Wirunchit, Supamas
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Preferred name
Wirunchit, Supamas
Alternative Name
Wirunchit, S.
Main Affiliation
Email
supamas.wi@kmitl.ac.th
25 results
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Item type:Publication, Green synthesis and optimized annealing tempserature effects on zinc oxide nanoparticles using mango peel extract(2026-01-01); ; Koetniyom, WantanaThis study presents the green synthesis of zinc oxide nanoparticles (ZnO-NPs) using mango peel extract (MgE) as a natural reducing and stabilizing agent. Phytochemical extraction was performed with deionized water, ethanol, and methanol for 1 h to 5 h, with deionized water at 4 h yielding the highest flavonoid content. Using zinc nitrate as a precursor, 25 mL of MgE successfully facilitated the synthesis of ZnO-NPs (ZnO-25MgE). It was found that annealing temperature at 400°C for 6 h produced pure ZnO. The obtained nanoparticles were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), and field emission scanning electron microscopy (FE-SEM). XRD confirmed the crystalline structure with an average size of 6.67 nm, while FT-IR and FE-SEM analyses revealed Zn–O vibrations, residual organics, and nanoscale morphology. Thermogravimetric analysis (TGA) indicated the appropriate annealing temperature for the removal of organics. For comparison, chemically synthesized ZnO was also characterized, and its antibacterial activity was assessed via disc diffusion against Escherichia coli and Staphylococcus aureus. The results demonstrated notable inhibition, highlighting the potential of biosynthesized ZnO-NPs for antimicrobial applications. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, The enhancement of sensitivity and response times of PDMS-based capacitive force sensor by means of active layer modification(2021-06-01); ; ; Jessadaluk, SukittiyaIn this work, sensitivity and response times of PDMS-based capacitive force sensors are enhanced via the modifications of the PDMS layer. Two modifying approaches are proposed; (i) change PDMS's (elastomer:curing agent) ratio and (ii) adding conductive polymer PEDOT:PSS into the PDMS layer. The change of PDMS (elastomer:curing agent) ratio from (10:1) to (30:1) increases the sensitivity from 0.4 0.08 to 0.72 0.23 kPa-1 (+80%) but it does not significantly affect the response/recovery times. In addition, by adding 1% wt. of PEDOT:PSS to PDMS (30:1), the further increment of sensitivity from 0.72 0.23 to 1.44 0.17 kPa-1 (+100%) and the shorter response time from 1.59 0.02 to 0.45 0.03 s (-72%) are observed. The mechanical and electrical studies reveal that the change of PDMS (elastomer:curing agent) ratio and the adding of PEDOT:PSS to PDMS layer result in the modification of PDMS's deformability and the increase of charge transportation, leading to the enhancement of sensing characteristics of the sensors. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Structural transformation in antiferroelectric PbZrO3-relaxor ferroelectric Pb(Ni1/3 Nb2/3)O3 solid solution system(2008-08-12); The solid solution between the antiferroelectric (AFE) PbZrO<inf>3</inf> (PZ) and the relaxor ferroelectric (FE) Pb (Ni<inf>1/3</inf>Nb <inf>2/3</inf>)O<inf>3</inf> (PNN) was synthesized by the columbite precursor method. The crystal structure, phase transformations, and dielectric and thermal properties of (1-x) PZ-xPNN where x=0.00-0.30 were investigated. With these data, the FE phase diagram between PZ and PNN has been established. The crystal structure data obtained from X-ray diffraction indicate that the solid solution PZ-PNN, where x=0.00-0.30, successively transforms from orthorhombic to rhombohedral symmetry with an increase in the PNN concentration. The AFE phase→FE phase transition occurs in compositions of 0.00≤x≤0.08. The AFE→FE phase transition shifts to lower temperatures with higher compositions of x. The FE phase temperature range width increases with increased PNN. Apparently the replacement of the Zr<sup>4+</sup> ion by Ni <sup>2+</sup>/Nb<sup>5+</sup> ions decreases the driving force for an antiparallel shift of Pb<sup>2+</sup> ions because they interrupt the translational symmetry and facilitates the appearance of a rhombohedral FE phase when the amount of PNN is higher than 8 mol %. © 2008 American Institute of Physics. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Physical properties and phase transitions in perovskite Pb[Zr 1-x(Ni1/3Nb2/3)x]O3 (0.0 ≤ x ≤ 0.5) ceramics(2008-06-21); - Some of the metrics are blocked by yourconsent settings
Item type:Publication, High temperature phases in the 0.98 PbZrO3 -0.02Pb (Ni 1/3Nb2/3) O3 ceramic(2009-07-09); ; Besser, M. F.The phase evolution with temperature in the 0.98 PbZrO<inf>3</inf> -0.02Pb (Ni<inf>1/3</inf>Nb<inf>2/3</inf>) O<inf>3</inf> ceramic was investigated with dielectric permittivity and polarization measurements, hot stage transmission electron microscopy, and high temperature x-ray diffraction. Below 190 °C, the ceramic is in the antiferroelectric phase with characteristic 1 4 { 110 } c superlattice diffractions. In this stage, typical antiferroelectric 180° domains were observed. Between 190 and 220 °C, an intermediate phase, which is characterized by 1 2 { 110 } c -type superlattice diffractions, was detected. Evidences are found to suggest that this intermediate phase is ferroelectric. The 1 2 { 110 } c -type superlattice diffraction persists even into the paraelectric phase above 220 °C. In addition, there exists an incommensurate phase between the low temperature antiferroelectric phase and the intermediate ferroelectric phase. © 2009 American Institute of Physics. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, ZnO Nanoparticles Synthesis and Characterization by Hydrothermal Process for Biological Applications(2023-05-01); Koetniyom, WantanaThis research is interested in the development of zinc oxide (ZnO) nanoparticle synthesis by hydrothermal precipitation solutions for biological applications. The synthesis of ZnO nanoparticles study from zinc nitrate (Zn(NO<inf>3</inf>)<inf>2</inf>) precursor under the three precipitator solutions consists of potassium hydroxide (KOH), sodium hydroxide (NaOH), and ammonium hydroxide (NH<inf>4</inf>OH), respectively. The synthesis of ZnO nanoparticles is investigated using the following techniques: X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and Raman spectroscopy techniques. The structure and size of the ZnO nanoparticles are analyzed by using a field emission scanning electron microscope (FE-SEM), and finally, the antibacterial efficacy of the ZnO nanoparticles is studied. The hydrothermal synthesis condition realizes that the smallest ZnO nanoparticles come from the zinc nitrate (Zn(NO<inf>3</inf>)<inf>2</inf>) precursor reacted with sodium hydroxide (NaOH) precipitator at 120 °C for 4 h. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Influence of Dragon Fruit Peels on the Synthesis of Antibacterial Nano Zinc Oxide (Nano-ZnO) via Green Synthesis Method(2026-05-20); ; This research focused on adding value to dragon fruit peel waste by utilizing it in the synthesis of antibacterial nano zinc oxide (Nano-ZnO) through a green synthesis process. In this study, all the dragon fruit peels were extracted using the solvent extraction technique with three different solvents (deionized water, ethanol, and methanol) for 1, 2, 3, 4, and 5 h, respectively. The amount of flavonoids from the extract was determined using UV-Vis spectrophotometer to obtain the optimum extraction time, which was 4 h for DI water as the solvent. Moreover, antibacterial Nano-ZnO was synthesized successfully by a green synthesis process using zinc nitrate Zn(NO3)2 and the extracts. The molecular vibrations as well as the crystal structure and morphology were investigated by Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy (Raman), X-ray diffraction (XRD), and field emission scanning electron microscopy (FE-SEM), respectively. Additionally, the antibacterial efficacy of the nano-zinc oxide samples was evaluated using disc diffusion method. Gram-positive bacteria (Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli) were the test agents. The research shows that the X-ray diffraction patterns of all synthesized ZnO nanoparticles (NPs) exhibited a wurtzite (hexagonal) crystal structure. FT-IR spectroscopy confirmed the presence of Zn-O stretching vibrations at approximately 500 cm⁻¹. Furthermore, the FE-SEM reveals that ZnO-yellow particles displayed spherical morphologies with an average particle size of 145 nm. At the same time, ZnO-White and ZnO-Red nanoparticles exhibited a combination of rod-like and elliptical morphologies, with average particle sizes of 168 nm and 321 nm, respectively. In addition, the antibacterial activity demonstrates effective inhibition against S. aureus and E. coli in all three ZnO nanoparticle conditions. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Modification of a photoanode by means of localized surface plasmon resonance from Au nanoparticles decorated on ZnO nanorods for photoelectrochemical applications(2019-01-01); - Some of the metrics are blocked by yourconsent settings
Item type:Publication, The phase evolution with temperature in 0.94PbZrO3-0. 06Pb(Mg1/2W1/2)O3 antiferroelectric ceramic(2010-09-10); ; - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Multi Self-cleaning Properties of Zinc Oxide Nanoparticles/ Polydimethylsiloxane (ZnO/PDMS) Composite on Polyester Textile(2023-03-02);