Mekprasart, Wanichaya
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Mekprasart, Wanichaya
Alternative Name
MEKPRASART, Wanichaya
Mekprasart, W.
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wanichaya.me@kmitl.ac.th
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Item type:Publication, X-ray characterization, structural analysis, antibacterial activity, and self-cleaning property of Cu-doped TiO2-SiO2 nanocomposite prepared by sonochemical process(2024-12-01); ;Songpanit, Maneerat ;Sanyen, Thanyapa ;Samart, SutichaiTiO<inf>2</inf>-SiO<inf>2</inf> nanocomposites with different copper (Cu) precursor loadings were prepared by a one-step sonochemical process. The mole ratio of Cu precursor in TiO<inf>2</inf>-SiO<inf>2</inf> composite was varied at 0.004, 0.008, 0.020, and 0.040, respectively. The specific X-ray characterization techniques on crystalline structure, chemical composition, and chemical states of Cu-doped TiO<inf>2</inf>-SiO<inf>2</inf> composite were carried out by X-ray diffraction technique (XRD), X-ray fluorescence (XRF), and X-ray photoelectron spectroscopy (XPS), respectively. Surface morphology and chemical bonding of Cu-doped TiO<inf>2</inf>-SiO<inf>2</inf> composite were monitored by field emission scanning electron microscope (FE-SEM) and Fourier transform infrared spectrophotometer (FTIR). For antibacterial properties, the inhibition zone of antimicrobial activity was investigated by varying amounts of Cu precursors in the TiO<inf>2</inf>-SiO<inf>2</inf> composite. After that, Cu-doped TiO<inf>2</inf>-SiO<inf>2</inf> composite powder with different Cu precursor ratios was mixed in PMMA solution and deposited on glass slides to study the optical property and hydrophilicity by UV-VIS-NIR spectrophotometer and contact angle method. XRD patterns of Cu-doped TiO<inf>2</inf>-SiO<inf>2</inf> nanocomposites show the formation of the main TiO<inf>2</inf> anatase phase with the ultrafine particles observed by FE-SEM images. FT-IR spectra of the composites are assigned to the prominent peaks of the Ti-O-Ti and Ti-O-Si bond relating to the TiO<inf>2</inf>-SiO<inf>2</inf> host matrix. Meanwhile, TiO<inf>2</inf>-SiO<inf>2</inf> composites with Cu precursor at 0.004 mol ratio can significantly enhance the antibacterial activity with a large inhibition zone. The contact angle value of Cu-doped TiO<inf>2</inf>-SiO<inf>2</inf> nanocomposite film at 0.040 Cu precursor mole ratio in the TiO<inf>2</inf>-SiO<inf>2</inf> matrix resulted in the optimized composite ratio for achieving a hydrophilic surface on the substrate. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, ZnO nanostructures synthesized by one-step sol-gel process using different zinc precursors(2024-01-01) ;SONGPANIT, Maneerat; ; Zinc oxide (ZnO) nanopowders have been widely applied in electronics, optics and photocatalytic applications depending on their morphological structure. In the bottom-up process, it is conceived that the different zinc precursors may result in different formations of ZnO nanostructures with exceptional morphology. This work focuses on ZnO material synthesized via the facile sol-gel synthesis using different zinc slat precursors, including zinc acetate, zinc nitrate, zinc sulphate, and zinc chloride. All zinc salt precursors were incorporated with sodium hydroxide and hexamethylenetetramine (HMTA) under mild thermal energy with consistent conditions to investigate ZnO formation. The as-prepared samples appeared in white powders with different aggregation features. The crystalline phase, surface morphologies, and element mapping of all ZnO samples were analyzed using X-ray diffraction technique (XRD) and field emission scanning electron microscope (FE-SEM). The chemical bonding structure of ZnO powders was characterized by Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy. The specific surface area per volume of ZnO nanopowders obtained by different zinc salt precursors was analyzed by Brunauer-Emmett-Teller (BET) method. All ZnO samples obtained from various zinc salt precursors exhibited a high crystallinity of the wurtzite structure without other impurities. The structural properties of ZnO nanopowders demonstrated different sizes and structures with distinguished formation and aggregation depending on the zinc precursor basic strength being used. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Effect of nitrogen doping on optical and photocatalytic properties of TiO2 thin film prepared by spin coating process(2013-01-01); ;Khumtong, Thanakorn ;Rattanarak, Jiravat ;Techitdheera, WicharnNitrogen-doped TiO<inf>2</inf> thin films were prepared by spin coating on glass substrate. Different amount of nitrogen doped in TiO<inf>2</inf> matrix was 0, 3 and 10%. As-obtained films were annealed at 400°C for 2 h. The optical and photocatalytic properties of N-doped TiO<inf>2</inf> thin films were analyzed via UV-Vis spectrophotometry. The chemical properties were investigated by Fourier transform infrared spectrometer and Raman spectroscopy. When doping TiO<inf>2</inf> with nitrogen, its absorption spectrum is shifted to visible region resulting to the enhancement of photocatalyst properties in dye photodegradation. Raman and FTIR patterns show that N-doped TiO<inf>2</inf> pattern is still identical to undoped TiO<inf>2</inf> pattern resulting to unsubstitutation of nitrogen atom in Ti-O bonding. © 2013 The Authors. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Characterization and x-ray absorption spectroscopy of ilmenite nanoparticles derived from natural ilmenite ore via acidassisted mechanical ball-milling process(2017-09-01) ;Phoohinkong, Weerachon ;Pavasupree, Sorapong ;Wannagon, Anucha ;Sanguanpak, SamunyaIn this work activated ilmenite nanoparticles were prepared by chemical-assisted in mechanical ball-milling process from ilmenite ore as starting raw material. The effect of milling process on their phase composition, particle size, surface morphology and local structure were investigated. Phase identification and crystalline structure of ilmenite mineral, milled samples and subsequent leached residues were characterized by x-ray diffraction (XRD). Meanwhile, the distorted octahedral structure and the oxidation state of relevant elements in ilmenite ore and activated ilmenite obtained by different process conditions were analyzed by x-ray absorption spectroscopy (XAS). Particle size and morphologies of the samples were monitored by field emission scanning electron microscope (FESEM) and transmission electron microscope (TEM). Three dominant peaks of TiO2 rutile, FeTiO<inf>3</inf>, and Fe<inf>2</inf>TiO<inf>4</inf> are obviously adulterated in XRD patterns after mechanical milling with water and acid solution when comparing to precursor mineral. However, the contaminated phase of FeTiO3 and Fe<inf>2</inf>TiO<inf>4</inf> was readily decreased by acid-assisted mechanical ball-milling. The enhancement in leaching process of ilmenite residue after milling can be obtained with sulfuric acid. This result suggests that iron contaminated phase could be leached from the sample resulting to the decrease in Fe environment around Ti atom. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Glucose Conversion to 5-(Hydroxymethyl)furfural (5-HMF) using Microwave Radiation and Titanium Dioxide(2022-01-01); ; ;Boonyarattanakalin, SiwaruttIn this project, the focus is placed on the reaction optimizations to produce 5-hydroxymethylfurfural (5-HMF), a common chemical building block to other industrially useful derivatives. The main objective of this study is to determine the feasibility of using different forms of TiO<inf>2</inf> as a catalyst to acquire 5-HMF from monosaccharides by an efficient, economical, and environment-friendly process. The use of three different forms of TiO<inf>2</inf> (anatase, rutile, and P-25) as a catalyst, for the glucose dehydration process in this study, has never been reported in past literature. The heating by microwave radiation is introduced to the reaction, which requires elevated temperature, to reduce both the required reaction time and temperature. TiO<inf>2</inf>, the heterogeneous catalyst for the dehydration mechanism, was filtered off, while the 5-HMF dissolved and stayed in the aqueous solution. The three TiO<inf>2</inf> catalyst forms are separately utilized to optimize reaction conditions. Anatase form is shown to be the most effective at catalyzing the dehydration process. The reaction temperature of 187 ºC; anatase as a catalyst; and reaction time of 5 minutes led to the optimal outcome in this project. The maximum 5-HMF yield obtained in this study is 12.84%, which is in-between the 6.10-18.60% 5-HMF yield range acquired by Qi et al., 2008. Moreover, a catalyst/substrate weight ratio of 1:10 was used in this study, compared to the 1:2 ratio used by Qi et al., 2008. Hence, this project reduced the amount of catalyst required to obtain a significant 5-HMF yield, and successfully demonstrated that the anatase form of TiO<inf>2</inf> is a viable catalyst for the dehydration of monosaccharides to 5-HMF. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, The Effect of Polyvinyl Alcohol Addition on the Optical Properties and Oxygen Detection Performance of Titanium Dioxide and Methylene Blue Nanocomposite Colorimetric Indicators(2024-05-01); ;Rattan, Praphaporn ;Songpanit, Maneerat; Okumura, HideyukiIn this study, we investigated the impact of polyvinyl alcohol (PVA) incorporation on the optical properties and oxygen detection performance of a titanium dioxide/methylene blue (TiO<inf>2</inf>/MB) nanocomposite colorimetric indicator for packaging applications. The nanocomposite was synthesized via mechanical milling of TiO<inf>2</inf> nanoparticles with MB and citric acid. PVA, at varying concentrations (0, 3, 9, and 14 wt%), was introduced during the wet milling process to produce a homogeneous composite film. Spin coating was employed to fabricate TiO<inf>2</inf>/MB nanocomposite films for oxygen detection evaluation. The influence of PVA loading on the films’ chemical functionalities and surface morphologies was assessed using Fourier-transform infrared spectroscopy (FTIR) and field-emission scanning electron microscopy (FE-SEM). The indicator’s activation process, involving a color change between bleached and colored states, and its recovery time were monitored via optical imaging and UV-VIS-NIR spectrophotometry. The results revealed that a PVA content of 9 wt% yielded well-defined films with enhanced stability of the TiO<inf>2</inf>/MB nanocomposite’s oxygen detection performance. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Transparent light-guided plates based on TiO2/Rhodamine6G composite thin films(2016-11-25); Transparent light-guided plates for solar cell application from nano-titanium dioxide (TiO<inf>2</inf>), rhodamine 6G (R6G) and poly methyl methacrylate (PMMA) composite films were prepared by spin coating technique on glass substrates. Effects of the annealing temperatures and times on the formation of the TiO<inf>2</inf> crystalline film that acted as an initial model for the light-scattered layer in solar concentrators were investigated. Physical and morphological properties of the TiO<inf>2</inf> film were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and atomic force microscope (AFM). After the annealing process, TiO<inf>2</inf> films obviously formed in the anatase phase with the enlarged crystallite size and the high rough surface by the increase of the annealing temperature and the treating time. Meanwhile, the optical properties of the TiO<inf>2</inf> thin films were analyzed via a UV–Vis spectrophotometer. The transparency of the film was significantly affected by the annealing temperature and the aging time. Moreover, the light scattering performance of the TiO<inf>2</inf> layer cooperated with Rhodamine6G in the PMMA matrix as the preliminary model of light-guide plate was investigated by fluorescence spectra. Strong light emission from the light-guide plate could be significantly enhanced by the existence of the TiO<inf>2</inf> crystalline layer acting as the scattering film. Optimized performance of the planar light-guide plate incorporated with Rhodamine6G dye and the light-scattered TiO<inf>2</inf> layer was obtained from the film annealed at 500 °C for 5 h. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Tailoring the Emission Behavior of WO3 Thin Films by Eu3+ Ions for Light-Emitting Applications(2023-01-01) ;Kavitha, V. S. ;Biju, V. ;Gopchandran, K. G. ;Praveena, R.Jayasankar, C. K.The article reports the successful fabrication of Eu<sup>3+</sup>-doped WO<inf>3</inf> thin films via the radio-frequency magnetron sputtering (RFMS) technique. To our knowledge, this is the first study showing the tunable visible emission (blue to bluish red) from a WO<inf>3</inf>:Eu<sup>3+</sup> thin film system using RFMS. X-ray diffractograms revealed that the crystalline nature of these thin films increased upto 3 wt% of the Eu<sup>3+</sup> concentration. The diffraction peaks in the crystalline films are matched well with the monoclinic crystalline phase of WO<inf>3</inf>, but for all the films’, micro-Raman spectra detected bands related to WO<inf>3</inf> monoclinic phase. Vibrational and surface studies reveal the amorphous/semi-crystalline behavior of the 10 wt% Eu<sup>3+</sup>-doped sample. Valence state determination shows the trivalent state of Eu ions in doped films. In the 400–900 nm regions, the fabricated thin films show an average optical transparency of ~51–85%. Moreover, the band gap energy gradually reduces from 2.95 to 2.49 eV, with an enhancement of the Eu<sup>3+</sup>-doping content. The doped films, except the one at a higher doping concentration (10 wt%), show unique emissions of Eu<sup>3+</sup> ions, besides the band edge emission of WO<inf>3</inf>. With an enhancement of the Eu<sup>3+</sup> content, the concentration quenching process of the Eu<sup>3+</sup> ions’ emission intensities is visible. The variation in CIE chromaticity coordinates suggest that the overall emission color can be altered from blue to bluish red by changing the Eu<sup>3+</sup> ion concentration. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Indium Tin Oxide conductive nanoparticles synthesized by sonochemical method(2016-10-12) ;Noonuruk, Russameeruk ;Kanoksinwuttipong, Jiruntanin; ;Techitdheera, WicharnSritharathikhun, JaranThis work reports the synthesis of Indium Tin Oxide (ITO) nanoparticles via sonochemical process at various calcination temperature using InCl<inf>3</inf> and SnCl<inf>4</inf>·5H<inf>2</inf>O as starting precursors for In and Sn sources, respectively. The crystal structure properties of the samples were investigated by X-ray diffraction. Meanwhile, the size, shape and microstructure of the particles were observed by field emission scanning electron microscope and chemical composition was investigated by energy dispersive X-ray Spectrophotometer. The corresponding optical band gap was determined by diffuse reflectance spectra. The XRD results showed that the as-prepared powders were initially formed in amorphous phase and the crystalline structure of powders were obtained after calcination beyond specific temperature. The correlated reactions and mechanisms during sonochemical process responsible for ITO formation are suggested. The comparison between ITO powders prepared by sonochemical process and co-precipitation process is additionally carried out and the results show significant differences in their morphology and crystallite sizes of the particles. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Physical, electrical and optical properties of F/Sb Codoped SnO2 synthesized via sonochemical process(2016-01-02) ;Noonuruk, R.; ; ;Sritharathikhun, J.F/Sb-codoped SnO<inf>2</inf> nanoparticles were synthesized via sonochemical process using stannic chloride pentahydrate (SnCl<inf>4</inf>·5H<inf>2</inf>O) as host precursor while antimony(III) chloride (SbCl<inf>3</inf>) and ammonium fluoride (NH<inf>4</inf>F) were chosen as Sb and F dopant precursors, respectively. Their physical properties and morphologies were investigated using X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy and transmission electron microscope while their electrical and optical properties were investigated by Hall measurement and diffuse reflectance spectroscopy. As-synthesized powder of polycrystalline phase SnO<inf>2</inf> nanoparticles can be obtained by one-step sonochemical process and its crystallinity can be improved by calcination process. The formation of crystalline phase of SnO<inf>2</inf> is assisted by cavitation effect provided by intense ultrasonic radiation via rapid collision. The characterization results disclose that Sb dopant has strong influence on both physical and electrical properties while F dopant provide considerable effect on electrical property of the samples. It is noticed that the codoping of both elements with certain contents can significantly heighten its electrical conductivity.
