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Synergistic Integration of MgAl-LDH Nanosheets into Bacterial Cellulose for High-Performance Triboelectric Nanogenerators
(2025-08-04)
Mohsom, Phitchayaphorn
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Suktep, Natdanai
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Sae-Tang, Chanachot
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Pongampai, Satana
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Pakawanit, Phakkhananan
A novel nanocomposite design is presented in which magnesium aluminum layered double hydroxide (MgAl-LDH) nanosheets are synergistically integrated with bacterial cellulose (BC) to fabricate a flexible triboelectric nanogenerator (TENG). Utilizing a facile solution synthesis combined with a casting process, composite films with controlled MgAl-LDH loadings (0.25–5% v/v) were developed. The optimal composite, containing 1.5% v/v MgAl-LDH, exhibits an open-circuit voltage (V<inf>OC</inf>) of 88.5 V, a short-circuit current (I<inf>SC</inf>) of 87.7 μA, and a maximum output power (P<inf>max</inf>) of 1250 μW (power density ≈138 μW/cm<sup>2</sup>), which is > 35 times higher than that of pristine BC. Notably, this performance corresponds to a superior filler efficiency metric, demonstrating a highly effective use of the nanosheet additive compared to other reported systems. This performance enhancement is attributed to the multifunctional role of MgAl-LDH nanosheets in increasing the dielectric constant through improved interfacial conductivity and the formation of parallel microcapacitors under an induced electric field. Finite element simulations corroborate the proposed mechanism, and practical demonstrations show the nanocomposite powering 200 LEDs as well as functioning as a self-powered sensor for finger movement monitoring. These findings advance the development of high-performance, flexible energy-harvesting devices.
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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)
Boonyarattanakalin, Kanokthip
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Rattan, Praphaporn
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Songpanit, Maneerat
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Chutipaijit, Sutee
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Okumura, Hideyuki
In 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.
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Structural and Optical Characterizations of Polymethyl Methacrylate Films with the Incorporation of Ultrafine SiO2/TiO2 Composites Utilized as Self-Cleaning Surfaces
(2023-08-01)
Songpanit, Maneerat
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Boonyarattanakalin, Kanokthip
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Limwichean, Saksorn
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Lertvanithphol, Tossaporn
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Horprathum, Mati
The structural and optical characterizations of nanocomposite films of polymethyl methacrylate (PMMA) and SiO<inf>2</inf>/TiO<inf>2</inf> composites prepared via the spin-coating technique were investigated using different SiO<inf>2</inf>:TiO<inf>2</inf> ratios. The SiO<inf>2</inf>/TiO<inf>2</inf> nanocomposites were synthesized using the sonochemical process with Si:Ti precursor ratios of 1:0.1, 1:0.5, 1:1, 1:2, 1:4, and 0:1. All characterizations of ultrafine SiO<inf>2</inf>/TiO<inf>2</inf> particles were loaded at 1 wt.% in a PMMA matrix for the fabrication of transparent SiO<inf>2</inf>/TiO<inf>2</inf>/PMMA composite films. The phase structure and morphology of SiO<inf>2</inf>/TiO<inf>2</inf>/PMMA composite films were monitored using X-ray diffraction, optical microscopy, and field-emission scanning electron microscopy. A surface roughness analysis of SiO<inf>2</inf>/TiO<inf>2</inf>/PMMA nanocomposite films was conducted using atomic force microscopy. For optical characterization, transmission properties with different incident angles of SiO<inf>2</inf>/TiO<inf>2</inf>/PMMA composite films were analyzed with UV-vis spectrophotometry. The water contact angles of SiO<inf>2</inf>/TiO<inf>2</inf>/PMMA composite films were analyzed to identify hydrophilic properties on film surfaces. Photocatalytic reactions in SiO<inf>2</inf>TiO<inf>2</inf> composite films under UV irradiation were evaluated using rhodamine B dye degradation. The optimal condition of SiO<inf>2</inf>/TiO<inf>2</inf>/PMMA nanocomposite films was obtained at a 1:1 SiO<inf>2</inf>:TiO<inf>2</inf> ratio in self-cleaning applications, resulting from good particle dispersion and the presence of the TiO<inf>2</inf> phase in the composite.
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BaTiO3/Epoxy Resin Nanocomposites as Flexible Energy Storage Devices
(2023-01-01)
Vittayakorn, Wanwilai
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Tepsansern, Piyapat
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Kriangkraikul, Worachet
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Vittayakorn, Naratip
In this work, nanocomposites between the epoxy resin and barium titanate (BT) were prepared in order to use as flexible energy storage devices. The epoxy resin and BT phase were homogeneously mixed and cast into a disk shape. Phase formation and chemical properties of these nanocomposites were identified via XRD and FTIR methods, respectively. Frequency dependence of dielectric properties for all samples was measured by LCR meter. The polarization hysteresis loops were also investigated in order to calculate the energy density of materials. From the results, it was found that the dielectric constant and loss of these nanocomposites are independent of frequency and the ε<inf>r</inf> and tanδ values tend to increase with increasing BT amount. Moreover, after adding 50% of BT into the system, the energy density of nanocomposites is increased by five times compared with the pure epoxy resin while the energy loss density sharply decreases. The dielectric properties and the energy density of BT/epoxy resin nanocomposites change with BT content and strongly depend on porosity and the distribution of BT nanoparticles.
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Cu- and Sn-Codoped Mesoporous BaTiO3-G-SiO2Nanocomposite for Bioreceptor-Free, Sensitive, and Quick Electrochemical Sensing of Rhizopus stolonifer Fungus
(2022-04-26)
Fatema, Kamrun Nahar
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Areerob, Yonrapach
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Meng, Ze Da
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Zhu, Lei
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Oh, Won Chun
Rhizopus stolonifer produces large postharvest losses that account for about 80% of total losses in prepackaged and loose tomato fruits from Rhizopus rot. In this study, we effectively synthesized a Cu- and Sn-codoped mesoporous BaTiO3-G-SiO2 (CuSnBTGS) nanocomposite by utilizing a simple, low-cost self-assembly method for the electrochemical detection of Rhizopus stolonifer fungus; this method does not require a biological or chemical receptor or antibodies. We focused on the microstructure design of CuSnBTGS in combination with Cu and Sn codoping, which is widely regarded as the most efficient way to produce high-performance electrodes. The resultant CuSnBTGS composite exhibited excellent electrochemical characteristics and remarkable performance in the direct detection of Rhizopus stolonifer (bread fungus) levels in contaminated solutions. The chronoamperometric response of the CuSnBTGS composite electrode was linear with Rhizopus stolonifer fungus concentrations in the 50-100 μL range, with a lower detection limit of 0.50 μL. The sensor electrode demonstrated high sensitivity, repeatability, and selectivity. The findings show that Cu- and Sn-codoped mesoporous BTGS is a viable alternative to costly electrode materials, such as gold and platinum, for amperometric sensor applications, demonstrating its applicability in the agricultural and food safety sectors.
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Modification of dye-sensitized solar cell working electrode using TiO 2 nanoparticle/N-doped TiO2 nanofiber composites
(2014-01-01)
Mekprasart, Wanichaya
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Suphankij, Sineenart
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Tangcharoen, Thanit
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Simpraditpan, Athapon
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Pecharapa, Wisanu
Nanocomposite films of N-doped TiO<inf>2</inf> nanofibers (NFs) and commercial-grade TiO<inf>2</inf> nanoparticles Degussa (P25) were utilized as working electrode of typical dye-sensitized solar cells (DSSCs). N-doped TiO<inf>2</inf> NFs were fabricated via electrospinning method using ammonium acetate (CH<inf>3</inf>COONH<inf>4</inf>) as nitrogen source and titanium (IV) isopropoxide (TiP) in ethanol as starting precursor in combination with calcinations process. The electrospun NFs were characterized by XRD, Raman spectroscopy, XPS, SEM, and TEM. The photoelectric conversion performance of the DSSCs with composite film electrode was compared to the device using pure P25 film. The result shows that as calcination temperature increases, the anatase-to-rutile phase transformation and the fiber size reduction of NFs were observed. The energy conversion efficiency (η) of the device tends to increase with increasing calcined temperature with specific nanofiber loading content, indicating the significant enhancement in the device performance by the incorporation of the NFs. This enhancement of DSSCs may attribute to high surface area, higher light scattering and light harvesting, low charge recombination, and fast electron-transfer rate by loaded NFs. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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Fabrication and properties of BaTiO3-CoFe2O 4 nanocomposites
(2013-12-01)
Vittayakorn, Wanwilai C.
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Pulphol, Nattakarn
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Muanghlua, Rangson
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Vittayakorn, Naratip
In this work, BaTiO<inf>3</inf>-xCoFe<inf>2</inf>O<inf>4</inf>, where x = 0, 0.1, 0.2, 0.3, 0.4 and 0.5, nanocomposites were prepared by conventional mixing method and followed by normal sintering in air. The effect of processing condition on phase formation, microstructure, magnetic and electrical properties of the BaTiO<inf>3</inf>-CoFe<inf>2</inf>O<inf>4</inf> nanocomposites was investigated. The phase development and microstructural evolution of this system have been determined via X-ray diffractometer and scanning electron microscope. From the results, it concludes that phase formation, microstructure, electrical and magnetic properties of the BaTiO<inf>3</inf>-xCoFe<inf>2</inf>O<inf>4</inf> nanocomposites strongly depend on chemical composition. © 2013 Copyright Taylor and Francis Group, LLC.
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Characterization and dielectric properties of nanocomposite made of lead zirconate nanofibers and polyvinylidene fluoride improved with carbon nanotubes
(2013-12-01)
Nawanil, Chanisa
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Rerkratn, Apinai
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Seeharaj, Panpailin
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Vittayakorn, Naratip
A three-phase PZ/CNT/PVDF nanocomposite comprising lead zirconate (PZ) nanofibers, polyvinylidene fluoride (PVDF) and a small volume fraction of carbon nanotubes (CNT) was prepared by the solvent casting technique followed by composite heating at 80°C. The PZ/CNT/PVDF composites were characterized by X-ray diffraction, FT-IR and scanning electron microscopy (SEM). The dielectric properties of the composite were studied as a function of the frequency by an LCR meter. The dielectric constant of the PZ/CNT/PVDF nanocomposite was found to be in the range of 18-61 within the measurement frequencies from 100 Hz to 2 MHz. This value is higher than the dielectric constant of the PZ/PVDF nanocomposite. The measured dielectric properties demonstrate that the addition of CNT can improve the dielectric property appearance of the composite. © 2013 Copyright Taylor and Francis Group, LLC.
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Hydrothermal synthesis of nanofibers from natural ilmenite mineral and their utilization for dye-sensitized solar cell
(2013-12-01)
Simpraditpan, Athapon
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Wirunmongkol, Thanakorn
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Pavasupree, Sorapong
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Pecharapa, Wisanu
Titanate nanofibers were synthesized by a hydrothermal method using a low-cost ilmenite mineral as the starting material. The crystalline structure of the as-synthesized nanofibers demonstrated titanate structure (H <inf>2</inf>Ti<inf>x</inf>O2x+<inf>1</inf>). The bi-crystalline mixture consisting of TiO2 (B) and anatase TiO<inf>2</inf> nanofibers was obtained by heat treatment at 500°C for 2 h. Dye-sensitized solar cells (DSSCs) with photoanode consisting of the nanocomposite of nanoparticles and nanofibers (5%) rendered a light-to-electricity conversion efficiency (η) of 0.28%. In contrast, the cells with photoanodes consisting of only nanoparticles and nanofibers exhibited η of 0.25% and 0.15%, respectively. © 2013 Copyright Taylor and Francis Group, LLC.

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