Ruttanapun, Chesta

Preferred name

Ruttanapun, Chesta

Alternative Name

Ruttanapun, C.

Main Affiliation

School of Science

chesta.ru@kmitl.ac.th

Now showing 1 - 10 of 46

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Loading effect of sol-gel derived barium hexaferrite on magnetic polymer composites
(2021-03-01)
Charoensuk, Thanida
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Thongsamrit, Wannisa
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Ruttanapun, Chesta
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Jantaratana, Pongsakorn
;
Sirisathitkul, Chitnarong
Solution–processing methods were investigated as viable alternatives to produce the polymer-bonded barium hexaferrite (BaM). BaM powders were first synthesized by using the sol-gel auto-combustion method. While the ignition period in two synthesis batches varied, the morphology of hexagonal microplates and nanorods, as well as magnetic properties, were reproduced. To prepare magnetic polymer composites, these BaM powders were then incorporated into the acrylonitrile-butadiene-styrene (ABS) matrix with a weight ratio of 80:20, 70:30, and 60:40 by using the solution casting method. Magnetizations were linearly decreased with a reduction in ferrite loading. Compared to the BaM loose powders and pressed pellet, both remanent and saturation magnetizations were lower and gave rise to comparable values of the squareness. The squareness around 0.5 of BaM samples and their composites revealed the isotropic alignment. Interestingly, the coercivity was significantly increased from 1727–1776 Oe in loose BaM powders to 1874–2052 Oe for the BaM-ABS composites. These composites have potential to be implemented in the additive manufacturing of rare-earth-free magnets.
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Synthesis of reduced graphene oxide quantum dots from graphene oxide via hydrothermal process and theirs structural, luminescence and magnetic properties
(2023-01-01)
Buatong, Nattha
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Ruttanapun, Chesta
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Sriwong, Chaval
Background: Reduced graphene oxide quantum dots (rGO-QDs) have attracted much interest because of its exceptional chemical and physical properties and novel applications in a new technology and devices such as, energy storage, electrochemical, photocatalysis, sensing, drug delivery, bioimaging and anticancer therapy. Methods: In this work, we reported a correlation study of the structural, morphological, luminescence and magnetic behavior of rGO-QDs as a function of hydrothermal reduction temperatures (such as 90 °C, 120 °C, 150 °C and 180 °C) of GO sheets precursor via hydrothermal process. GO precursor and the obtained rGO-QDs samples were confirmed and analyzed by several techniques such as, XRD, Raman, XPS, TEM, PL, UV–Visible, Fluorescence and EPR. Significant findings: Influence of hydrothermal cutting process with different temperatures (90 °C, 120 °C, 150 °C and 180 °C) on the evolution of structural, morphologies, luminescence and magnetic behavior for the changes of large GO sheets into ultra-small rGO-QDs is presented. XRD result confirmed the effect of increasing temperature on the hydrothermal cutting process which led to a decrease in D-spacing values of rGO-QDs products. While Raman results indicates the trend of I<inf>D</inf>/I<inf>G</inf> ratio decreases along with increasing hydrothermal reduction temperatures. XRS analysis revealed that the percentage of carbon content of GO precursor (∼64%) was shifted value to ∼83% for obtained rGO-QDs sample prepared at 180 °C. TEM images shown that a very thin plate-like shape with ultrasmall average diameter of rGO-QDs samples in rage of 22±2 nm to 8 ± 2 nm. The optical and PL results well-confirmed the characteristic quantum size effect of all rGO-QDs samples. Finally, the EPR signals indicate the crossover between paramagnetic and diamagnetic are depended on the reduction temperature. The rGO-QDs prepared at 180 °C do not give any EPR signal, signify the nonmagnetic nature. This indicate that the basal plane of rGO-QDs at 180 °C has nearly perfect sp2 network of graphene.
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Effect of rGO nanosheet loading in SiO2/rGO hybrid nanocomposites for enhancing optoelectrical, physical, and electrochemical properties
(2025-05-01)
Khammahong, Sunisar
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Phrompet, Chaiwat
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Ruttanapun, Chesta
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Sriwong, Chaval
In this study, silicon dioxide nanoparticles (SiO<inf>2</inf>NPs) mixed with reduced graphene oxide nanosheets (rGONS) and hybrid nanocomposites (S/rGOHNCs) were synthesized to study the opto-electrical, physical and electrochemical properties. S/rGOx%HNCs samples with rGONS at various loadings (10, 30, 50, and 70 wt%) were prepared SiO<inf>2</inf>NPs and rGONS suspensions in ultrasonication process by conventional heating. The SiO<inf>2</inf>NPs, rGONS and S/rGOx%HNCs were characterized and properties confirmed by XRD, Raman spectroscopy, FT-IR spectra, UV–Vis, SEM, EDX and TGA techniques. The electrical conductivity carrier concentration, energy gap, and dielectric constant increased with rGONS loading. The S/rGO30HNCs exhibited the highest thermal conductivity, 0.7 W/m·K, and Vickers microhardness, 41.0 HV. The value of electrochemical capacity of S/rGO70HNCs, 66.95 F/g, was due to the appropriate ratio of rGONS and SiO<inf>2</inf>NPs which significantly contributed to increasing redox reaction. The findings offered SiO<inf>2</inf>NPs mixed rGONS hybrid nanocomposites with enhanced optoelectrical (electrical, optical, dielectric), physical (mechanical, thermal) and electrochemical properties.
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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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Ferromagnetism of manganese-aluminium alloyed with 0–3% carbon from direct induction melting and subsequent annealing
(2020-01-01)
Charoensuk, Thanida
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Saetang, Panissa
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Ruttanapun, Chesta
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Phrompet, Chaiwat
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Pinitsoontorn, Supree
The transformation from ε to τ phase is investigated in manganese-aluminium (Mn<inf>55</inf>Al<inf>45</inf>) alloyed by the induction melting. By annealing Mn<inf>55</inf>Al<inf>45</inf> at 450–550°C for 2 h, the ferromagnetic τ-MnAl is enhanced at the expense of ε phase. The largest coercivity of 1139 Oe and remanent magnetization of 3.71 emu/g are obtained after annealing at 550°C. The additions of 1 and 2% carbon affect the phase and magnetic properties of Mn<inf>55</inf>Al<inf>45</inf> but the 2 h annealing at 550°C still leads to the largest coercivity. Interestingly, substantial coercivity and magnetizations are directly obtained in (Mn<inf>55</inf>Al<inf>45</inf>)<inf>98</inf>C<inf>2</inf> and (Mn<inf>55</inf>Al<inf>45</inf>)<inf>97</inf>C<inf>3</inf> by the induction melting without further heat treatments.
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Synthesis and electrochemical properties of activated lignite carbons-reduced graphene oxide nanocomposites symmetric supercapacitors
(2024-08-15)
Tuichai, Wattana
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Karaphun, Attaphol
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Phrompet, Chaiwat
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Chanlek, Narong
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Swatsitang, Ekaphan
Ultra-fast chargeable or rechargeable symmetric carbon-based supercapacitors (SCSs) with high capacity, inexpensive, and non-flammability have attracted much attention for electronics and energy storage devices. However, improving both high redox reaction and ion transport/diffusion processes by enhancing high energy storage performance and rapid ion/electron transport SCSs electrode materials remains challenging. Herein, we presented a successful preparation of activated lignite carbons-reduced graphene oxide (ALC-rGO) nanocomposite (NCp) with the ALC:rGO ratio of 80:20 wt% by a one-pot hydrothermal for high electrochemical performance. Importantly, the matrix of ALC-rGO NCp was primary amorphous carbon with hexagonal graphitic layers and pore structures of plentiful micropores and mesopores. Remarkably, the ALC-rGO NCp electrode exhibited a maximum specific capacitance (C<inf>sc</inf>) of 152.12 F/g at 0.5 A/g. Interestingly, the SCSs-ACL-rGO device could illustrate a good performance at a potential voltage of 1.8 V with C<inf>sc</inf> of 50.90 F/g at 1 A/g and capacity retention of 96.0 % at 5 A/g after 2,000 cycles GCD test.
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Investigating the High Electron Mobilities and Transport Scattering Processes in 2D Non-Van Der Waals Bi2O2Te Nanosheet Films
(2025-11-01)
Chomngam, Sasithorn
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Pimanpang, Samuk
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Ruttanapun, Chesta
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Rujisamphan, Nopporn
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Thongnum, Anusit
Bismuth oxytelluride (Bi<inf>2</inf>O<inf>2</inf>Te) nanosheets, a 2D non-van der Waals (2D-nvdW) semiconductor, has exceptionally high carrier mobilities, between 496 and 584 cm2V−1s−1 at room temperature (RT). Its numerous potential applications in multifunctional electronic devices have sparked much research interest. However, comprehensive explanations of the high RT mobilities and transport scattering processes in the Bi<inf>2</inf>O<inf>2</inf>Te nanosheet films are still sought. Herein, measured mobility data, between 5000 and 54,074 cm2V−1s−1 at 2 K and 125–584 cm2V−1s−1 at 300 K, are examined and modeled considering several scattering sources, including ionized impurities, longitudinal optical (LO) phonon, and electron–electron interactions. The total mobility based on three scattering mechanisms provided good quantitative agreement with the experimental results from thicknesses ranging from 21.0 to 55.0 nm. Ionized impurity scattering limits mobility at temperatures lower than 50 K, but LO phonon and electron–electron scatterings dominate at temperatures between 50 and 300 K. When the thickness decreases to 21.0 nm, electron-electron scattering strength becomes stronger and the RT mobility drops to 125 cm2 V−1s−1. These findings advance the knowledge of the charge transport mechanisms that underlie the Bi<inf>2</inf>O<inf>2</inf>Te nanosheet and provide more details for other 2D-nvdW and 2D semiconductors.
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Effect of graphene oxide on single fiber pullout behavior
(2021-04-19)
Chindaprasirt, Prinya
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Sukontasukkul, Piti
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Techaphatthanakon, Apisit
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Kongtun, Suriyawan
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Ruttanapun, Chesta
The properties of fiber reinforced concrete (FRC) depends strongly on bond between fiber and cement matrix. Any change in matrix and fiber characteristics affects the bond behavior. In this study, the effect of graphene oxide on cement composite strength and bond behavior between fiber and cement matrix was investigated. The graphene oxide solution with concentration of 10 mg/ml was mixed with cement mortar at 0.05% by weight of cement. Four types of fibers viz., hooked end steel, double hooked end steel, polypropylene and glass fibers were tested by embedding in both plain cement mortar (M) and cement graphene mortar (GM). The single fiber pullout test was performed at the rates of 60 and 180 mm/min. Results were collected in form of failure mode, scanning electron microscope (SEM) images, bond-slip response, bond strength and energy absorption. SEM images showed that the failure modes depended on fiber type, matrix type and loading rate. The steel fibers showed almost no damage except for the change of hooked end shape at the fiber end. For polypropylene fiber, the fiber surface scraping was commonly observed while the debonding of coating material was observed for glass fiber. The bond strength was higher in GM mortar than that of M mortar and increased with the increase in loading rate. In the case of fiber type, steel fibers exhibited higher bond and energy absorption than both polypropylene and glass fibers.
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A flow-circulation system incorporating a PVP-BiOBr@rGO assembly for simultaneous degradation and detection of oxytetracycline in fish farm wastewater
(2025-05-27)
Teerasong, Saowapak
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Suknakhin, Nichakarn
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Sonsaket, Thanamat
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Teerasong, Wanatchaporn
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Ruttanapun, Chesta
This work focuses on developing a new flow-circulation system for simultaneous detection and degradation of oxytetracycline (OTC) in fish farm wastewater to address a need for antibiotic abatement in wastewater treatment. Polyvinyl pyrrolidone capped bismuth oxybromide assembled with a reduced graphene oxide (PVP-BiOBr@rGO) photocatalyst was solvothermally synthesized and characterized. The prepared photocatalyst exhibited a morphological flower-like structure with a high surface area, 47.59 m2 g−1. Its band gap energy was 2.93 eV. A ternary PVP-BiOBr@rGO composite showed lower charge recombination than its pure form. PVP-BiOBr@rGO was filled inside a catalyst column of a flow system, with a spectrophotometer at the column end. Wastewater was continuously transported through the column and OTC spectrophotometrically examined during its degradation. The wastewater was recirculated until the OTC concentration was minimized. This system achieved 90.3% degradation of OTC within 180 min. The catalyst column could be regenerated for 2 cycles. The proposed flow system offers the advantages of ease of use, inline operation, and real-time sensing. This highlights a potential for real-world sustainable wastewater treatment applications.
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Topology of boron substitutional defects in single-walled carbon nanotubes: A first-principles study
(2024-06-01)
Prachamon, Wutthisak
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Jaiboon, Oruethai
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Komin, Sittipong
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Ruttanapun, Chesta
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Limpijumnong, Sukit
This is a theoretical study of boron-doped single-walled carbon nanotubes. The same topology of primitive nanodomains, located at different positions on single-walled carbon nanotubes, leads to different electronic band structures. We propose a ϕ term. Density functional theory was corrected for van der Waals interactions and used to carry out the periodic boundary condition geometry optimization, where boron formed the topologies of primitive nanodomains. The calculated bulk structure and local structure spectroscopic parameters can be used for comparison with experimental results to confirm the theoretical models.

Ruttanapun, Chesta

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