band (microwave spectrum) during impedance/dielectric measurement. The impedance spectra were analyzed with lumped-element models. The impedance spectra of the scaffold can be embodied in equivalent circuit models composed of passive components of the circuit, i.e., resistors, inductors and capacitors. It represents the morphological, structural and chemical characteristics of the bone scaffold. The developed models describe the impedance characteristics of plant tissue. In this study, it was found that the ε′ and ε″ of scaffold composites exhibited up and down trends over frequencies for both X-band and Ku-band. The circuit models presented the lowest mean percentage errors of Z′ and Z″, i.e., 3.60% and 13.80%, respectively.
      2  31