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 17

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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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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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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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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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Xps analysis of oxide formed on the surface of co-28cr-6mo-1si alloy oxidized at 550 ºc
(2020-01-01)
Tunthawiroon, Phacharaphon
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Kitiwan, Mettaya
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Wongpromrat, Patthranit
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Chiba, Akihiko
This work investigated the influence of oxidation durations on the formation of oxide on the surface of wrought Co-28Cr-6Mo-1Si alloy. The iso-thermal oxidation was individually performed in air at 550ºC for 4, 12 and 24 h. For comparison, the surface of the non-oxidized Co-28Cr-6Mo-1Si alloy was concurrently examined. The chemical compositions of the non-oxidized and oxidized alloys were principally analyzed via X-ray photoelectron spectroscopy (XPS). The XPS results revealed that the surface of the non-oxidized alloy enriched in Cr-oxide. After oxidation treatment, the Co-oxide, existing as Co2+ state was observed coexisting with two Cr-oxide states, Cr3+ and Cr4+. The low concentrations of Mo6+ were also observed on the oxidized alloy surface. With the increase in oxidation durations, the Co-oxide was suppressed by Cr-oxide. The XPS depth profile analysis indicated that the thickness of the oxide film increased with increasing the oxidation duration.
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A STUDY ON SiC SUSCEPTOR CONFIGURATION FOR MICROWAVE HYBRID HEATING
(2023-01-01)
Ngamkiatpaisan, Akawat
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Hankoy, Montree
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Kitiwan, Mettaya
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Keawprak, Nittaya
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Tunthawiroon, Phacharaphon
Microwave hybrid heating (MHH) is a novel method to enhance ceramic sintering at high temperatures. The heating mechanism by MHH involves two directions of heat transfer for materials: microwaves heat the sample from the inside out, while the susceptor provides conventional heating from the outside. This unique heating mechanism offers several advantages, including uniform heating, rapid sintering, and enhanced microstructure and properties of materials. This study investigates the configuration of silicon carbide (SiC) susceptors for microwave hybrid heating. The microwave oven (multi-mode, 2.45 GHz, 1.2 kW) was modified with a ceramic insulator housing to maintain the temperature in the chamber. The effects of different configurations of SiC susceptors and microwave powers on the heating rate and maximum temperature were investigated. SiC susceptor plates were placed in the microwave oven using 3 different configurations, and for each condition, the microwave power was varied at 40, 60, 80, and 100% (480, 720, 960, and 1,200 W). The temperature in the microwave chamber was recorded until it reached 900°C or after 30 min of heating. Using two plates of SiC susceptor at 100 % power resulted in the highest heating rate of 62°C/min to reach 925°C. The results of this study offer guidance for the selection of appropriate heating conditions for individual ceramic materials, which can lead to more effective sintering processes.
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Influence of Expanded Perlite on Pore Structure and Physical Properties of Lightweight Aggregates Derived from Red Clay
(2026-05-01)
Moolpradab, Paniti
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Hankoy, Montree
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Zhang, Jianfeng
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Keawprak, Nittaya
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Kitiwan, Mettaya
The utilization of locally sourced raw materials for lightweight aggregate (LWA) production has attracted increasing attention due to its potential for cost reduction and sustainable material development. This study investigates the effect of expanded perlite addition (10–40 wt%) on the physical, structural, and mechanical properties of LWAs derived from In Buri red clay, sintered at a relatively low temperature of 800 °C without a conventional high-temperature bloating process. X-ray diffraction (XRD) analysis revealed that quartz remained the dominant phase after sintering, with minor albite and residual illite, indicating limited phase transformation. Thermal analysis showed that major mass loss occurred below 600 °C, confirming that 800 °C is sufficient for removing volatile components. SEM observations demonstrated that increasing perlite content led to the development of a more porous and interconnected microstructure. As the expanded perlite content increased, the bulk density decreased from 1.31 to 0.80 g/cm3, while the apparent porosity and water absorption increased to 48.5% and 60.8%, respectively. Conversely, crushing strength decreased due to increased porosity. These results demonstrate that expanded perlite is an effective additive for tailoring the microstructure and performance of LWAs at low sintering temperature. The developed materials show strong potential for horticultural applications.
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Comparative study of vacuum arc-remelting and spark plasma sintering processes on microstructure and corrosion behavior of Cp-Ti for biomedical implant applications
(2025-11-01)
Kunbuala, Neeraphat
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Srirussamee, Kasama
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Phamornnak, Chinnawich
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Tunthawiroon, Phacharaphon
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Hankoy, Montree
Titanium (Ti) and its alloys are widely used for biomedical applications due to their excellent mechanical properties and biocompatibility. However, the selection of an appropriate manufacturing process is critical to ensuring the optimal performance of Ti-based implants. This study investigates the effects of two fabrication methods –vacuum arc remelting (VAR) and spark plasma sintering (SPS) – on the microstructure and corrosion behavior of commercially pure titanium (Cp-Ti). VAR-Ti ingots were fabricated using arc-melting with multiple remelting cycles, whereas SPS-Ti specimens were sintered from Ti powders under pressure and pulsed current in a high-vacuum environment. Both specimens were subsequently heat-treated at 800 °C and furnace cooled. Microstructural characterization revealed coarser grains and porosity in VAR-Ti, while SPS-Ti showed refined, uniform α-phase structures. Electrochemical tests, including OCP, polarization, EIS, and ICP-MS, indicated slightly enhanced corrosion resistance in SPS-Ti, attributed to its defect-free microstructure. XPS analysis confirmed TiO<inf>2</inf> surface formation on both samples. Additionally, both materials exhibited high ductility and excellent biocompatibility, with cell viability exceeding ISO 10993-5 thresholds. These findings highlight the advantage of SPS in producing defect-minimized Cp-Ti with improved corrosion behavior for biomedical applications.
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Effect of expanded perlite on physical and mechanical properties of cement mortar
(2021-09-15)
Patthanavarit, Jira
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Kitiwan, Mettaya
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Keawprak, Nittaya
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Tunthawiroon, Phacharaphon
This study presents an investigation of the physical and mechanical properties of the cement mortar containing expanded perlite as a filler material. The effects of perlite replacement contents and compressive molding force on bulk density, water absorption, and flexural strength were observed. In the mixture of mortar, the content of sand was replaced with perlite ranging from 0 to 15% by weight. The specimen was pressed under the uniaxial force varied from 20 to 40 kN then de-molded and cured in the humidity for 28 days. With the increase in perlite content from 0 to 15 wt%, the bulk density decreased from 2118 kg/m3 to 1586 kg/m3 while the water absorption increased from 7.4% to18.7%. All composites showed a low thermal conductivity in the range of 0.10-0.27 W/m K. The specimen without perlite had a flexural strength in the range of 10.7-14.2 MPa, while that of sample containing perlite was 7.8-12.5 MPa. The cement mortar composite containing 10 wt% expanded perlite and molding at 40 kN showed the highest flexural strength of 12.50±1.36 MPa while the bulk density and water absorption were 1773 kg/m3 and 1.40 %, respectively. The results of this research can be used as a guideline for further development in building materials such as lightweight roof tile, lightweight brick, and ceiling tile.
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Development of Sustainable Biomaterials Composites from Waste Materials (Spent Mushroom Compost, Garlic Shell, and Water Hyacinth) with Edible Mushroom Mycelium-Based
(2026-01-01)
Kitiwan, Mettaya
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Tangthirasunun, Narumon
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Tunthawiroon, Phacharaphon
Purpose: To evaluate performance and add value of bio-based degradable waste materials of spent mushroom compost cooperate with garlic shell, and water hyacinth with mushroom mycelium-based methods. Method: The Ganoderma lucidum, Lentinus polychrous, L. squarrosulus, and Pleurotus sajor-caju were used to study bio-based composites from various formula of waste materials (spent mushroom compost (Agrocybe cylindracea or P. ostreatus), garlic shell, and water hyacinth). Then we selected the best species and the formula of biomaterial composites to prepare pot prototypes. Finally, the biomaterial composite pots were measured physical and mechanical properties. Results: L. squarrosulus exhibited the fastest mycelial growth and highly effective to composed materials. Then, selected further pot prototypes with variation formulation and physical and mechanical properties were presented; density ranged from 0.18−0.22 g cm-3 and water absorption reaching between 172−250% in 24 hr., the absorption increases more gradually, reaching 302%−368% after 168 hr. Variations between formulation, the composites AC-F1 and PO-F1 exhibited superior water absorption. Whereas composites AC-F2 and PO-F2 demonstrated the lowest water absorption. For the compressive strength significant differences between samples prepared with spent mushroom compost from A. cylindracea and P. ostreatus. The spent mushroom compost from P. ostreatus is higher compressive strength, ranging from 385.4−451.5 kPa. In contrast the spent mushroom compost derived from A. cylindracea ranged between 174.9−197.3 kPa. Conclusion: The mycelium-based biodegradable composite produced demonstrates excellent performance and suitability for various applications. As such, they contribute to efficient upcycling and support zero-waste practices.

Kitiwan, Mettaya

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