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The enhancement of polymer composite coating by using a waste glass powder as alternative reinforcement
(2022-01-01)
Buaphuen, Phummiphat
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Makcharoen, Worawut
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Vittayakorn, Wanwilai
Epoxy-based composites are widely used as a surface coating in the aircraft, automobile and microelectronic industries due to theirs great mechanical properties, excellent strength-to-weight ratio, lightweight, and good machinability. However, the epoxy-based coating has poor corrosion resistance in a severe environment such as in seawater. The incorporation of various fillers into epoxy resins can yield high-performance composites having high strength, lightweight, multifunctional properties and also improve corrosion resistance. Therefore, this study focuses on the preparation of inorganic nanoparticles filled in an epoxy resin matrix to create high-performance composites. The waste glass powder (WGP) was selected to use as the alternative reinforcement in epoxy resin-based composites in order to search for a sustainable and recycling filler along with the use of commercial SiO<inf>2</inf> as a comparative filler. The broken glass from household waste was processed through a high-speed vibratory milling technique until reaching the micrometer level. The physical properties, microstructure, mechanical properties, electrical properties, water absorption and corrosion resistance of all composites are investigated. The results show that after mixing WGP with an epoxy resin matrix, both Vickers hardness and abrasion resistance significantly increase compared to the neat epoxy resin whereas the water absorption ability of composites decreases. For the electrical properties, WGP does not show a significant effect on dielectric constant, dielectric loss and resistivity whereas the anticorrosive performances of the WGP/epoxy resin composite coating are improved.
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Synthesis of BaTiO3@TiO2-sheet Core-Shell Structured Nanocomposites
(2019-01-02)
Nawanil, Chanisa
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Panprom, Parinya
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Makcharoen, Worawut
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Khaosa-Ard, Krittanat
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Maluangnont, Tosapol
Core-shell structure nanocomposites have been of interest, as they can exhibit unique properties arising from the combination of peculiar characteristics of each component. In this research, core-shell structured nanocomposites, comprising barium titanate (BaTiO<inf>3</inf>; BT) nanoparticles as the core and titanate (TiO<inf>2</inf>) nanosheets as the shell, were prepared. The surface of barium titanate (BT) nanoparticles was modified chemically by hydrogen peroxide (H<inf>2</inf>O<inf>2</inf>) to create hydroxyl groups. TiO<inf>2</inf> nanosheets were deposited on the surface of the functionalized BT core, via alternate adsorption with oppositely charged polyelectrolyte poly(diallyl dimethylammonium) (PDDA) cations to produce an ultrathin TiO<inf>2</inf> shell layer that encapsulates BaTiO<inf>3</inf> nanoparticles. The structure of the core-shell particles was investigated in order to illustrate their formation mechanisms. Furthermore, this work reported the advance in utilizing a core-shell nanostructure to enhance relative permittivity and maintaining a low loss of polymer nanocomposites. A significant improvement in relative permittivity is attributed to the TiO<inf>2</inf> shell, which acts as polarizable dipoles and consequently enhances interfacial polarization. The results indicated that the structure of core-shell nanocomposites is attractive as a novel structural building block for fabricating novel materials and electronic devices.
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Electrical and dielectric properties of barium titanate–polydimethylsiloxane nanocomposite with 0-3 connectivity modified with carbon nanotube (CNT)
(2019-01-02)
Nawanil, Chanisa
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Makcharoen, Worawut
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Khaosa-Ard, Krittanat
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Maluangnont, Tosapol
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Vittayakorn, Wanwilai
This study explored the preparation and electrical properties of 0–3 barium titanate/polydimethylsiloxane nanocomposites by dispersing barium titanate nanoparticles (BaTiO<inf>3</inf>; BT) into the polydimethylsiloxane (PDMS) matrix phase. The effect of barium titanate nanoparticles on electrical properties has been investigated systematically, and the relative permittivity of nanocomposites was found to increase significantly with increasing barium titanate content. Different theoretical models were used to predict the dielectric constant of these composites and compare their experimental value with the theoretical value in order to find an appropriate equation. The result indicated that the dielectric properties of composites are influenced not only by relative permittivity of the components but also dependence on interactions between ceramics and polymers. Furthermore, the preparation and dielectric properties of BT/PDMS nanocomposites modified with carbon nanotube (CNT) were also studied. The dielectric results demonstrate that adding CNT can enhance the relative permittivity of the BT/PDMS composite via improvement of dispersion and distribution of the BT nanoparticles in the PDMS matrix phase. Moreover, the electrical outputs from the BT/PDMS/CNT nanocomposites generator were measured under periodic knocking. The nanocomposites innovatively expand the feasibility of self-powered energy systems for smart sensor and energy harvesting applications.
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Development and fatigue testing of a PZT assembly with PE housing for harvesting mechanical energy
(2019-01-01)
Punsawat, Woratat
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Khaosa-Ard, Krittanat
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Makcharoen, Worawut
This paper presents the results of simulation of design and a real fatigue test of a protected PZT assembly for energy harvesting application. The protection was from a new encapsulation design. Based on a previous unpublished research, simulation runs with ANSYS program to simulate the effect of stress on Polyethylene (PE) protective layers of various shapes were performed and the results demonstrated that PE layers of rectangular shape were able to distribute an external pressure at a suitable amount to the PZT sheet and withstand repeated pressings from an external pressure in the range of 5-20 MPa. These results enabled us to choose the best shape of PZT sheet and PE housing assembly. The fatigue parameter of the assembly was determined by subjecting the assembly to a repeated external force. And the voltage cycle of the encapsulated PZT assembly was measured with an oscilloscope. The voltage cycle test results show similarly-shaped cycles with a mean voltage of 3.76 V both before and after the assembly was subjected repeatedly to an external force. The fatigue parameter was defined as a minimum voltage that the assembly could deliver after a large number of repeated pressings by an external pressure in the range of 5-20 MPa. Our criterion of successful protection was a minimum of 3.5 V after 4,500 pressings. Therefore, we concluded that the constructed assembly was able to withstand an external operating pressure satisfactorily.
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Development of a Ternary Composite of PU Resin/Carbon Black/PZT for Mechanical Energy Harvesting Application
(2018-01-01)
Punsawat, Woratat
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Makcharoen, Worawut
Today, rapid depletion of energy sources forces us to discover alternative sustainable electrical energy sources quickly. The aim of this work was to develop a ternary composite of PU resin/carbon black/PZT to be an efficient mechanical energy harvester. Specifically, this present work attempted to find the optimum weight ratio of a PU resin/carbon black/PZT composite that could provide the highest mechanical-to-electrical conversion efficiency. The PU resin was the main matrix. Carbon black (CB) was added to improve conductivity while still maintaining good casting property. Then, PZT was added to generate electricity. Testing several weight ratios of this composite, it was found that the samples ratio of 60:20:20 was optimum and able to generate an average voltage of 0.357 V/in2. This ternary composite material has a candidate to into a practical and efficient electrical energy harvester source.
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Dielectric Relaxation and Microstructures of SnO2 Doped CaCu3Ti4O12 Electroceramics Prepared Via Vibro-milling Method
(2017-01-01)
Makcharoen, Worawut
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Punsawat, Woratat
High dielectric constant CaCu<inf>3</inf>Ti<inf>4</inf>O<inf>12</inf> (CCTO) is a compound with a high dielectric constant, but it has a high loss tangent at room temperature. This research aims to study on the dielectric properties and loss tangent of SnO<inf>2</inf> doped CaCu<inf>3</inf>Ti<inf>4</inf>O<inf>12</inf> (CCTO) ceramics were investigated. The ceramic samples of SnO<inf>2</inf> doping CCTO were prepared by a solid-state reaction method. The characterization of the samples was carried out using scanning electron microscopy (SEM) and x-ray diffraction (XRD). The conventional solid-state reaction was employed. The metal oxide powders were mixed using a vibratory milling for 6 hour and sintered at 1000°C for 4 hour. The phase formation of the calcined powders and sintered ceramics was examined by X-ray diffraction technique (XRD). Microstructure was examined by scanning electron microscopy (SEM). SnO<inf>2</inf> doping produced a notable decrease in grain size. Average values of grain size, as measured by the linear intercept method. The dielectric measurements at room temperature to 130°C, in the frequency range 100 Hz- 500 kHz. The XRD result a CCTO structure does not changes on Sn doped samples. The results show the loss tangent at room temperature and at 100 kHz decreased from 0.14 for the 0 mol% Sn doped CCTO sample to 0.04 for the 2.0 mol% Sn doped sample while at 500 kHz, it was decreased from 0.2 for the undoped CCTO sample to 0.04 for the 2.0 mol% Sn doped sample. However, the lowest loss tangent was 0.02 at 500 kHz and at 65°C and show a stable loss tangent in temperature range 25 - 130°C.
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Effect of platinum substitution on the microstructures and dielectric relaxation of CaCu3Ti4O12 ceramics
(2013-10-29)
Makcharoen, Worawut
The CaCu<inf>3</inf>Ti<inf>4</inf>O<inf>12</inf> (CCTO) has the advantage for the various applications especially for capacitive elements in microelectronic devices over the ferroelectric materials including BaTiO<inf>3</inf>. CCTO is a ceramic compound with a high dielectric constant but it has a high loss tangent at room temperature. In this work, the Influences of PtO<inf>2</inf> doping on the dielectric properties of CaCu<inf>3</inf>Ti<inf>4</inf>O<inf>12</inf> (CCTO) ceramics were investigate. The ceramics CCTO and PtO<inf>2</inf> doping CCTO were studied by Xray diffraction, scanning electron microscopy. The dielectric properties have been measured as a function of temperature and frequency range 0.1 - 500 kHz. The XRD shows the CCTO structure does not changes after doping with platinum. The results show that PtO<inf>2</inf> doped can reduce the mean grain sizes of CCTO, but the dielectric constant still remained a height. The samples of 2.0 mol% Pt-doped have exhibited high dielectric constant of about 22,000 and the loss tangent about 0.7 at room temperature and frequency at 10 kHz. The reduced of the loss tangent could be interpreted with the internal barrier layer capacitor model (IBLC) © (2013) Trans Tech Publications, Switzerland.
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Microstructures and dielectric relaxation behaviors of pure and tellurium doped CaCu3Ti4O12 ceramics prepared via vibro-milling method
(2013-05-01)
Makcharoen, Worawut
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Tunkasiri, Tawee
In this work, we have reported microstructures and the dielectric properties of CaCu<inf>3</inf>Ti<inf>4</inf>O<inf>12</inf> (CCTO) ceramics doped with different proportions of TeO<inf>2</inf> dopant (mol%, x=0, 0.5%, 1.0%, 2.0%). The pure and tellurium doping CCTO ceramics were prepared by a conventional solid-state reaction method and the effects of TeO<inf>2</inf> doping on the electrical properties and microstructures of these ceramics were investigated. XRD analysis confirmed the formation of single-phase material in samples. Scanning electron microscopy (SEM) is used in the micro structural studies of the specimens, which showed that TeO<inf>2</inf> doping can reduce the mean grain size and increasing size of an abnormal grain growth. Lattice parameter increases slightly with tellurium doping in CCTO, the dielectric constant reached a value as high as 18,000 (at 1 kHz) at a tellurium-doping concentration of 2.0 mol% and showed temperature stability at high frequency. The loss tangent of Te-doped CCTO ceramics was less than 0.05 at 1 kHz region below 105 °C. The loss tangent properties could be interpreted by the internal barrier layer capacitor model and the impedance measurement data. © 2012 Elsevier Ltd and Techna Group S.r.l.
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Effect of different preparing methods on the microstructures and dielectric relaxation behaviors of CaCu3Ti4O12 ceramics
(2013-01-01)
Makcharoen, Worawut
In this work, we report the dielectric properties and microstructure of the CaCu<inf>3</inf>Ti<inf>4</inf>O<inf>12</inf> (CCTO) ceramics, it were prepared with different techniques. The ball-milling and vibro-milling techniques were used in this study. The dielectric constant (ε<inf>r</inf>) of CCTO ceramic samples, which were prepared by the vibro-milling and sintered at 1100°C for 4h have had a higher dielectric constant of CCTO ceramics which were prepared by the ball-milling technique. These vibro-milled CCTO ceramics also possess excellent dielectric constant even at the higher frequency (10-100 kHz) while their dielectric loss is having still under 0.1 at temperatures not over 100°C. This vibro-milled CCTO ceramics offer a promising candidate for resistance random access memory applications, especially in the frequency range of 10-100 kHz. © 2013 Copyright Taylor and Francis Group, LLC.

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