Kitiwan, Mettaya

Preferred name

Kitiwan, Mettaya

Alternative Name

Kitiwan, M.

Main Affiliation

School of Science

mettaya.ki@kmitl.ac.th

Now showing 1 - 10 of 30

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Optical Properties of CuCdS Thin Film Prepared by Vacuum Thermal Evaporation Technique
(2023-01-01)
Hankoy, Montree
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Treetornkeerati, Paramapat
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Fungfuang, Natasia
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Khlayboonme, S. Tipawan
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Kitiwan, Mettaya
This study reports on the synthesis and characterizations of copper cadmium sulfide (CuCdS) thin films prepared using the vacuum thermal evaporation technique with copper sulfide and CdS as precursors in a 1:1 molar ratio. The structural properties of the thin films were analyzed using X-ray diffraction (XRD) which revealed that the main composition of the thin film was CdS with the preferred orientation of the (101) plane. The optical properties were examined using UV–Vis spectrophotometry. The photosensitivity of the films was determined using I–V measurements performed with a two-probe technique. The prepared CuCdS thin films have high optical transmittance of 92%.
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Positive ionic conduction of mayenite cement Ca12Al14O33/nano-carbon black composites on dielectric and thermoelectric properties
(2020-03-01)
Rudradawong, Chalermpol
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Kitiwan, Mettaya
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Goto, Takashi
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Ruttanapun, Chesta
Mayenite Ca<inf>12</inf>Al<inf>14</inf>O<inf>33</inf>/nano-carbon black composites (C12A7/nCB) were investigated regarding the mechanism of oxygen ion vacancy in the extra cage framework of positive ionic transport in thermoelectric and dielectric properties. The oxygen ion vacancy in C12A7/nCB composites was produced from C12A7 composited with nano-carbon back (nCB) for 0, 1, 3, 5 and 10 wt% by the rapid spark plasma sintering. The C12A7/nCB samples were characterised by X-ray diffraction (XRD), UV–vis spectroscopy, Raman spectroscopy, Scanning electron microscopy (SEM), Transmission electron microscopy (TEM) and UV–vis spectroscopy. The O− <inf>2</inf> ions vacancy was confirmed by Raman spectrum. The positive ionic conduction was verified by the positive sign of Seebeck coefficient. The ionic conductivity was in order 5 S/cm of C12A7/nCB of 10 wt% content. The thermal conductivity was reduced by the effects of the O− <inf>2</inf> ions vacancy as point defect. The ZT for thermoelectric materials of C12A7/nCB of 10 wt% content were in a range from 0.01 × 10−3 to 0.16 × 10−3, respectively. Positive ion conduction of C12A7/nCB composites resulting from oxygen ion vacancy occupying in extra framework affected to enhance dielectric constant, Seebeck coefficient, electrical conductivity and reduce thermal conductivity.
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Effects of AlN on the reactive sintering of porous Al2TiO5composites
(2020-01-01)
Kitiwan, Mettaya
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Kongsak, Mongkol
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Atong, Duangduen
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Wakui, Yoshito
The porous Al2TiO5/Al2O3 composites were fabricated by reactive sintering at 1500-1700 °C in nitrogen atmosphere. The starting materials Al2O3 and TiO2 were mixed in an equimolar ratio and the addition of AlN was 5-40 mol%. The effects of AlN content and sintering temperature on phase composition, linear shrinkage, pore sized distribution, porosity and microstructure were investigated. The XRD results showed that the composites mainly consist of Al2TiO5 while the peak intensity of Al2O3 increased with AlN content. The median pore sizes decreased with increasing AlN content and were in the range of 2- 6 lm, 1-2 lm, 0.4-0.7 lm, and 0.3-0.5 lm for composites using 10, 20, 30, 40 mol% AlN, respectively. The porosities of ATN10 and ATN20 were from 20% to 10% at 1600 °C to 1700 °C while the porosities of ATN30 and ATN40 were almost constant in between 11 and 13%. The addition of AlN effectively decrease the grain size of Al2TiO5 and led to reduce microcrack at the grain boundary.
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Effect of AlN addition on the reaction sintering of Al2TiO5 composites fabricated by spark plasma sintering
(2023-01-01)
Kitiwan, Mettaya
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Atong, Duangduen
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Endo, Fumio
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Goto, Takashi
Fully dense Al<inf>2</inf>TiO<inf>5</inf>–Al<inf>2</inf>O<inf>3</inf>–TiN (ATN) composites were fabricated by reactive sintering using spark plasma sintering at 1400°C for 5 min under 100 MPa in vacuum. An equimolar ratio of Al<inf>2</inf>O<inf>3</inf>:TiO<inf>2</inf> was used as the starting powder, while the addition of 0–36 mol% AlN was investigated. The thermodynamic calculation indicates that the initial reaction was that of TiO<inf>2</inf> and AlN, forming TiN and Al<inf>2</inf>O<inf>3</inf>, and then the remaining TiO<inf>2</inf> reacted with Al<inf>2</inf>O<inf>3</inf> to produce Al<inf>2</inf>TiO<inf>5</inf>. With the increase in AlN precursor, Al<inf>2</inf>TiO<inf>5</inf> gradually decreased, while Al<inf>2</inf>O<inf>3</inf> and TiN increased. The lattice parameters of Al<inf>2</inf>TiO<inf>5</inf> were enlarged with AlN addition, implying the incorporation of N atoms in the Al<inf>2</inf>TiO<inf>5</inf> unit cell. The addition of AlN effectively produced fully densified bodies with small grain size, and microcrack-free, which therefore enhanced the mechanical properties of ATN composites. At 36 mol% AlN addition, the composite shows Vickers hardness and fracture toughness of 16.26 ± 1.61 GPa and 5.20 ± 0.46 MPa.m1/2, respectively.
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Fabrication and characterization of lightweight aggregates with expanded perlite and NPK nutrient incorporation
(2025-06-01)
Rungrueng, Panadda
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Hankoy, Montree
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Kitiwan, Mettaya
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Keawprak, Nittaya
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Tunthawiroon, Phacharaphon
This study focuses on the development of porous lightweight aggregates incorporated with NPK fertilizer as a sustainable nutrient carrier for agricultural applications. The integration of expanded perlite (EP) as a pore-forming agent enabled the production of lightweight aggregates (EP-LWAs) at lower sintering temperatures (900 °C) while maintaining high porosity and water absorption properties, reducing energy consumption compared to conventional high-temperature ceramic processing. The optimized EP-LWAs exhibited a bulk density of 1.15 g/cm3, porosity of 46.09 %, and water absorption of 40.28 %, ensuring enhanced nutrient retention capacity. The fertilizer incorporation process was achieved using a simple vacuum infiltration technique, effectively loading the pellets with 1.2 % nitrogen (N), 2.6 % phosphorus (P), and 1.2 % potassium (K), surpassing typical soil nutrient levels and exhibiting comparable NPK content to organic fertilizers. These results highlight the potential of EP-LWAs as an energy-efficient and eco-friendly planting materials, offering a cost-effective for sustainable agriculture, green roof, and vertical gardening applications.
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Dry film Holographic grating based on computer-generated mask Lithography
(2022-01-01)
Inneam, Chanikan
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Tipawan Khlayboonme, S.
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Kitiwan, Mettaya
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Yindeesuk, Witoon
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Srinuanjan, Keerayoot
This paper presented an alternative technique for fabricating the dry film holographic grating based on a mask generated by computer simulation and experimental results. The mask was generated by a fringe pattern which is created by the mathematical model of two beams interference with various angles. Computer simulation of the fringe pattern was printed on film, i.e., the holographic grating mask. The mask was attached on dry film and then illuminated by UV light, where the lithography technique was applied. According to the lithography technique, the computer-generated holographic grating mask was transferred to dry film. After fabrication, fringe patterns obtained from the grating were observed. Then, the grating period was analyzed and confirmed by Scanning Electron Microscope (SEM). Experimental results show that the method could apply to fabricate the dry film holographic grating.
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Modification of Al2O3-Based Membranes with Carbon Black for Enhanced Hydrogen Permeation
(2025-11-01)
Hankoy, Montree
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Rodchom, Mana
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Vichaphund, Supawan
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Atong, Duangduen
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Zhang, Jianfeng
This work presents the development and characterization of alumina–carbon black (ACB) composite membranes for enhanced hydrogen separation performance. A series of membranes containing 0–3.0 wt.% carbon black was fabricated via high-temperature sintering and systematically investigated with respect to their structural, morphological, mechanical, and gas separation properties. The addition of carbon black significantly influenced membrane microstructure, promoting pore network formation, increasing specific surface area, and enhancing gas transport. Gas permeation tests using H<inf>2</inf> and N<inf>2</inf> revealed that all ACB membranes exhibited higher hydrogen permeance than the pure Al<inf>2</inf>O<inf>3</inf> membrane. Notably, the ACB3.0 specimen demonstrated the highest H<inf>2</inf> permeance of 508 × 10−6 mol m−2 s−1 Pa−1 at 303 K, which is nearly four times greater than the unmodified membrane. At an elevated temperature (773 K), H<inf>2</inf>/N<inf>2</inf> selectivity improved with increasing carbon black content, with ACB3.0 achieving a maximum selectivity of 3.82, exceeding the theoretical Knudsen value, suggesting a synergistic contribution of Knudsen diffusion and surface diffusion. These results demonstrate that carbon black is a cost-effective and versatile additive for modifying ceramic membranes, offering a promising route for advancing hydrogen purification technologies in industrial applications.
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Microwave-activated reduced graphene oxide composite with hydrothermally treated corn husk activated carbon as an active electrode for high electrochemical performance in symmetrical carbon-based supercapacitor devices
(2026-07-01)
Srakaew, Khattiya
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Ratchayotee, Pornthip
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Janorat, Phattharawadee
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Phrompet, Chaiwat
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Kitiwan, Mettaya
This work applies microwaves for synthesizing reduced graphene oxide (rGO) and waste material corn husk activated carbon composites as active electrode materials for symmetric supercapacitors. The rGO is activated by microwave treatment and corn husk carbon by KOH in processed hydrothermal activation, followed by compositing at various weight ratios. Among all compositions, rGO:H_Corn_C (90:10) is reported with the best properties, with a specific surface area of 314.2 m2/g and a high specific capacitance of 1152 F/g at 0.1 A/g. The optimized composite also delivered increasing energy and power densities of up to 160 Wh/kg and 9.68 × 102 W/kg, respectively, within a 1 V operating window. In an experiment by assembling a symmetric coil cell supercapacitor, the device showed a specific capacitance of 142.23 F/g at 0.1 A/g, cycling stability with 98.8% capacitance retention after 1000 cycles of charge-discharge, and peak energy and power densities of 40.68 Wh/kg and 5.74 × 102 W/kg. Overall, the composite material with a high content of rGO and corn husk-derived activated carbon prepared by the hydrothermal method exhibits high-performance for the material in supercapacitor applications.
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Characterization of oxide films on wrought Co–Cr–Mo–xSi alloys exposed to high-temperature oxidation
(2021-10-01)
Tunthawiroon, Phacharaphon
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Kitiwan, Mettaya
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Srirussamee, Kasama
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Li, Yunping
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Yamanaka, Kenta
Co-based alloys are currently being used in a wide range of high temperature applications owing to their high resistance to oxidation and corrosion. However, their oxidation-induced degradation could still occur during the long-term exposure to high temperature. Thus, the continuous development of oxidation-resistant Co-based alloys is of crucial importance. In this research, the influence of Si addition on the oxidation behavior of Co–Cr–Mo–xSi alloys under the isothermal oxidation treatment at 700 °C in air was investigated. The Si concentration (x) was varied from 0.1 to 5.0 wt.%. Surface morphologies and chemical compositions of the oxide films formed were analyzed by using SEM-EDS and XPS. The chemical compositions obtained from the surface analysis revealed that Si has played a role in the stabilization of Cr oxides on the surface of Co–Cr–Mo–xSi alloys. With increasing Si concentration, Co-oxide formation on the alloy surface was suppressed by the presence of Cr-oxide due to the selective oxidation of Cr atoms. Furthermore, SiO<inf>2</inf> was both found along the grain boundaries and interfaces between the outmost oxide layer and matrix. It was also found that the oxide thickness was reduced with increasing Si concentration. This was a result of the formation of stable Cr-oxide and SiO<inf>2</inf> sub-layer that became a barrier inhibiting the inward and outward diffusion of O and Cr.
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Reversible thermally stimulated phase transition in amorphous–nanocrystalline β-V2O5 thin films for temperature-sensitive electronics
(2026-01-01)
Tipawan Khlayboonme, S.
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Fungfuang, Natasia
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Kitiwan, Mettaya
V<inf>2</inf>O<inf>5</inf> thin films are significant for next-generation temperature-sensitive electronic devices owing to notable phase stability and reversibility. Optimizing phase characteristics toward reversible low-temperature transitions enhances device performance. In this study, thin films of amorphous–nanocrystalline β-V<inf>2</inf>O<inf>5</inf> were deposited on glass substrates using the inclined magnetron head in radio-frequency magnetron sputtering under an O<inf>2</inf> reactive gas. The effects of thermal stimulation (heating to 400 °C, followed by cooling) were investigated for an as-deposited film prepared at 7.5 % O<inf>2</inf> and for two annealed films deposited at 7.5 % and 10 % O<inf>2.</inf> The annealed films were annealed at 300 °C before thermal stimulation. The films were characterized by X-ray diffractometry (XRD), Auger-electron spectroscopy, field-emission electron microscopy, Van der Pauw and Hall effect measurements, and ultraviolet–visible spectroscopy. The as-deposited film exhibited insulating behavior, whereas the annealed films at 7.5 % and 10 % O<inf>2</inf> demonstrated n-type and p-type conductivities, respectively, accompanied by decreased intensity of the V LMM Auger peak. Before thermal stimulation, the as-deposited film was highly amorphous, whereas the annealed films comprised the β-monoclinic phase. Thermal stimulation caused mixed β-monoclinic and β-tetragonal symmetries for all films and induced significant changes in surface morphology, except for the annealed film at 7.5 % O<inf>2</inf>. Variations in carrier density and bandgap energy indicated that thermal energy promoted oxygen vacancies but reduced vanadium vacancies in the film structure. In situ XRD analysis demonstrated the phase stability and reversible formation of the nanocrystalline β-monoclinic phase, revealing potential for thermally responsive applications requiring repeatable phase behavior.

Kitiwan, Mettaya

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