Sriwong, Chaval
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Item type:Publication, Effect of synthesized Ag nanoparticles by using the different amounts of polyvinylpyrrolidone for Ag-natural rubber hybrid sheets and their antibacterial properties(2017-01-01); Ag-natural rubber (Ag-NR) hybrid sheets were successfully prepared with a very simple and low cost method. In this method, silver nanoparticles (AgNPs) were firstly synthesized by a rapid and green microwave-assisted using polyvinylpyrroridone (PVP) media. The effect of PVP weight ratios towards the size of AgNPs was also investigated. Then, Ag-NR hybrid sheet samples were prepared by latex mixing-casting method using concentrated natural rubber (NR) latex with the synthesized AgNPs colloids. The characteristic absorption, particles sizes and shapes of the obtained AgNPs were examined through UV-vis, TEM and SAED. Also, the prepared Ag-NR sheet samples were characterized using XRD, FT-IR, SEM and EDS techniques. It was found that the particles sizes of all the synthesized AgNPs had spherical-like shape, and the mean sizes were increased from 29.7 to 90.4 nm upon increasing PVP contents. EDS results showed the AgNPs were well-dispersed and impregnated into the rubber matrix. Moreover, the antibacterial properties of the prepared Ag-NR sheets were tested by agar disk-diffusion method with Gram-positive and Gramnegative bacteria as Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli), respectively. The results showed that the hybrid sheets exhibited excellent antibacterial properties against these bacteria, in which the zones of inhibition were also dependent on the synthesized AgNPs by utilizing the different amounts of PVP. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Dielectric and electrochemical properties of hybrid Pt nanoparticles deposited on reduced graphene oxide nanoparticles /poly (vinylidene fluoride) nanocomposites(2021-06-01); Nano-sized platinum (Pt) materials deposited on reduced Graphene Oxide (rGO) nanosheets (hybrid Pt-rGO nanoparticle) were prepared by the seed-mediated growing process using 20 wt% of Pt nanomaterials in rGO suspension. Dielectric properties of hybrid Pt-rGO nanoparticles/poly (vinylidene fluoride) nanocomposites (Pt-rGO/PVDF nanocomposites) were synthesized by a liquid–phase assisted dispersion and hot–pressing methods with different volume fractions (f) of hybrid Pt-rGO nanoparticle loading PVDF nanocomposites. The observed particle size of Pt nanomaterials deposits on rGO nanosheets was 5 nm. The dielectric constant (ε′) of Pt-rGO/PVDF nanocomposites was increased with increasing hybrid Pt-rGO nanoparticle. The volume fraction f<inf>Pt-rGO</inf> ≈0.0786 exhibited excellent ε′ ≈ 86 with very low loss tangent (tanδ) ≈ 0.021 at 1 kHz. High dielectric properties of Pt-rGO/PVDF composite should be ascribed to combination of the micro-capacitor and Maxwell–Wagner–Sillars (MWS) effects. Electrochemical properties of specific capacitances (C<inf>sc</inf>) and capacity retention of hybrid Pt-rGO nanoparticle electrode were investigated by the cyclic voltammetry and the galvanostatic charge-discharge. Interestingly, the hybrid Pt-rGO nanoparticle electrode displayed maximum C<inf>sc</inf> value of 169.8 F g<sup>−1</sup> at the current densities of 0.25 A g<sup>−1</sup>. This was due to the occurrence of various oxygen functional groups in the rGO- and Pt<sup>+</sup> ions as contributing to form of pseudo-capacitance in hybrid Pt-rGO nanoparticle. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Facile and green synthesis of Melamine-Formaldehyde@rGO foam with enhanced superhydrophobicity for oil removal application(2021-01-01) - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Enhancing the supercapacitor performance of NiCo2O4 microflowers by reduced graphene oxide nano-sheets(2021-01-28); ; This work presented the preparation and supercapacitor performance of a spinel nickel-cobalt oxide (NiCo2O4) microflowers mixed with nano-sized reduced graphene oxide (rGO) sheets. The hybrid material (NiCo2O4/rGO), pure NiCo2O4 and nano-sized rGO samples were characterized and confirmed by several techniques, such as XRD, SEM and EDS. The supercapacitive properties of all prepared samples were also studied using an electrochemical measurement technique (CV and GCD). The results revealed that the NiCo2O4/rGO (484.1 F.g<sup>-1</sup>) hybrid electrode exhibited much higher specific capacitance than those of pristine NiCo2O4 (358.3 F.g<sup>-1</sup>) and nano-sized rGO (113.8 F.g<sup>-1</sup>) electrodes, respectively. Hence, this work indicates that the supercapacitor performance of NiCo2O4 mixed rGO hybrid materials is more superior to the pure NiCo2O4 microflowers and nano-sized rGO sheets. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Effecting on electrical performance of Methylammonium Lead Chloride Iodide perovskite films composited by reduced graphene oxide for controlling double Schottky barrier(2024-06-01); Ruttanapan, ChestaSemiconducting perovskite thin films are cheap to fabricate and can be coated on fluorine-doped tin oxide (FTO) substrates by using simple techniques such as the solution deposition method. In this work, we show that the improved electrical performance of perovskite film produces that of single crystals in an ambient atmosphere. Herein, Methylammonium Lead Chloride Iodide (MAIPbCl<inf>2</inf>) is played as perovskite films, which were composited with different weight percent (wt%) of rGO from 7 to 10. All samples in this work were presented with physicochemical, electrical, and optical properties. However, the challenge of this work is the electron scattering at the grain boundaries as a result of the double schottky barrier. The best decreasing the double schottky barrier yielded a maximum conductivity of 68.72 ± 0.95 S/cm, a low sheet resistance of 5.47 ± 1.64 Ω, a decrease in the lowest oxygen vacancy, and an increase in the grain size from 27.89 nm (of MAIPbCl<inf>2</inf>) to 34.96 nm at room temperature for the MAPbCl<inf>3</inf>-8 wt% rGO composite, which also revealed that this strategy significantly helped to improve the performance of the film. Furthermore, temperature dependence for MAIPbCl<inf>2</inf>-rGO composites demonstrates this high electrical conductivity from room temperature to 323 K, with highest electrical conductivities of 78.68 ± 0.01 S/cm and the activation energy of 0.18 eV at 313 K for 8 wt% rGO. Therefore, MAIPbCl<inf>2</inf>-rGO composite films demonstrated the enhancement of performance of MAIPbCl<inf>2</inf> films; this is next promising for perovskite films in the future. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, AC/TiO2/rubber composite sheet catalysts; fabrication, characterization and photocatalytic activities(2015-11-04); Tejangkura, WorapolThe AC/TiO<inf>2</inf>/Rubber (ACTR) composite sheets weresuccessfully fabricated by a simply mixing of fixed TiO<inf>2</inf> suspension and natural rubber latex (60% HA) contents withthe varyingamounts of activated carbon (AC) suspension, followed by stirring,pouring into apetri dish mold, drying at room temperature (RT),after that taking out from a mold, reversing and drying again at RT. Then, the as-fabricated ACTR composite sheets were characterized by X-ray diffractometer (XRD), attenuated total reflectionFourier transform infrared spectroscopy (ATR-FTIR), energy dispersive X-ray spectroscopy (EDS) and scanning electron microscopy (SEM)techniques.The photocatalytic efficiencies of allACTR composite sheet sampleswere evaluated by photodegrading of methylene blue (MB) dye solution under UV light irradiation.The results showed that the photocatalytic activity of ACTR sheet with10.0wt%AC loadinghas the highest efficiency for the photodegradation of MB dye than the other sheets. This is due to the fact that it is relatively with the synergistic effect of well-combined titanium dioxide catalyst and activated carbon adsorbent. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Characterization and electrochemical properties of CuO–Cu2O@rGO nanocomposite synthesized by a seed-mediated growth process(2022-04-01); Daengsakul, SujittraA CuO–Cu<inf>2</inf>O@rGO nanocomposite (CuO–Cu<inf>2</inf>O@rGO NCP) has been successfully prepared through a seed-mediated growth process. X-ray diffraction (XRD) analysis results indicated a monoclinic phase of CuO–Cu<inf>2</inf>O@rGO NCP with space group C2/c. Transmission electron microscopy (TEM) revealed agglomeration of the CuO and Cu<inf>2</inf>O nanoparticles in the rGO sheet matrix. The interaction of CuO–Cu<inf>2</inf>O@rGO NPC resulted from the aggregation and overlapping of CuO and Cu<inf>2</inf>O nanoparticles owing to the influence of a seed-mediated growth process. The electrochemical properties of the CuO–Cu<inf>2</inf>O@rGO NPC electrode indicate the storage of energy at the surface through a pseudo-capacitive mechanism. The specific capacitance at a current density of 0.5 A g<sup>−1</sup> and the average percentage capacity retention after 1000 cycles of a CuO–Cu<inf>2</inf>O@rGO electrode at a current density of 10 A g<sup>−1</sup> were evaluated as 125.54 F g<sup>−1</sup> and 89.87 ± 3.30%, respectively. In the CuO–Cu<inf>2</inf>O@rGO electrode, the incorporated rGO affects the electrical conductivity and the synergistic interactions in charge–discharge processes. Interestingly, these results showed that the material was synthesized through a seed-mediated growth process and reveal the key factors that determine the combination and volume expansion of the reversible redox transition between Cu<sup>+</sup> and Cu<sup>2+</sup> during charge–discharge processes. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Ultrasonically-assisted surface modified TiO2/rGO/CeO2 heterojunction photocatalysts for conversion of CO2 to methanol and ethanol(2019-11-01); - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Investigation of the influences of reaction temperature and time on the chemical reduction of graphene oxide by conventional method using Vitamin C as a reducing agent(2017-01-01); ; Kongtaweelert, SamartThe aim of this work is to investigate the synthesis of reduced graphene oxide (rGO) aqueous suspension by a conventional heating method using vitamin C as a reducing agent. The influences of reaction temperatures (70, 90 and 100 °C) and heating times (30, 45 and 60 min) on the chemical reduction of graphene oxide (GO) were studied. Then, the obtained rGO samples were characterized by FT-IR, Raman, UV-Vis, XRD and TEM techniques. The FT-IR and Raman results showed that the reduction degree of GO to rGO was increased with the rising of the reaction temperature and time. Moreover, the UV-Vis spectra demonstrated that the absorption band at around 230 nm (π-π*) of pristine GO had shift to the longer wavelength upon the chemical reduction, indicating that GO is reduced to rGO. The optimal condition of the chemical reduction of GO to achievable rGO was the temperature of 90 °C with the 45 min of heating time. This condition yielded the rGO black aqueous suspension with the high quality and stability. Thus, this method of synthesis has an advantage of the rGO dispersion which led to many potential applications. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Fabrication, optical and ion conduction properties of reduced graphene oxide quantum dots and application in electrolyte supercapacitor devices(2025-05-01); Reduced graphene oxide quantum dots (rGO-QDs) were synthesized via the hydrothermal method and characterized for their structural, optical, and ion conduction properties. Raman spectroscopy confirmed a low defect density (I<inf>D</inf>/I<inf>G</inf> ratio: 0.91), while X-ray diffraction (XRD) and transmission electron microscopy (TEM) revealed reduced interlayer spacing and particle sizes (∼4.14 nm), indicative of quantum confinement effects. Optical analysis demonstrated tunable photoluminescence and strong absorption, confirming their quantum dot nature. Electrochemical impedance spectroscopy (EIS) highlighted enhanced ionic conductivity and reduced internal resistance in supercapacitor devices utilizing KOH/rGO-QDs electrolytes, improving specific capacitance and ion transport. These results establish rGO-QDs as promising materials for optoelectronics and energy storage applications, particularly in high-performance supercapacitors.