Wirunchit, Supamas
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Preferred name
Wirunchit, Supamas
Alternative Name
Wirunchit, S.
Main Affiliation
Email
supamas.wi@kmitl.ac.th
16 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, 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, Multi Self-cleaning Properties of Zinc Oxide Nanoparticles/ Polydimethylsiloxane (ZnO/PDMS) Composite on Polyester Textile(2023-03-02); - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Synthesis of ZnO nanoparticles by Ball-milling process for biological applications(2021-01-01); - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Study of nano Titanium (IV) oxide for Self-cleaning applications(2021-01-01); This research is study the fabrication of a composite film between Polydimethylsiloxane (PDMS) and Titanium (IV) oxide nanoparticles for self-cleaning applications via the spin coating process. This study has focused on the optimum ratio between PDMS and Titanium (IV) oxide and the optimum speed for the spin coating process, especially in order to obtain a composite film with outstanding self-cleaning surface properties. After that, the prepared composite films were studied by UV-Vis spectrometer, water contact angle measurement and solar simulator. Self-cleaning properties was investigated from the testing of wetting properties and measuring the water contact angle. Furthermore, the organic degradation properties were examined by degradation of methylene blue under UV light via solar. From this research was found that the PDMS/Titanium oxide (IV) at 4:3 ratio is the most optimum condition for the fabrication of a composite film by observing with the degradation of methylene blue has showed the highest the degradable efficiency is 55.59%. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, GREEN SYNTHESIS OF ZINC OXIDE NANOPARTICLES FROM LEMON PEEL EXTRACT AND THEIR ANTIBACTERIAL ACTIVITY(2024-01-01); ; - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Influence of Antimony Species on Electrical Properties of Sb-Doped Zinc Oxide Thin Films Prepared by Pulsed Laser Deposition(2023-06-01); ; ; This study systematically investigates the influence of antimony (Sb) species on the electrical properties of Sb-doped zinc oxide (SZO) thin films prepared by pulsed laser deposition in an oxygen-rich environment. The Sb species-related defects were controlled through a qualitative change in energy per atom by increasing the Sb content in the Sb<inf>2</inf>O<inf>3</inf>:ZnO-ablating target. By increasing the content of Sb<inf>2</inf>O<inf>3</inf> (wt.%) in the target, Sb<sup>3+</sup> became the dominant Sb ablation species in the plasma plume. Consequently, n-type conductivity was converted to p-type conductivity in the SZO thin films prepared using the ablating target containing 2 wt.% Sb<inf>2</inf>O<inf>3</inf>. The substituted Sb species in the Zn site (Sb<inf>Zn</inf><sup>3+</sup> and Sb<inf>Zn</inf><sup>+</sup>) were responsible for forming n-type conductivity at low-level Sb doping. On the other hand, the Sb–Zn complex defects (Sb<inf>Zn</inf>–2V<inf>Zn</inf>) contributed to the formation of p-type conductivity at high-level doping. The increase in Sb<inf>2</inf>O<inf>3</inf> content in the ablating target, leading to a qualitative change in energy per Sb ion, offers a new pathway to achieve high-performing optoelectronics using ZnO-based p–n junctions. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Electroreflectance study of antimony doped ZnO thin films grown by pulsed laser deposition(2021-10-01); ; In this research, antimony doped ZnO (SZO) thin films with various doping content have been grown on a c-Al<inf>2</inf>O<inf>3</inf> substrate by pulsed laser deposition. The effect of the applied electric field on the bandgap of SZO thin films was studied by electroreflectance (ER) spectroscopy using a capacitor-type geometry. Hall effect measurements indicate that the p-type conductivity of SZO is realized for the Sb<inf>2</inf>O<inf>3</inf> weight percentage at 2%. The blue shift of the energy bandgap was observed in thin films after increasing the doping concentration. The Burstein-Moss effect is the crucial mechanism for the blue shift of the SZO bandgap. Furthermore, we found the red shift of bandgap in all samples, which was measured under various electric fields by ER spectroscopy. The changes of the optical transition in the band structure should be the origin of the red shift behaviors of the SZO bandgap under the presence of the electric field. Based on our results, we can design and optimize the bandgap of SZO for optoelectronic devices.