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Synergistic Enhancement of Mechanical and Dielectric Properties in BaTiO3/PDMS Composites for Flexible Energy Harvesting Devices
(2026-01-01)
Rerngroen, Nakulkarn
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Sasipongpan, Apinya
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Vittayakorn, Wanwilai
This study presents the fabrication, characterization, and performance evaluation of flexible piezoelectric composites based on polydimethylsiloxane embedded with varying volume fractions (0–25 vol%) of barium titanate nanoparticles. The composites were prepared via a conventional casting method and systematically analyzed to investigate the synergistic enhancement of their mechanical, dielectric, and piezoelectric properties. Structural and morphological analyses confirmed the retention of the crystalline BaTiO<inf>3</inf> phase and its uniform dispersion within the PDMS matrix, with some agglomeration observed at higher filler loadings. Mechanical testing revealed that the 20 vol% BaTiO<inf>3</inf> composite exhibited optimal tensile strength and flexibility. Dielectric measurements showed significant increase in the dielectric constant with increasing BaTiO<inf>3</inf> content, with the 25 vol% composite achieving a 100% enhancement compared to pure PDMS. Theoretical modeling was employed to compare experimental results with established effective medium theories. Under cyclic compression, the composites demonstrated a progressive increase in output voltage, reaching up to ~426 V at 25 vol% BaTiO<inf>3</inf>, surpassing performance reported in previous studies. Additionally, the incorporation of carbon nanotubes further enhanced dielectric efficiency and mechanical stretchability, although a slight reduction in piezoelectric output was observed. These results underscore the potential of BaTiO<inf>3</inf>/PDMS nanocomposites, with and without CNTs, for next-generation flexible energy harvesting devices.
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Thermally induced phase transition and dielectric relaxation in lead-free BaTi0.94Sn0.06O3 Ceramics: Insights from in-situ XRD and XAS
(2025-11-01)
Sukkha, Usa
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Chanlek, Narong
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Kidkhunthod, Pinit
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Kolodiazhnyi, Taras
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Vittayakorn, Wanwilai
Lead-free BaTi<inf>0.94</inf>Sn<inf>0.06</inf>O<inf>3</inf> (BTS) ceramics were synthesized using the conventional solid-state reaction method to investigate thermally induced phase transitions and dielectric relaxation phenomena. A combination of in-situ X-ray Diffraction (XRD) and in-situ Synchrotron X-ray Absorption Spectroscopy (XAS) was employed to examine phase transitions across the temperature range of 200–400 K. The results reveal sequential phase transitions: rhombohedral-orthorhombic (R + O) at 200 K, orthorhombic (O) at 250–300 K, tetragonal (T) at 325–359 K, and tetragonal-cubic (T + C) at 373–400 K. Dielectric measurements highlight an anomalous relaxation behavior at 70–160 K, attributed to domain wall freezing. This phenomenon follows Vogel-Fulcher behavior, with an activation energy of 14 meV, a freezing temperature of 82 K, and an attempt frequency of 4.7 × 106 Hz. X-ray Photoelectron Spectroscopy (XPS) analysis reveals oxygen deficiency on the surface of the BTS ceramic, resulting in the coexistence of Ti3+/Ti4+ and Sn2+/Sn4+ oxidation states. These defects significantly influence the dielectric and phase transition properties. This study provides comprehensive insights into the interplay between local structural changes and phase transition mechanisms in BTS ceramics. By employing a multi-technique approach, it advances the understanding of dielectric and ferroelectric behaviors, positioning BTS ceramics as promising candidates for lead-free dielectric and ferroelectric device applications.
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Enhancing Performance of Composite-Based Triboelectric Nanogenerators Through Laser Surface Patterning and Graphite Coating for Sustainable Energy Solutions
(2024-11-01)
Amorntep, Narong
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Siritaratiwat, Apirat
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Srichan, Chavis
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Sriphan, Saichon
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Wiangwiset, Thalerngsak
The performance of composite-based triboelectric nanogenerators (C–TENGs) was significantly enhanced through laser surface patterning and graphite coating. The laser etching process produced accurate and consistent patterns, increasing surface area and improving charge accumulation. SEM imagery confirmed the structural differences and enhanced surface properties of the laser-etched C–TENGs. Graphite fibers further augmented the contact surface area, enhancing charge accumulation and diffusion. Experimental results demonstrated that the optimized C–TENGs, especially those with line patterns and graphite coating, achieved a maximal 98.87 V open-circuit voltage (V<inf>OC</inf>) and a 0.10 µA/cm2 short-circuit current density (J<inf>SC</inf>) under a 20 N external force. Environmental tests revealed a slight decrease in performance with increased humidity, while long-term stability tests indicated consistent performance over three weeks. Practical application tests showed the potential of C–TENGs integrated into wearable devices, generating sufficient energy for low-power applications, thereby highlighting the promise of these devices for sustainable energy solutions.
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Enhanced performance of hybrid piezo/triboelectric using BaTiO3/polymer composite film modified with rGO
(2024-01-01)
Panpho, Phakakorn
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Phetphong, Pornphiphat
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Charoonsuk, Thitirat
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Vittayakorn, Narathip
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Sriwong, Chaval
Hybrid piezo/triboelectric technology is an emerging energy source that can continuously power small electronic devices by harvesting ambient mechanical energy and converting it into electricity. In this work, a high-performance hybrid piezo/triboelectric device was presented. The composite film was synthesized that co-doped BaTiO<inf>3</inf> powders (BT) and reduced graphene oxide (rGO) embedded within a host material made of polydimethylsiloxane (PDMS). The hybrid device is made by mixing BT powders into the PDMS to form a series of composite films, ranging from 10% to 45% by wt.%. Additionally, 1–5 wt.% of rGO was loaded into fabricates 40BT/PDMS. The results show that the addition of rGO can improve the uniform dispersion of BT powder in the PDMS matrix. The 4 wt.% of rGO for 40BT/PDMS exhibited the optimal energy harvesting performance among all compositions, achieving notable output voltage and current. This work demonstrates a facile, low-cost approach for obtaining high-performance hybrid piezo/triboelectric by utilizing a composite film BaTiO<inf>3</inf> and polymer (PDMS) modified with rGO.
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Effect of ZnO and BaTiO3Nanoparticle on Partial Discharge Characteristics of Palm Oil Based Nanofluids
(2020-10-25)
Maneerot, Sakda
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Vittayakorn, Wanwilai
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Pattanadech, Norasage
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Soubol, Nichaya
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Yodrayub, Noppol
This paper presents the partial discharge inception voltage (PDIV) and partial discharge extinction voltage (PDEV) of palm oil based on nanofluids with different concentration of ZnO and BaTiO3. Each liquid specimen was prepared in a 2000 ml beaker. The palm oil sample was heated under vacuum in the oven with temperature at 80°C under 200 mbar for 12 hours. Next, these liquids were divided into seven groups according to the amount of ZnO and BaTiO3 nanoparticle. The first group was the unmodified palm oil. The second and third group were palm oil mixed with 0.01% of ZnO and BaTiO3 nanoparticle respectively. The fourth-the seventh group were palm oil mixed with 0.03% and 0.05% ZnO and BaTiO3 respectively. Then all specimens were heated at 80°C under 200 mbar for 12 hours. After that, the PDIV and PDEV of the liquid specimen were investigated using the test circuit according to IEC 60270 using needle-plane electrodes with the needle tip radius of 10 μm. Each group was tested in 6 times. The mean values of PDIV and PDEV were reported. From the test results, it was clear that the types and concentrations of nanoparticle obviously affected the PDIV and PDEV characteristics of the palm oil based nanofluids.
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High piezoelectric activity in lead-free BaTiO3-BaZrO3-CaTiO3 ceramics with near polymorphic phase boundary
(2019-01-02)
Sutapun, Manoon
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Vittayakorn, Naratip
Lead-free 0.88BaTiO<inf>3</inf>–(0.12-x)BaZrO<inf>3</inf>–xCaTiO<inf>3</inf> (BT-BZ-xCT) ceramics were fabricated via solid state reaction. The effect of CaTiO<inf>3</inf> content on crystal structure, phase transition, and electrical properties was investigated systematically. The crystal structure and phase transition of ceramics were characterized by X-ray diffraction (XRD), Raman spectra and dielectric measurement. Results show that ceramic in the composition, x = 0.02, exhibits a rhombohedral structure. Ceramics with increasing CT content transformed from a rhombohedral to orthorhombic structure in the composition, x = 0.04, and eventually became a tetragonal structure at the composition, x ≥ 0.08. The polymorphic phase boundary (PPB) was observed at the composition, x = 0.06, with coexistence of orthorhombic and tetragonal phases showing at almost room temperature. This PPB composition exhibited a high piezoelectric response (d<inf>33</inf>*) of 1,150 pm/V at 10 kV/cm as an electric field was applied. These results indicate that the materials studied have potential as candidates for lead-free piezoelectric ceramics.
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CaTiO3 induced ferroelectric phase coexistence and low temperature dielectric relaxation in BaTiO3–BaZrO3 ceramics
(2018-05-01)
Sutapun, Manoon
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Charoonsuk, Thitirat
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Kolodiazhnyi, Taras
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Vittayakorn, Naratip
The series of 0.86BaTiO<inf>3</inf>–(0.14−x)BaZrO<inf>3</inf>–xCaTiO<inf>3</inf> (abbreviated as BT–BZ–xCT) ceramics with 0.03 ≤ x ≤ 0.11 were studied to obtain high piezoelectric properties. Rietveld refinement analysis indicated that the BT–BZ–CT compositions follow a gradual rhombohedral (R) → orthorhombic (O) + R → O + tetragonal (T) → T phase transformation with increasing x. Clear evidence of the series of ferroelectric phase transitions was also found in the dielectric results. The R-O and O-T transition temperature shifted close to ambient temperature, while the Curie temperature slightly increased with increasing x. In addition to the dielectric loss peaks associated with the structural phase transitions, a broad low-temperature dielectric loss peak was detected in the R phase at T = 90-150 K. This dielectric relaxation was attributed to the domain wall freezing and fits well to the Vogel-Fulcher model with activation energy E<inf>a</inf> ≈ 60-300 meV and freezing temperature T<inf>VF</inf> ≈ 75-140 K. High piezoelectric strain coefficient (d<inf>33</inf>*) of about 1030 pm/V at 10 kV was achieved at x = 0.07, and a high Curie temperature (T<inf>C</inf>) was maintained at about 375 K.
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High piezoelectric response in the new coexistent phase boundary of 0.87BaTiO3-(0.13-x)BaZrO3-xCaTiO3
(2015-12-05)
Sutapun, Manoon
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Vittayakorn, Wanwilai
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Muanghlua, Rangson
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Vittayakorn, Naratip
An investigation of the coexistent ferroelectric phase was carried out on the ternary system of 0.87BaTiO<inf>3</inf>-(0.13-x)BaZrO<inf>3</inf>-xCaTiO<inf>3</inf> [abbreviated as BT-BZ-xCT (where 0.00≤x≤0.13)]. Temperature-, frequency-dependent dielectric data, electric field-dependent strain and polarization as a function of composition are presented in order to understand the relationships of structure-properties and find the high piezoelectric response in this system. Results showed that ceramics in the composition range of 0.00≤x<0.04 were of a rhombohedral structure and transformed into a tetragonal structure at x>0.06. The multiphase coexistence of the rhombohedral and tetragonal phase in this system was identified at x=0.06. A large, virtually hysteresis-free electric field induced strain of 0.23% was achieved with the composition, x=0.06, at 40kV/cm on the boundary between rhombohedral and tetragonal phase. This relates to an extraordinarily high and normalized piezoelectric coefficient (S<inf>max</inf>/E<inf>max</inf>) of 1280pm/V, which was reached at a low electric field applied at 10kV/mm. These results indicated that a high piezoelectric response may stem primarily from the rhombohedral-tetragonal phase boundary, due to greater lattice softening and reduced energy barriers for polarized rotation.
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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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Magnetoelectric properties of BaTiO3 - Co0.5Ni0.5Fe2o4 composites prepared by the conventional mixed oxide method
(2013-10-29)
Pulphol, Nattakarn
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Muanglua, Rangson
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Niemcharoen, Surasak
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Pecharapa, Wisanu
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Vittayakorn, Wanwilai C.
Multiferroics, which display simultaneous ferrimagnetic and ferroelectric properties, have been interesting recently because of their potentially significant applications in multifunctional devices such as magnetic resonance, drug delivery, high-density data storage, ferrofluid technology, etc. Composites combining BaTiO<inf>3</inf> with Co<inf>0.5</inf>Ni<inf>0.5</inf>Fe<inf>2</inf>O<inf>4</inf> have influenced the interest of many researchers, due to their outstanding and distinguished character called magnetoelectric (ME). In this work, ferrimagnetic-ferroelectric composites of BaTiO<inf>3</inf> nanopowder and Co<inf>0.5</inf>Ni<inf>0.5</inf>Fe<inf>2</inf>O<inf>4</inf> nanopowders were prepared by a conventional mixed oxide method. The multiferroic ceramics were compounded with the formula, (1-x)BaTiO<inf>3-</inf>(x) Co<inf>0.5</inf>Ni<inf>0.5</inf>Fe<inf>2</inf>O<inf>4</inf>, in which x = 0, 0.05, 0.10, 0.20 and 0.35. All of the compositions were analyzed by an X-ray diffractometer (XRD) in order to reveal the phase of perovskite and spinal structure. Scanning electron microscopy (SEM) was used to examine the variation of morphology and grain size of the composited ceramics. The magnetism of all the ceramics was measured using a vibrating sample magnetometer (VSM). The results showed that microstructure and the amount of ferrite are related strongly with magnetization. © (2013) Trans Tech Publications, Switzerland.

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