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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The effect of treated flue gas desulfurization (FGD) sludge addition on the properties of non-stoichiometric cordierite

2025-01 , Fatin Fatini Othman , Banjuraizah Johar , Khor Shing Fhan , Suffi Irni Alias , Nik Akmar Rejab

This study examines the incorporation of treated Flue Gas Desulphurization (FGD) by-products from the glass industry in Malaysia into non-stoichiometric cordierite compositions, focusing on its effects on the physical, mechanical, and microstructural properties. New ceramic samples were developed using a blend of kaolin, silica, talc, and treated FGD sludge. The results indicate that increasing the amount of treated FGD sludge leads to desirable properties such as a low thermal coefficient of expansion (2.62 – 3.64 x 10-6/ ℃), reduced density, and decreased average flexural strength (34.43 – 54.69 MPa), along with an increase in average porosity (17.04 - 31.90 %). Notably, ceramics that were treated with 3 wt% FGD sludge crystallized α-cordierite at a lower sintering temperature (1250 ℃), whereas traditional solid-state reaction methods need higher temperatures (>1350 ℃) to make α-cordierite. Overall, replacing feldspar with treated FGD sludge in non-stoichiometric cordierite formulations presents a sustainable strategy for recycling industrial waste and reducing the need for natural resources. The resulting materials exhibit characteristics suitable for lightweight construction applications, such as commercial bricks, due to their light weight, adequate flexural strength, and appropriate porosity.

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Formation of bio-based derived dicalcium silicate ceramics via mechanochemical treatment: physical, XRD, SEM and FTIR analyses

2023-07 , Siti Nur Hazwani Yunus , Khor Shing Fhan , Banjuraizah Johar , Nur Maizatul Shima Adzali , Nur Hazlinda Jakfar , Cheng Ee Meng , Emma Ziezie Mohd Tarmizi , Zainal Abidin Talib

Beta-dicalcium silicate plays an important role in modern technology, but its tendency for polymorphic transformation results in the dusting phenomenon, is a major challenge. Therefore, mechanochemical treatment is used to reduce the particle size to retain the stability of the polymorph. In this study, pure dicalcium silicate ceramics of β-monoclinic structure with P 121/c1 space group were synthesized using calcium oxide and silicate powders derived from calcined eggshells and rice husks, respectively. The powders were mixed in a 2:1 molar ratio by mechanochemical treatment and heat-treated in the air at temperatures ranging from 900°C to 1100°C for 2 h. The results reveal that pure betadicalcium silicate formed at 1100°C without adding stabilizers. The properties of the pristine and sintered bodies were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM). SEM revealed that the grain and pore sizes increase with rising sintering temperatures. FTIR spectra indicate the existence of Si-O bonds in -4 4 SiO tetrahedrons on all the samples. The sample sintered at 1000°C attains the lowest bulk density (1.2463 g/cm3), whereas the apparent porosity is the highest (62.5%). The reason for this trend is due to the decomposition of carbonate into CO2 gas. The densification onset for the sample sintered at 1100°C as the bulk density rises and grain size achieves 6.06 μm. This study further explains the effect of sintering temperatures on the physical, structural, and morphological properties of Ca2SiO4 which would also be useful for further optimization of its use.

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Dielectric spectroscopy technique for carbohydrate characterization of fragrant rice, brown rice and white rice

2017-11-20 , Cheng Ee Meng , Kok Yeow You , Lee KimYee , Abbas Z. , Hasliza A Rahim @ Samsuddin , Khor Shing Fhan , Zulkarnay Zakaria , Lee Y.S.

This study was conducted to investigate the feasibility of microwave dielectric spectroscopic technique in characterizing commercial rice due to different level of moisture content. There are some unethical rice industry runner mixes good qualities of rice which can be sold at high price with low cost and quality of rice to maximize profit. It causes fraudulency in business and great lost in term of money to nation who take rice as staple food. It happens frequently in Asian country which is active in agricultural activities. This technique is implemented using Keysight E8362B network analyzer in conjunction with an Keysight 85070E dielectric probe ranging from 200 MHz to 10 GHz. The samples of study are commercially available at market, namely fragrant rice, white rice, and brown rice, respectively. These are the popular and favorite rice for Malaysian due its delicacy and affordable price. Nutrient level for fragrant rice, white rice, and brown rice in terms of protein, moisture, carbohydrate and fat are different and unique. It leads to various electromagnetic responses toward frequency. Dielectric and reflection measurement were conducted to characterize these rice. The presence of polar and non-polar molecules in nutrient of rice causes variation of dielectric and reflection behavior over the operating frequency range.

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Mineral composition, crystallinity and dielectric evaluation of Bamboo Salt, Himalaya Salt, and Ba’kelalan salt content

2024 , Cheng Ee Meng , Che Wan Sharifah Robiah Mohamad , Nashrul Fazli Mohd Nasir , Khor Shing Fhan , Ong Hong Liang , Tan Xiao Jian , Lee Kim Yee , You Kok Yeow , Emma Ziezie Mohd Tarmizi , Mohd Riza Mohd Roslan , Siti Aishah Baharuddin

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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.

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Microwave dielectric analysis on adhesive disbond in acrylic glass (Poly (Methyl Methacrylate)) at KU-band

2020-10-01 , Cheng Ee Meng , Mohd A.R. , Shahriman Abu Bakar , Zuradzman Mohamad Razlan , You K.Y. , Nashrul Fazli Mohd Nasir , Mohd Shukry Abdul Majid , Khairul S.B. , 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.

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Nonlinear optical characterization of phosphate glasses based on ZnO using the Z-scan technique

2013-06-07 , Masoumeh Shokati Mojdehi , Wan Mahmood Mat Yunus , Khor Shing Fhan , Zainal Abidin Talib , N. Tamchek

The nonlinear optical properties of a phosphate vitreous system [(ZnO)x −(MgO)30−x −(P2O5)70], where x = 8, 10, 15, 18, and 20 mol% synthesized through the melt-quenching technique have been investigated by using the Z-scan technique. In the experiment, a continuous-wave laser with a wavelength of 405 nm was utilized to determine the sign and value of the nonlinear refractive (NLR) index and the absorption coefficient with closed and opened apertures of the Z-scan setup. The NLR index was found to increase with the ZnO concentration in the glass samples by an order of 10−10 cm2 ·W−1. The real and imaginary parts of the third-order nonlinear susceptibility were calculated by referring tothe NLR index (n2) and absorption coefficient (β) of the samples. The value of the third-order nonlinear susceptibility was presented by nonlinear refractive or absorptive behavior of phosphate glasses for proper utilization in nonlinear optical devices. Based on the measurement, the positive sign of the NLR index shows a self-focusing phenomenon. The figures of merit for each sample were calculated to judge the potential of phosphate glasses for application in optical switching.

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The Effect of the Amylose/Amylopectin Contents of Starch on Porosity and Dielectric Properties of the Porous Hydroxyapatite/Starch Composites

2020-07-09 , Chong You B. , Cheng Ee Meng , Abu Bakar S. , Nashrul Fazli Mohd Nasir , Eng Swee Kheng , Mohd Shukry Abdul Majid , Mohd Ridzuan Mohd Jamir , Khor Shing Fhan

This study aims to determine the effect of the amylose/amylopectin contents of starch on the porosity and dielectric properties of porous hydroxyapatite/starch composites. The porous hydroxyapatite/starch composites were prepared by utilizing the starches (rice, corn and potato starch) via gelatinization and retrogradation process. The complex permittivity of the porous hydroxyapatite/starch composites were evaluated in the frequency range of 12.4-18.0 GHz. The porous composites were exhibited the higher average porosity by using the starch with higher amylopectin content. The highly porous hydroxyapatite/starch composites with higher amylopectin content show the significant fluctuation peaks (at 13.8 and 16.6 GHz) and the higher imaginary part of the complex permittivity (ϵ′′) at higher frequency in the dielectric spectrum, respectively. The real (ϵ′) and imaginary part (ϵ′′) of the complex permittivity of the porous composites could be enhanced by increasing the average porosity and the amylopectin contents.

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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.

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Effect of multi-walled carbon nanotube loading on the dielectric properties of polylactic acid

2024-03-07 , Nur Azila Azahari , Mohd Ridzuan Mohd Jamir , Mohd Shukry Abdul Majid , Maslinda A.B. , Cheng Ee Meng , Khor Shing Fhan

Dielectric materials which capable to store charges are constantly being developed and improved for electronic applications such as in microelectronic integrated circuits (ICs). In this study, polylactic acid (PLA)/multiwalled carbon nanotube (MWCNT) composites are prepared and their dielectric properties are investigated. PLA/MWCNT composites have PLA as the matrix and MWCNT as filler with a loading of 1 wt%. The composites are porous composites achieved by using solvent casting and particulate leaching (SCPL) method. A frequency range of 1 kHz to 1 MHz is applied to measure the dielectric properties at room temperature. The PLA/MWCNT composites are categorized as low-k dielectric materials looking at the results of the dielectric test.

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