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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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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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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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Preparation of CdSe thin films: annealing effects on structure and optical properties
(2025-01-01)
Hankoy, Montree
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Kitiwan, Mettaya
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Tunthawiroon, Phacharaphon
In this work, we prepared well−crystallized CdSe thin films onto glass substrates using vacuum thermal evaporation method (VTE). The CdSe thin film was deposited on the substrate for 10 min in a vacuum chamber where the pressure was maintained at 5⋅10-5 Torr. To further increase the crystallinity, the as-deposited CdSe films were next thermally annealed in the air at annealing temperatures between 200 and 400 °C. The CdSe films were then investigated for phase composition, morphology, and optical properties. X-ray diffraction (XRD) examinations demonstrated a hexagonal phase of CdSe with preferential orientation along the (002) direction. The morphology analysis showed a homogeneous morphology with an average grain of approximately 65.55–90.25 nm in size. Chemical analysis confirmed the stoichiometric presence of Cd and Se. In addition, the optical band gap, determined from Tauc’s plot, using UV-Vis spectroscopic data, was found to be in the range of 1.66–1.69 eV. An annealing temperature of 300 °C resulted in the most favorable condition with the lowest optical band gap value of 1.66 eV, indicating a narrower band gap in the annealed CdSe thin film. The high deposition rate of VTE presents a significant advantage for this technique, potentially facilitating its use in creating optoelectronics and solar cells that are highly efficient and cost-effective.
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Enhancement of Flexural Strength in Fiber–Cement Composites through Modification of Sisal Fiber with Natural Rubber Latex and Expanded Perlite
(2024-04-01)
Thepruttana, Siriwan
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Patthanavarit, Jira
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Hankoy, Montree
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Kitiwan, Mettaya
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Keawprak, Nittaya
This study presents a novel approach in enhancing the flexural strength of sisal fiber cement composites by employing a dual coating technique with natural rubber latex and expanded perlite to the sisal fibers. The effects of different fiber content (0.25, 0.5, 0.75, 1, 1.25, and 1.5 wt%) and fiber length (1, 2, and 3 cm) on the physical and mechanical properties of sisal fiber cement were also studied. The physical properties, including bulk density and water absorption, were evaluated via the Archimedes method. Flexural strength was measured using the 3-point bending method, and microstructure was observed using a scanning electron microscope (SEM) and an optical microscope (OM). As the fiber content and length increase, the bulk density of the sisal fiber cement decreases. However, composites utilizing coated fibers consistently exhibit a higher bulk density than those utilizing uncoated fibers, attributed to enhanced adhesion and reduced porosity. The water absorption of sisal fiber cement increases with fiber content, but it is mitigated by the natural rubber latex coating, which prevents fiber–water absorption, and by expanded perlite, which reduces voids in the matrix. Composites containing coated fibers consistently exhibit superior flexural strength compared to those with uncoated fibers. The highest flexural strength values of 5.58 MPa were observed in composites utilizing 3 cm of coated fiber with 0.25 wt% fiber content. Microstructure analysis reveals a well-bonded interface in coated fibers, emphasizing the positive impact of coating on mechanical performance. The incorporation of coated sisal fibers effectively improves adhesion, water resistance, and flexural strength, offering sustainable and durable construction materials. The achieved results can serve as the guidelines for the development of a high-performance bio-based construction materials with improved durability and reduced environmental impact.
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Thin film nanocomposite nanofiltration with tannic acid-Fe(III) complexes functionalized Ti3C2Tx for enhanced divalent-salinity-water separation with a superior durability
(2024-02-01)
Deng, Yanan
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Zhang, Aihua
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Zhang, Zheng
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Xu, Yidan
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Li, Gaiye
Incorporating nanomaterials for a thin film nanocomposite (TFN) layer has been verified effective to improve the separation performance of nanofiltration (NF) membranes, whereas the poor compatibility between nanomaterials and polyamide (PA) matrix leads to a decrease in the salt rejection and pollution resistance. In this study, inspired by a new interface-bridging idea, Ti<inf>3</inf>C<inf>2</inf>T<inf>x</inf> was bonded with tannic acid-Fe(III) (TA-Fe(III)) complexes, and then incorporated into a PA matrix for the first time to obtain a novel TFN NF membrane. The introduction of TA-Ti<inf>3</inf>C<inf>2</inf>T<inf>x</inf> was found to effectively reduce the diffusion of piperazine, and thus result in the induction of a thinner, lower roughness, more hydrophilic, and defect-free PA layer. With the addition of 0.015 wt% TA-Ti<inf>3</inf>C<inf>2</inf>T<inf>x</inf>, the TFN membrane obtained the highest water permeability of 12.17 L m−2 h−1 bar−1, almost twice that of the pristine membrane, with a high Na<inf>2</inf>SO<inf>4</inf> rejection above 97 %. In addition, the TA-Ti<inf>3</inf>C<inf>2</inf>T<inf>x</inf>-filled TFN membranes were verified to exhibit excellent antifouling performance and pressure resistance with a high durability, which is crucial for the practical application in salinity water treatment. This study provides an effective strategy to tailor the interfacial microstructural of nanoparticle-filled NF membranes for superior divalent-salinity-water separation.
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Enhancing the hydrogen permeation of alumina composite porous membranes via graphene oxide addition
(2023-01-12)
Hankoy, Montree
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Phrompet, Chaiwat
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Ruttanapun, Chesta
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Kaewpengkrow, Prangtip Rittichote
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Vichaphund, Supawan
Graphene oxide (GO) membranes have attracted considerable interest for hydrogen (H<inf>2</inf>) purification applications. However, the addition of GO into matrix materials to enhance the efficiency of H<inf>2</inf> permeation remains a challenge. In this study, the fabrication of alumina/graphene oxide (AGO) composites containing varying contents of GO (0.5–3.0 wt.%) was investigated. The AGO composites were formed into pellets and sintered for 2 h at 1500 °C. Accordingly, the presence of GO in the membranes following sintering was confirmed by Raman spectroscopy. Additionally, the porosity of the AGO composites increased from 3.7% to 26.9% as the GO concentration increased from 0.5 wt.% to 3.0 wt.%. Furthermore, the average pore diameter of the AGO composites was in the range of 87–228 nm, and the pore size distribution was unimodal. The performance of the AGO membranes was investigated for the permeance of single gases H<inf>2</inf> and N<inf>2</inf> at 30–500 °C to evaluate their potential for H<inf>2</inf> separation applications. The AGO membranes with a GO addition of 2.5 and 3.0 wt.% exhibited a high hydrogen permeance of 232–410 × 10−6 mol m−2 s−1 Pa−1, which was approximately 10 times greater than that of pristine Al<inf>2</inf>O<inf>3</inf> membrane. Additionally, the ideal H<inf>2</inf>/N<inf>2</inf> selectivity values ranged from 4.02 to 4.20. Furthermore, gas permeation through the AGO membrane was observed to follow the Knudsen diffusion mechanism.
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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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EFFECT OF h-BN AS AN ADDITIVE ON PHYSICAL AND MECHANICAL PROPERTIES OF Al2TiO5 COMPOSITE
(2023-01-01)
Treetornkeerati, Paramapat
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Hankoy, Montree
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Kitiwan, Mettaya
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Rodchom, Mana
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Vichaphund, Supawan
Aluminum titanate (Al<inf>2</inf>TiO<inf>5</inf>) is a promising material for high-temperature applications due to its low thermal expansion, high melting point, and excellent corrosion resistance. In this study, the effect of h-BN addition on the properties of Al<inf>2</inf>TiO<inf>5</inf> composites was investigated. The composites were prepared by sintering a mixture of Al<inf>2</inf>O<inf>3</inf> and TiO<inf>2</inf> at a 1:1 molar ratio, with varying amounts of h-BN (5-20 mol%) added to the mixture. The samples were sintered at 1,500ºC for 4 h in N<inf>2</inf> atmosphere, and the bulk density, porosity, phase transition, microstructure, flexural strength, and hardness of the composites were investigated. XRD analysis confirmed the presence of Al<inf>2</inf>TiO<inf>5</inf>, Al<inf>2</inf>O<inf>3</inf>, and Al<inf>18</inf>B<inf>4</inf>O<inf>33</inf> phases in the composites. The addition of h-BN in increasing amounts from 5 to 20 mol% resulted in a gradual improvement in the bulk density, flexural strength, and hardness of the Al<inf>2</inf>TiO<inf>5</inf> composites. The composite with the highest h-BN content (20 mol%) exhibited a bulk density of 3.12 g/cm3, as well as the highest flexural strength and hardness values of 123.6±8.9 MPa and 11.2±4.1 GPa, respectively.

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