PZT Particles Research Articles

Flexible Pressure Sensors Based on P(VDF-TrFE) Films Incorporated with Ag@PDA@PZT Particles.

Films of piezoelectric poly(vinylidene fluoride) (PVDF) and its copolymer P(VDF-TrFE) have been studied intensively for their potential application in piezoelectric sensing devices. The present work focuses on tuning the piezoelectric properties of P(VDF-TrFE) films via incorporating Ag and polydopamine co-decorated PZT (Ag@PDA@PZT) particles. Ag@PDA@PZT particles can effectively improve the β-phase content and piezoelectric properties of P(VDF-TrFE) films. The highest open-circuit voltage and short-circuit current of P(VDF-TrFE)-based flexible pressure sensors incorporating Ag@PDA@PZT particles are ~30 V and ~2.4 μA, respectively. The flexible sensors exhibit a response to different body movements, providing a practical and potentially useful basis for human-machine interface applications.

Settlement stability, electrical properties, and magnetoelectric properties of Mn0.5Zn0.5Fe2O4-PbZr0.5Ti0.5O3 multiferroic fluids modulating by particle sizes

Mn0.5Zn0.5Fe2O4-PbZr0.5Ti0.5O3 (MZFO-PZT) multiferroic fluids with different MZFO particle sizes were prepared, and magnetoelectric coupling effects were observed to be enhanced at room temperature. The X-ray diffraction analysis (XRD) indicates that the MZFO and PZT particles are in the pure phases. Scanning electron microscopy (SEM) images illustrate a decrease in MZFO particle size with increased ball milling time. As the MZFO particle sizes decrease, the settlement stability of multiferroic fluids becomes worse. The dielectric constant displays a nonlinear variation, exhibiting a maximum value of 4.52 at 140 Hz when the MZFO particle size is 0.55 μm. The residual polarization strength decreases and increases as particle size decreases, while the saturation polarization strength decreases gradually. The application of magnetic field results in a notable enhancement of the dielectric characteristics and ferroelectric properties, which indicates the presence of magnetodielectric and magnetoelectric coupling effects. The magnetoelectric coupling coefficient (αME) is 15.14 V/(cm·Oe) when the MZFO particle size is 0.61 μm. By modifying the strength of the applied magnetic field, the αME attains a maximum value of 114.43 V/(cm·Oe). This approach offers an effective strategy for optimizing the magnetoelectric coupling effect of multiferroic materials. Therefore, it is expected to be used in new magnetoelectric devices such as magnetoelectric random memories and magnetic field sensors.

A simple in-situ PZT oxide's decomposition: Realizing synergistic tailoring of electrical and thermal transport properties of BiCuSeO thermoelectric ceramics through band and phonon engineering

BiCuSeO, an oxide thermoelectric material with a superlattice structure, presents the advantages of affordability, low toxicity, and environmental friendliness. However, its intrinsic low electrical conductivity has impeded its possible applications. To address this challenge, we put tiny PbZr0.52Ti0.48O3 (PZT) with varying weight percentages (x = 0, 5, 7, 9, 11) into BiCuSeO (BCSO) to fabricate thermoelectric nanocomposites. Through the spark plasma sintering process, PZT particles underwent in-situ decomposition, generating nano-sized second phases such as PbO2, TiO2, and PbZrO3, which are homogenously distributed within BCSO matrix (validated by XRD and TEM). The introduced PbO2, TiO2, and PbZrO3 second phases served a dual purpose: inhibiting the grain growth of BCSO and introducing additional nano-grain boundaries. This resulted in more effective phonon scattering sites, thereby reducing lattice thermal conductivity. Simultaneously, the Pb element derived from PZT decomposition was doped into the Bi site of the BCSO matrix, causing a reduction in the band gap of BCSO from 0.49 eV to 0.388 eV and a significant increase in carrier concentration. Consequently, this doping enhanced the electrical conductivity of BCSO-based composites, with the composite with 11 wt% PZT additive amount exhibiting a remarkable 318-fold increase, reaching 550 S/cm compared to pristine BCSO. Notably, the composite with 7 wt% PZT additive amount achieved an exceptionally low lattice thermal conductivity of 0.333 W m−1 K−1 at 823 K. Through the synergistic optimization of electrical and thermal transport properties, the BCSO-based composite with 7 wt% PZT additive amount obtained a ZT value of ∼0.9 at 873 K, representing a 2.45-fold increase compared to pristine BiCuSeO. This straightforward method presents a cost-effective and scalable approach to enhance the thermoelectric performance of various materials, opening new avenues for potential commercial applications.

Self-consuming expansion stress construct piezoelectric field to accelerate anion for SiO/PbZr0.52Ti0.48O3 with persistent lithium storage performance

The high theoretical specific capacity and suitable working potential of silicon oxides (SiOx) making it one of the most promising candidates for the next generation of lithium-ion battery anode materials. However, the large-scale application of SiOx in lithium-ion battery anodes is hampered by the huge volume change (>200 %) during cycling process. This experiment adopts a method which is completely contrary to the traditional modification method——composite with piezoelectric materials to take advantage of this expansion. During the lithiation process, the significant volume expansion stress of SiO is transformed into a driving force by PbZr0.52Ti0.48O3 (PZT) particles that enhances the transport of Li+. The polarization of PZT particles occurs as a result of the consumption of mechanical stress caused by the expansion of SiO, leading to the generation of a piezoelectric potential. Since then, the volume expansion stress of SiO when deintercalating lithium is converted into a potential difference, which can promote the migration of Li+. This process not only reduces the volume expansion of SiO, but also promotes the mobility of Li+. The SiO/PZT anode shows an admirable cycle performance: The discharge capacity is 825.4 mA h g−1, and the capacity retention ratio is reach up to 92.5 % (200 mA g−1, 200 cycles). These findings illuminate the surface coupling approach employed to regulate the behavior of interfacial Li+ kinetics, while simultaneously enhancing the structural stability of alloy-based anodes. This research will undoubtedly capture the attention of researchers engaged in the study of multifunctional interface design for electrochemical systems.

Chemical modification of lead zirconate titanate piezoceramics through cold-sintering process

This study presents a facile strategy to chemically modify the PZT through the cold-sintering process. The presence of lead oxide phases in the XRD patterns of samples cold-sintered at 290 °C confirms the dissolution of Pb ions from the surface of PZT particles. Post-annealing the samples at 900 °C resulted in a phase pure material with a perovskite structure, wherein the Ba ions had diffused into the lattice of PZT. The post-annealed samples had a multi-faceted grain with equilibrated triple points and a relative density of ∼93%. The electromechanical characterization showed that the d33 of the samples increased with increasing content of Ba in the PZT, reaching a value of 201 ± 80 pm/V. The post-annealed samples displayed ferroelectric switching current behaviors with saturated polarisation loops. The experimental findings reported in this study highlight the potential of the cold-sintering process for chemical modification of lead zirconate titanate electroceramics.

Constitutive model of piezoelectric/shape memory polymer composite

The PZT/SMP composite material, combining piezoelectricity and shape memory effects, has emerged as a novel multifunctional smart material and has gained significant attention. The establishment of an effective constitutive model, describing the mechanical properties of the composites, holds tremendous importance in both theoretical and engineering realms. This study aims to develop a model to investigate the mechanical properties of PZT/SMP composites. By incorporating the deformation mechanisms of the PZT/SMP composites and the theories of viscoelasticity, the constitutive equation for PZT/SMP composites has been established. Based on composite material theory and the properties of transversely isotropic materials, combined with the material parameter equations for SMP, the material parameter equations of PZT/SMP composites have been established. Using the polarization direction of the composite material as an example, we conduct simulation analyses on PZT/SMP composites with various volume fractions of PZT particles by using the developed constitutive model. The variations in material parameter performance, piezoelectric performance, and shape memory performance are investigated. The simulation results demonstrate that an increase of PZT content in the PZT/SMP composite enhances both the piezoelectric and mechanical properties of the composite material, which significantly influences the shape memory process.

Self-sensing metallic material based on PZT particles produced by friction stir processing envisaging structural health monitoring applications

Structural Health Monitoring (SHM) of metal parts is becoming increasingly important in structural applications. However, embedding real-time sensors such as fibre Bragg gratings and piezoceramics can negatively impact the mechanical properties of the hosting metal part. To address this issue, a new Self-Sensing Material (SSM) based on lead zirconate titanate (PZT) micro-particles has been developed. Through Friction Stir Processing, PZT micro-particles were embedded in aluminium parts, and their impact on the metal parts electrical and mechanical properties was assessed. Another approach was to embed barium titanate (BT) micro-particles in metal parts. The impact of PZT particles in aluminium parts was compared to SSM based on BT particles in this study. The SSM based on PZT particles showed a higher sensitivity than the SSM based on BT particles and processed aluminium. The inclusion of PZT particles improved the mechanical strength and decreased the electrical conductivity of the aluminium parts. The SSM based on PZT particles had a sensibility of 18.0×10−4μV/MPa and could detect solicitations with different frequencies, with the best performance observed under low-frequency solicitations. Additionally, EBSD, EDS, XRD and XPS analysis confirmed the existence of the PZT particles in aluminium parts. These results are promising and guarantee an increase in sensorial properties and the ability to self-monitor metal parts.

Flexible three-dimensional interconnected PZT skeleton based piezoelectric nanogenerator for energy harvesting

Flexible piezoelectric nanogenerator (PENG) has attracted extensive attention due to the capability of energy collection and charging low-power microelectronic devices. Herein, PZT ceramic skeleton with three-dimensional (3D) interconnected network structure was fabricated via freeze casting technique. PZT/PDMS composites were prepared by introducing PDMS to the aligned pores of both green and sintered PZT skeletons. This special network structure enabled stress not to be buffered by PDMS. PENG composed of sintered PZT skeleton exhibited distinctly superior electrical output performance to that of the green one due to the effective stress transfer resulting from the direct contact between PZT particles. The maximum output voltage and output current of PENG based on 40 vol% sintered-PZT/PDMS composite reached 174 V and 28.2 μA, which were 19 V and 4.7 μA higher than those of green-PZT/PDMS composite, respectively. Thereby, this work provided a referable thought for the further development of PENG in the prospective market.

Laser Sintering of CNT/PZT Composite Film

The discovery of piezoelectricity inspired several sensing applications. For these applications, the thinness and flexibility of the device increase the range of implementations. A thin lead zirconate titanate (PZT) ceramic piezoelectric sensor is advantageous compared with bulk PZT or a polymer when it comes to having minimal impacts on dynamics and high-frequency bandwidth provided by low mass or high stiffness, while satisfying constraints regarding tight spaces. PZT devices have traditionally been thermally sintered inside a furnace and this process consumes large amounts of time and energy. To overcome such challenges, we employed laser sintering of PZT that focused the power onto selected areas of interest. Furthermore, non-equilibrium heating offers the opportunity to use low-melting-point substrates. Additionally, carbon nanotubes (CNTs) were mixed with PZT particles and laser sintered to utilize the high mechanical and thermal properties of CNTs. Laser processing was optimized for the control parameters, raw materials and deposition height. A multi-physics model of laser sintering was created to simulate the processing environment. Sintered films were obtained and electrically poled to enhance the piezoelectric property. The piezoelectric coefficient of laser-sintered PZT increased by approximately 10-fold compared with unsintered PZT. Moreover, CNT/PZT film displayed higher strength compared with PZT film without CNTs after the laser sintering while using less sintering energy. Thus, laser sintering can be effectively used to enhance the piezoelectric and mechanical properties of CNT/PZT films, which can be used in various sensing applications.

Dielectric, electric, and piezoelectric properties of three‐phase piezoelectric composite based on castor‐oil polyurethane, lead zirconate titanate particles and multiwall carbon nanotubes

AbstractThe effects of multiwall carbon nanotubes (MWCNTs) on the electrical, dielectric, and piezoelectric properties of the ferroelectric ceramic/castor‐oil polyurethane (PUR) composite films were evaluated. The three‐phase piezoelectric composites were produced by keeping PUR concentration constant while varying lead zirconate titanate (PZT) volume fractions between 10 and 50 vol.%, at two MWCNT concentrations: above and below percolation threshold. Thedcelectrical conductivity analysis revealed that small amounts of MWCNTs dispersed within PUR/PZT composite films can significantly improve electrical and piezoelectric properties due to their ability to act as conductive bridges between PZT particles in the samples. Using Jonscher's power law, it was possible to determine that the electrical conduction inacregime occurs through spatial charge hopping between states located within the piezoelectric composite. Analyzing the piezoelectric properties through thed33coefficient, it was found that PUR‐MWCNT/PZT piezoelectric composite displayed higherd33values (20 pC/N) in comparison to the PUR/PZT two‐phase composite (9.5 pC/N) for all PZT loadings. According to these results, the dispersion of MWCNT nanoparticles influences the poling effectiveness of the PZT particles and increases thed33coefficient of three‐phase piezoelectric composites.

Properties of novel 0–3 PZT/silicone resin flexible piezoelectric composites for ultrasonic guided wave sensor applications

Ultrasonic guided wave (UGW) technology based on piezoelectric sensors is considered a very promising technology for aircraft structural damage detection. Traditional piezoelectric sensors are made of lead zirconate titanate (PZT) ceramics, but their brittleness and hardness make them difficult to apply to curved structure surfaces. In this study, a novel 0–3 flexible piezoelectric composite was fabricated by dispersing PZT particles in silicone resin, and its performance for potential applications in UGW sensors was studied. The effects of polarization conditions, PZT volume fraction, and PZT powder size on the performance of the composite were investigated. The influence of ambient temperature on composite performance was discussed, and temperature adaptability experiments were conducted. The results show that the optimal poling process of 0–3 PZT/silicone resin piezoelectric composite has a poling time of 25 min, a poling electric field of 4 kV/mm, and a poling temperature of 100°C. When the sensor is required to meet the test strain range of 8,000 με, the composite should be fabricated with a PZT volume fraction of 50% and a powder size of 170∼212 μm to obtain optimal sensing sensitivity. At an ambient temperature range of -55–75°C, the fabricated piezoelectric composite sensor has good flexibility and sensitivity in detecting the guide wave signals. These research results provide a new flexible piezoelectric sensing technology for aircraft structural damage detection.

Flexible Composite Films Made of EMAA-Na+ Ionomer: Evaluation of the Influence of Piezoelectric Particles on the Thermal and Mechanical Properties.

Studies that aim to produce flexible films of composite materials based on ionomers-PZT, and volume fractions lower than 10% PZT, in order to monitor damage in aeronautical structures are seldom investigated. The growing emphasis on the use of polymers capable of self-healing after damage or activation by heating has motivated the application of self-healing ionomers as polymeric matrices in composites with piezoelectric particles aiming to monitor damage. Flexible composite films were developed based on the self-healing polymer matrix Surlyn® 8940 ionomer (DuPontTM—Wilmington, DE, USA) and PZT particles (connectivity 2–3) in volume fractions of 1, 3, 5 and 7%, with thickness around 50–100 µm. The choice of PZT volume fractions followed the preliminary requirement that establishes a final density, which is lower or at least close to the density of the materials used in aeronautical structures. Since the application of composites based on epoxy resin/carbon fibers has been increasing in the aeronautical segment, this material (with density lower than 1500 kg/m3) was chosen as a reference for the present work. Thus, due to self-healing (a characteristic of the matrix Surlyn® 8940) combined with recyclability, high flexibility and low thickness, the flexible composite films showed advantages to be applied on aeronautical structures, which present complex geometries and low-density materials. The manufactured films were characterized by SEM, XRD, DMA and mechanical tensile tests. The results were discussed mainly in terms of the volume fraction of PZT. X-ray diffraction patterns showed coexistent rhombohedral and tetragonal phases in the PZT particles-dispersed composite, which can potentialize the alignment of ferroelectric domains during polarization under strong electrical field, enhancing dielectric and piezoelectric properties toward sensing applications. DMA and tensile testing results demonstrated that the addition of PZT particles did not impair either dynamic or quasi-static mechanical performance of the flexible composite films. It was concluded that the PZT volume fraction should be lower than 3% because, for higher values, the molecular mobility of the polymer would suffer significant reductions. These findings, combined with the high flexibility and low density of the ceramic particle-filled thermoplastic polymer, render the developed flexible composite film a very promising candidate for strain and damage sensing in aeronautical structures.

Influence of carbon black and carbon nanotube on mechanical and piezoelectric properties of γ–C2S–PZT composite

This paper investigated the influence of carbon black (CB) and carbon nanotube (CNT), used at 0–1%, by volume, on mechanical performance and piezoelectricity of 0–3 γ–C2S–based piezoelectric composite. The γ–C2S–based piezoelectric composite was prepared through carbonation of the proportioned mixture. Parameters d33, g33, and εr were characterized with the CB and CNT additions. The influence of PZT size and volume on these parameters were also studied. Tested results showed that a greater PZT average size and volume significantly improved the d33, g33, and εr values of γ–C2S–based piezoelectric composite given the increased contact among PZT particles. The use of 1.0% CB can lead to 50% and 265% enhancements in d33 and εr, respectively. Such improvements in d33 and εr values were 50% and 190%, respectively, with the addition of 0.3% CNT. This is attributed to the enhanced conductivity of γ–C2S–based piezoelectric composite, which can promote the poling of PZT particles. Moreover, the compressive strength of γ–C2S–based piezoelectric composite were improved by 12 and 3 MPa with the use of CB and CNT, respectively. In addition, the γ–C2S–based piezoelectric composite had 2–6 folds greater d33 and εr values given the similar CB and CNT contents relative to those of cementitious piezoelectric composite. Therefore, the use of CB and CNT can advance the development of γ–C2S–based piezoelectric composite with enhanced mechanical performance and piezoelectricity.

Mechanical, piezoelectric, and dielectric properties of a novel 0–3 γ-C2S-PZT composite

This paper investigated the effect of PZT volume, forming pressure, and polarization regime on mechanical, piezoelectric, and dielectric properties of the 0–3 γ-C2S-PZT composite. The latter two included the piezoelectric strain coefficient (d33), piezoelectric voltage coefficient (g33), and dielectric constant (εr). Experimental results indicated that the increase of PZT volume from 0 to 80% significantly increased the d33, g33, and εr from near zero to 70 pC/N, 75 × 10−3 Vm/N, and 140, respectively, due to the enhanced contact between PZT particles. The compressive strength and d33 of γ-C2S-PZT composite were enhanced by 100% and 35%, respectively, with the forming pressure increasing from 25 to 100 MPa. Further increase in pressure to 200 MPa led to the reduction in mechanical strength and piezoelectricity due to the increased porosity of the composite. The increase of polarization voltage from 1.0 to 4.0 kV/mm resulted in doubling the d33 and g33 values. Such improvement for εr was 55%. These three parameters were enhanced by 75%, 25%, and 35%, respectively, with the increase of polarization duration from 5 to 30 min. Compared to cement-based piezoelectric composite, the γ-C2S-PZT composite had 1–5.5, 1–1.2, and 1–2.5 folds greater d33, g33, and εr values, respectively. This can enable the development of a novel low-carbon γ-C2S-PZT composite with improved piezoelectric and dielectric properties, given the reduced carbon footprint and CO2-absorbing characteristics of γ-C2S.

One-step synthesis of lead zirconate titanate particles using a solid-state reaction method

This study aims to determine the one-step synthesis of lead zirconate titanate (PbZr(1-x)TixO3; PZT) particles, using a solid-state reaction method. These particles were synthesized at x of 0.48, using a solid-state reaction (SSR) method at various operating temperatures of 700–1000 °C. Before the reaction in a muffle furnace, the precursor powder was shaker milled for 2 h. The structural analysis of the diffraction patterns showed the formation of the PZT perovskite particles. It also showed the evolution from the tetragonal phase (at 800 and 900 °C) to the coexistence of tetragonal and rhombohedral stages in samples synthesized at 1000 °C. Furthermore, the crystallite particle size synthesized and commercialized at 1000 °C were 36.00 and 47.98 nm, respectively. These showed the formation of monodispersed size distribution, with an average of approximately 4.7 μm. Therefore, the PZT particles were successfully synthesized through a one-step synthesis, using the SSR method with a pre-mixed shaker milling.

3D printed 0–3 type piezoelectric composites with high voltage sensitivity

Piezoelectric composites made of piezoelectric ceramic particles and polymer composites combine the performance advantages of both components and have broad application prospects. However, the preparation of complex structures is still a challenge, for which 3D printing technology provides a perfect solution. The aim of the present study is to investigate the principle and process optimization of the stereolithography of 0–3 type piezoelectric composites through simulation and experiments. In particular, a modified three-phase model of a spherical shell is applied to elucidate the influence of the elastic modulus between the ceramic particles and the matrix on the piezoelectric properties of the composites at the macroscopic level. This enables the piezoelectric properties of the composites to be predicted more accurately, and guides the surface grafting modification of piezoelectric ceramic powders. Furthermore, the problem of weak interface bonding in piezoelectric composites caused by poor compatibility between hydrophilic particles and the hydrophobic matrix is successfully solved by preprocessing the PZT ceramic powder via activating the particle surface hydroxyl groups and grafting a silane coupling agent onto the piezoelectric ceramic powder. As a result, the particles are bonded to the matrix by covalent bonds, which increases the elastic modulus of the interface transition layer and modifies the stress transfer efficiency. For instance, the piezoelectric strain constant (d33) of piezoelectric composite containing 60 wt% functionalized PZT particles is increased from 20 to 37 pC/N. The printing accuracy, piezoelectric properties, and mechanical characteristics of the piezoelectric composites are thoroughly investigated, and the reliability of the proposed theoretical model and simulation results is verified. The piezoelectric composites are uniformly compact and have a low residual pore rate. The piezoelectric composite with a solid content of 60 wt% has a volume density of 2.27 g/cm3 and a Young's modulus of 535.44 MPa. Most importantly, its piezoelectric voltage constant (g33) is 167.2 × 10−3 Vm/N, which is more than seven times higher than that of homogeneous PZT and results in high voltage sensitivity.

Porous, multi-layered piezoelectric composites based on highly oriented PZT/PVDF electrospinning fibers for high-performance piezoelectric nanogenerators

Piezoelectric nanogenerators (PENGs) that can harvest mechanical energy from ambient environment have broad prospects for multi-functional applications. Here, multi-layered piezoelectric composites with a porous structure based on highly oriented Pb(Zr0.52Ti0.48)O3/PVDF (PZT/PVDF) electrospinning fibers are prepared via a laminating method to construct high-performance PENGs. PZT particles as piezoelectric reinforcing phases are embedded in PVDF fibers and facilitate the formation of polar β phase in PVDF. The multi-layered, porous structure effectively promotes the overall polarization and surface bound charge density, resulting in a highly efficient electromechanical conversion. The PENG based on 10 wt% PZT/PVDF composite fibers with a 220 µm film thickness outputs an optimal voltage of 62.0 V and a power of 136.9 µW, which are 3.4 and 6.5 times those of 10 wt% PZT/PVDF casting film-based PENG, respectively. Importantly, the PENG shows a high sensitivity of 12.4 V·N−1, presenting a significant advantage in comparison to PENGs with other porous structures. In addition, the composites show excellent flexibility with a Young’s modulus of 227.2 MPa and an elongation of 262.3%. This study shows a great potential application of piezoelectric fiber composites in flexible energy harvesting devices.

Piezoelectric-driven self-accelerated anion migration for SiOX-C/PbZr0.52Ti0.48O3 with durable lithium storage performance

Silicon oxides (SiOX) based materials with great specific capacity and suitable working potential have caused widespread concern. During alloying process, the volume expansion of SiOX is approximately 200%, which limits its practical application for lithium-ion batteries (LIBs). For the purpose of surmounting the shortcomings of large volume change, a lot of efforts have been made, such as regulating the structure and morphology of active materials, incorporating with other conductive materials, and matching the suitable battery systems. However, to date, the volume expansion of SiOX anode in the cycle process cannot be absolutely avoided due to its intrinsic characteristics. In this work, these seeming drawback is creatively exploited to increase the electrochemical performance of SiOX materials. PbZr0.52Ti0.48O3 (PZT) is taken advantage as functional addition agent, which is based on piezoelectric effect elicited by volume expansion of SiOX. Specifically, the large volume change of SiOX-C could be transmitted to PZT particles, thus resulting in a polarization process. Then the piezoelectric potential is generated, so as to promote Li + mobility. SiOX-C/PZT was synthesized via a sol-gel method and high energy ball-milling procedure. Accordingly, SiOX-C/PZT anode exhibits excellent the superior cycling capability, it retains 570 mA h g-1 after 200 cycles at 400 mA g-1. Besides, it also has stable long-cycling life (430 mA h g-1 after 500 cycles at 500 mA g-1 with a retention of 75%). The relevant results demonstrate that PZT piezoelectric material can favorably increase the electrochemical property of SiOX anode materials.

Piezoelectric Property Enhancement of PZT/Poly(vinylidenefluoride-co-trifluoroethylene) Hybrid Films for Flexible Piezoelectric Energy Harvesters.

In this study, lead zirconate titanate (PZT) ceramic particles were added for further improvement. PZT belongs to the perovskite family and exhibits good piezoelectricity. Thus, it was added in this experiment to enhance the piezoelectric response of the poly(vinylidenefluoride-co-trifluoroethylene) (PVDF-TrFE) copolymer, which produced a voltage output of 1.958 V under a cyclic pressure of 290 N. In addition, to further disperse the PZT particles in the PVDF-TrFE matrix, tetradecylphosphonic acid (TDPA) was synthesized and employed to modify the PZT surface, after which the surface-modified PZT (m-PZT) particles were added to the PVDF-TrFE matrix. The TDPA on the PZT surface made it difficult for the particles to aggregate, allowing them to disperse in the polymer solution more stably. In this way, the PZT particles with piezoelectric responses could be uniformly dispersed in the PVDF-TrFE film, thereby further enhancing its overall piezoelectric response. The test results showed that upon the addition of 10 wt % m-PZT, the piezoelectric coefficient of m-PZT/PVDF-TrFE 10 wt % was 27 pC/N; and under a cyclic pressure of 290 N, the output voltage reached 3.426 V, which demonstrated a better piezoelectric response than the polymer film with the original PZT particles. Furthermore, the piezoelectric coefficient of m-PZT/PVDF-TrFE 10 wt % was 27.1 pC/N. This was exhibited by maintaining a piezoelectric coefficient of 26.8 pC/N after 2000 cycles. Overall, a flexible piezoelectric film with a high piezoelectric coefficient was prepared by following a simple fabrication process, which showed that this film possesses great commercial potential.

Piezoelectric properties and damping behavior of highly loaded PZT/polyurethane particulate composites

In this study, using a solution casting process, thermoplastic polyurethane elastomer (TPU) composites containing different contents of lead zirconate titanate (PZT) ferroelectric particles were produced. The damping treatment of composites at high volume of fillers was investigated. SEM micrographs showed that PZT particles had a proper distribution in the PU matrix. Differential scanning calorimetry (DSC) thermograms indicates that melting enthalpy decreases by raising PZT filler content. The results of the dynamic mechanical thermal analysis (DMTA) proved that the magnitude of loss factor (tan δ) strongly depends on PZT content, and it decreased from 0.51 to 0.27 as PZT content increased. The value of E0 increases to 0.32 GPa in the composite reinforced with 50 v% of PZT. The role of PZT on the acoustic behavior of TPU was measured using the acoustic absorption coefficient (a). The results showed that as PZT content increased from 0 to 50%, the acoustic absorption coefficient reached 0.25 at 6000 Hz frequency. The composites of PZT/PU with 0–3 connectivity were poled, and the optimal poling conditions that could be applied without sample breakdown were studied. Moreover, we prepared composites containing 70 vol% PZT particles by modifying the particles. Modification of PZT particles caused a decrease in both d33 and g33 constants of the PZT/PU composites.