KMITL

Permanent URI for this communityhttps://dspace.kmitl.ac.th/handle/123456789/1

Browse

Search Results

Now showing 1 - 10 of 15

Some of the metrics are blocked by your
consent settings
Synthesis of ZIF-8 powders and their electrochemical role as a protective layer minimizing dendrite formation and elevating anode stability in Zn-ion batteries
(2025-12-01)
Chananil, Patompong
;
Triosod, Sureerat
;
Phumuen, Phatcharin
;
Chanlek, Narong
;
Kumnorkaew, Pisist
A Zn-based metal-organic framework (Zn-MOF) was synthesized via a solvothermal process using Zn(NO<inf>3</inf>)<inf>2</inf>·6H<inf>2</inf>O and 2-methylimidazole (2-Hmim) in ethanol at 120 °C for 24 h, yielding a crystalline structure consistent with ZIF-8, exhibiting a high surface area (1820.73 m2 g−1) and a large pore size (1.47 nm). The ZIF-8 powder was coated onto a Zn plate (ZIF-8@Zn) and evaluated as a Zn-ion battery anode, demonstrating significantly enhanced cycling stability, with a lifespan up to 200 h across all current densities, outperforming bare Zn (132, 49, 34, 36, and 20 h for 1–5 mA cm−2) in a 2 M ZnSO<inf>4</inf> electrolyte. Post-plating/stripping analysis revealed that ZIF-8@Zn maintained a smooth morphology, whereas bare Zn exhibited pronounced roughness and dendrite formation. Cross-sectional SEM images confirmed a swollen ZIF-8 layer with reduced Zn thickness at higher plating/stripping current densities, and XRD analysis detected Zn<inf>4</inf>SO<inf>4</inf>(OH)<inf>6</inf>·4H<inf>2</inf>O and Zn<inf>4</inf>SO<inf>4</inf>(OH)<inf>6</inf>·5H<inf>2</inf>O byproducts on both electrodes. The ZIF-8@Zn| |V<inf>2</inf>O<inf>5</inf> full-cell exhibited superior capacity (314.03 vs. 251.75 mAh g−1 at 100 mA g−1) and long-term stability, with a 22.71 % capacity increase after 1000 cycles, in contrast to an 11.52 % reduction in the Zn| |V<inf>2</inf>O<inf>5</inf> cell, highlighting ZIF-8@Zn's potential for stable Zn-ion batteries.
Some of the metrics are blocked by your
consent settings
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
;
Suknakhin, Nichakarn
;
Sonsaket, Thanamat
;
Teerasong, Wanatchaporn
;
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.
Some of the metrics are blocked by your
consent settings
Influence of a Non-ionic Surfactant on the Release of Rhodamine B from Poly(vinyl) Alcohol/Polyoxalate/Span-80 Composite Nanofibers Prepared by Emulsion Electrospinning
(2024-10-26)
Phromviyo, Nutthakritta
;
Chompoosor, Apiwat
;
Teerasong, Saowapak
Controlling drug release using a nanocomposite method is crucial; however, burst release must be avoided in order to obtain effective controllable drug release. In this study, poly(vinyl) alcohol/polyoxalate/Span-80 (PVA/ POX/ Span-80) composite nanofibers loaded with Rhodamine B were produced using emulsion electrospinning. The objective of this work was to evaluate the cooperative roles of POX and Span-80 on nanofibrous scaffold stability and drug release regulation by monitoring Rhodamine B release performance from electrospun composite nanofibers. The microstructure and hydrophilic properties of the emulsion electrospun nanofibers were studied using scanning electron microscopy (SEM), water contact angle, and swelling tests. According to the results, increasing the POX content had a significant effect on the size of nanofibers. The water contact angles increased as the POX content increased. The release of Rhodamine B was governed by a two-stage diffusion mechanism that was greatly influenced by PVA/POX ratios and Span-80. To compare release behavior, non-emulsion electrospun nanofibers without Span-80 were prepared as control samples. Emulsion nanofibers were found to release at a slower rate than non-emulsion nanofibers. The in vitro release profiles revealed that Rhodamine B was released from emulsion electrospun fibers in a sustainable manner and that no initial burst release was observed. These findings imply that emulsion electrospun nanofibers can potentially be used to deliver drugs, nutraceuticals, and fragrances in a prolonged manner.
Some of the metrics are blocked by your
consent settings
Preparation of PVP-BiOBr Adsorbent for Efficient Indigo Carmine Dye Removal Using Flow-Circulation Systems
(2024-07-09)
Teerasong, Saowapak
;
Saenghirun, Thanakrit
;
Sunthornchainukul, Thanawat
;
Thammaso, Supinya
;
Chompoosor, Apiwat
This work presents an adsorptive removal of indigo carmine (IC) dye using a polyvinylpyrrolidone capped bismuth oxybromide (PVP-BiOBr) adsorbent. PVP-BiOBr was synthesized via a simple precipitation method. The morphology and surface chemical structure of the adsorbent were characterized using XRD, SEM, FTIR, and BET analyses. The adsorption isotherm and kinetics were investigated to reveal the mechanism of dye removal. Prepared PVP-BiOBr has a crystallite size of 19.7 nm, with a mean particle size of ∼2 μm and a surface area of 5.14 m2 g-1. The optimum pH for this adsorptive process spanned the range of 4 to 9. Experimental data indicated applicability of the Langmuir isotherm model, and the study confirms a pseudo-second-order kinetics model. The maximum adsorption capacity for IC dye was 208.3 mg g-1. A flow-circulation system was developed for the treatment of IC dye contaminated water samples. PVP-BiOBr was packed inside a column and did not spill into the water sample after treatment. The removal efficiency was ≥90% after 25 min. The PVP-BiOBr adsorbent could be reused for three cycles. This work demonstrates that PVP-BiOBr is a promising candidate as an adsorbent for IC dye removal. Additionally, the flow-based system establishes an automated operation in continuous mode, which is viable for large scale applications.
Some of the metrics are blocked by your
consent settings
Enhanced Stability of Gold Nanoparticles with Thioalkylated Carboxyl-Terminated Ligands for Applications in Biosensing
(2024-06-14)
Ngernpimai, Sawinee
;
Puangmali, Theerapong
;
Kopwitthaya, Atcha
;
Tippayawat, Patcharaporn
;
Chompoosor, Apiwat
Gold nanoparticles (AuNPs) are widely recognized for their remarkable optical and chemical properties, making them versatile materials with diverse applications in sensing, catalysis, and biomedical fields. However, their susceptibility to aggregation and poor dispersion under different environmental stresses limits their utility in practical applications. In this study, we investigate the efficacy of utilizing carboxylate-terminated ligands to stabilize AuNPs and enhance their stability and functionality. Through a series of experiments, including assessments of pH buffer effects, ionic strength variations, freeze-drying stress, and protein adsorption, we demonstrate the effectiveness of these ligands in maintaining the stability of AuNPs within a pH range of 5-10. This enables them to resist aggregation in the presence of high concentrations of electrolytes and facilitates rapid redispersion after freeze-drying, enabling long-term storage of AuNPs in a dry powder form without compromising their stability or functionality. Moreover, the ligands efficiently prevent nonspecific protein binding. We explore application of these stabilized AuNPs conjugated with specific monoclonal antibodies for detection of Listeria monocytogenes, highlighting their potential for use in biosensing applications. This research underscores the significance of carboxylate-terminated ligands in stabilizing AuNPs, offering insights into the development of reliable and functional nanomaterials for various biomedical and biosensing applications.
Some of the metrics are blocked by your
consent settings
The Evaluation of a Lateral Flow Strip Based on the Covalently Fixed “End-On” Orientation of an Antibody for Listeria monocytogenes Detection
(2024-05-28)
Thongmee, Patsara
;
Ngernpimai, Sawinee
;
Srichaiyapol, Oranee
;
Mongmonsin, Urairat
;
Teerasong, Saowapak
In this study, the covalently fixed “end-on” orientation of a monoclonal Listeria monocytogenes antibody (mAb-Lis) to amino terminated oligo (ethylene glycol)-capped gold nanoparticles (NH<inf>2</inf>-TEG-AuNPs) was used to fabricate an in-house lateral flow strip (LFS), namely, the fixed “end-on” Lis-mAb-NH-TEG-AuNPs LFS. The aim was to evaluate the performance of the fixed “end-on” Lis-mAb-NH-TEG-AuNPs LFS in detecting L. monocytogenes. The proposed LFS enabled the sensitive detection of L. monocytogenes in 15 min with a visual limit of detection of 102 CFU/mL. Quantitative analysis indicated an LOD at 10 CFU/mL. The fixed “end-on” Lis-mAb-NH-TEG-AuNPs LFS showed no cross-reactivity with other pathogenic bacteria and practical performance across different food matrices, including human blood, milk, and mushroom samples. Furthermore, the clinical performance of the fixed “end-on” Lis-mAb-NH-TEG-AuNPs LFS for detecting L. monocytogenes was evaluated by using 12 clinical samples validated by the hemoculture method. It demonstrated excellent concordance with the reference methods, with no false-positive or false-negative results observed. Therefore, the fixed “end-on” Lis-mAb-NH-TEG-AuNPs LFS serves as a promising candidate for a point-of-care test (POCT), enabling the rapid, precise, and highly sensitive detection of L. monocytogenes in clinical samples and contaminated food.
Some of the metrics are blocked by your
consent settings
Hydrothermal transforming phase structure and chemical composition of V2O5 for elevating electrochemical property of zinc ion batteries
(2024-05-01)
Triosod, Sureerat
;
Phakkhawan, Authit
;
Phumuen, Phatcharin
;
Wanabut, Wassana
;
Chanlek, Narong
V<inf>2</inf>O<inf>5</inf> was hydrothermally modified in NaOH or KOH solutions at 180 °C for 24 h. The NaOH-modified powders had a nanorod-like structure with a crystal structure matching Na<inf>2</inf>V<inf>6</inf>O<inf>16</inf>·nH<inf>2</inf>O. The TG/DTA results of Na<inf>2</inf>V<inf>6</inf>O<inf>16</inf>·nH<inf>2</inf>O powders show a mass reduction of 4.24 % at 300 °C, corresponding to n of 1.496. KOH-modified powders have large rods and irregular structures with a crystal structure matching KV<inf>3</inf>O<inf>8</inf>. Its TG/DTA spectrum shows a very small percentage change, just 0.37 % at 600 °C. Cyclic voltammetry (CV) curves of a Na<inf>2</inf>V<inf>6</inf>O<inf>16</inf>·nH<inf>2</inf>O cathode in a 2 M ZnSO<inf>4</inf> electrolyte exhibit higher oxidation and reduction current densities than those of pure V<inf>2</inf>O<inf>5</inf> and KV<inf>3</inf>O<inf>8</inf> electrodes.The best capacity of a Na<inf>2</inf>V<inf>6</inf>O<inf>16</inf>·nH<inf>2</inf>O electrode is 296.10 mAh g-1 at a current density of 50 mA g−1, which is higher than those of pure V<inf>2</inf>O<inf>5</inf> (102.90 mAh g-1) and KV<inf>3</inf>O<inf>8</inf> (91.07 mAh g-1) electrodes. EDS and XPS results reveal that the charge and discharge states involve de-insertion and insertion of Zn2+ ions out of/into the electrodes. Computational analysis of Zn intercalation into V<inf>2</inf>O<inf>5</inf>, Na<inf>2</inf>V<inf>6</inf>O<inf>16</inf>·nH<inf>2</inf>O, and KV<inf>3</inf>O<inf>8</inf> structures displays increasing electron density on neighboring V atoms, which explains the increasing V4+/V5+ ratio in the discharged state as evidenced by XPS spectra.
Some of the metrics are blocked by your
consent settings
Effect of GeI2 and GeBr2 incorporation on perovskite properties and performance of carbon-based perovskite solar cells
(2023-04-01)
Aunping, Namfon
;
Kumlangwan, Pantiwa
;
Towannang, Madsakorn
;
Chanlek, Narong
;
Kumnorkaew, Pisist
CH<inf>3</inf>NH<inf>3</inf>PbI<inf>3</inf> (MAPbI<inf>3</inf>) film was prepared by a convective method, and its X-ray diffraction spectrum displays the tetragonal perovskite structure. GeI<inf>2</inf> and GeBr<inf>2</inf> powders dissolve poorly in a mixed dimethylformamide-dimethylsulfoxide (DMF-DMSO) solvent, but the introduction of 5 wt% 5-ammonium valeric acid iodide (5-AVAI) into the mixed DMF-DMSO solvent greatly promotes GeI<inf>2</inf> and GeBr<inf>2</inf> solubility. XRD spectra of the (5-AVAI)MAPbI<inf>3</inf>, MAGe<inf>x</inf>Pb<inf>1–x</inf>I<inf>3</inf>, and MAGe<inf>x</inf>Pb<inf>1–x</inf>Br<inf>2x</inf>I<inf>3–2x</inf> (x = 0.0625 and 0.125) films exhibit a tetragonal perovskite structure, but the film morphologies become rougher than that of the pristine MAPbI<inf>3</inf> film. Discontinuous islands are formed on MAGe<inf>x</inf>Pb<inf>1–x</inf>I<inf>3</inf> and MAGe<inf>x</inf>Pb<inf>1–x</inf>Br<inf>2x</inf>I<inf>3–2x</inf> (x = 0.125) films. X-ray photoemission spectroscopy (XPS) analysis detected the Ge element on all Ge-doped films. The best performance levels of the carbon-based hole transport layer-free MAGe<inf>x</inf>Pb<inf>1–x</inf>I<inf>3–x</inf> (x = 0.0625, η= 3.63%) and MAGe<inf>x</inf>Pb<inf>1–x</inf>Br<inf>2x</inf>I<inf>3–2x</inf> (x = 0.0625, η = 2.95%) perovskite solar cells are lower than that of the pristine MAPbI<inf>3</inf>–based perovskite solar cell (η = 5.28%). This is likely due to the increased surface roughness, pin-holes, isolated islands, and the decreased light absorbance of the Ge-doped films in comparison with the pristine MAPbI<inf>3</inf> film.
Some of the metrics are blocked by your
consent settings
Insight into the Covalently Oriented Immobilization of Antibodies on Gold Nanoparticle Probes to Improve Sensitivity in the Colorimetric Detection of Listeria monocytogenes
(2022-11-16)
Ngernpimai, Sawinee
;
Srijampa, Sukanya
;
Thongmee, Patsara
;
Teerasong, Saowapak
;
Puangmali, Theerapong
In this work, the covalently oriented conjugation of monoclonal Listeria monocytogenes antibody (mAb-Lis) to amino-terminated oligo(ethylene glycol)-capped gold nanoparticles (NH<inf>2</inf>-TEG-AuNPs) was studied. After NH<inf>2</inf>-TEG-AuNPs were synthesized, the amino-terminated ligands on the particles were then linked to the carboxyl groups in the mAb-Lis through EDC/NHS chemistry. By maintaining the pH of the solution at ∼5, the Fc region of the antibody could preferably attach to the particle surface, providing a specific Fab region that was available for binding with the target pathogen. The resulting mAb-NH-TEG-AuNPs could act as a colorimetric probe for L. monocytogenes based on a particular antigen-antibody interaction, which resulted in a drastic aggregation of particles. This caused the color of the colloidal solution to transition from red-pink to purple or even gray depending on the pathogen concentration. To perform quantitative analysis, the absorbance ratio of A<inf>650</inf>/A<inf>534</inf>was monitored as a function of L. monocytogenes concentration using a spectrophotometer. The detection limit was very low at 11 CFU/mL. Furthermore, a lateral flow strip (LFS) was fabricated as a portable device for onsite utilization. LFS detection could be completed by the naked eye and by a smartphone. The detection limit of LFS was estimated to be 103CFU/mL. Our methods exhibited a substantial improvement in sensitivity compared to that of previous studies on immuno-based nanoparticles. The assay could be completed in 15 min, and no cross reactivity by any pathogen was found. Hence, the designed AuNPs exhibit great promise for use in monitoring L. monocytogenes for food safety and in other applications.
Some of the metrics are blocked by your
consent settings
A new mechanism for resonance Rayleigh scattering detection of minoxidil based on catalytic oxidation of silver nanoparticles
(2022-07-05)
Teerasong, Saowapak
;
Praditweangkum, Wiboon
;
Chompoosor, Apiwat
This work presents a new method for minoxidil detection based on silver nanoparticle (AgNP) oxidation. Minoxidil, which is a pyrimidine N-oxide, can be reduced to its corresponding pyrimidine via a redox reaction. In this system, acetate buffer serves as a proton source. AgNPs act as electron donors that contribute electrons to the reaction, producing Ag+. Consequently, the sizes and numbers of AgNPs in the system decrease, which results in a decline in their resonance Rayleigh scattering (RRS). By monitoring the RRS intensity at 409 nm, a change in intensity was linearly related to the minoxidil concentration over a concentration range of 0.5 – 5.0 mM. The detection limit was 0.35 mM. This approach is simple and rapid. It is done by directly mixing the drug and AgNPs in an acidic buffer. The reaction was completed within 2 min. This proposed method was successfully utilized for quantification of minoxidil in topical hair-growth formulations.

KMITL

Browse

Filters

Settings

Sort By

Results per page

Search Results