Barium Titanate Composites Research Articles

High‐Performance Textile‐Based Capacitive Strain Sensors via Enhanced Vapor Phase Polymerization of Pyrrole and Their Application to Machine Learning‐Assisted Hand Gesture Recognition

Sensors based on everyday textiles are extremely promising for wearable applications. The present work focuses on high‐performance textile‐based capacitive strain sensors. Specifically, a conductive textile is obtained via vapor‐phase polymerization of pyrrole, in which the usage of methanol co‐vapor and the addition of imidazole to the iron chloride oxidant solution are shown to maximize conductivity. A technique to provide insulation and mechanical resistance using thermoplastic polyurethane and polystyrene‐block‐polyisoprene‐block‐polystyrene/barium titanate composite is developed. Such insulated conductive elastics are then used to fabricate highly sensitive twisted yarn capacitive sensors. A textile glove is subsequently embedded with such sensors. The wireless measurement and transmission system demonstrate efficacy in capturing capacitance variations upon strain and monitoring hand motions. A machine learning model to recognize 12 gestures is implemented—100% classification accuracy is obtained.

Electromechanical Performance and Figure of Merit Optimization for Flexible Lead-Free PDMS-BaTiO 3 Piezocomposites.

In the modern era of the Internet of Things, the potential role of flexible piezoelectric generators (PEG) reflects the rapid increase in self-powered devices and wearable technologies. In this study, a casting process to elaborate the polydimethylsiloxane (PDMS)/barium titanate (BaTiO 3) composite has been presented. The addition of 15 wt % BaTiO 3 microparticles into the PDMS polymer greatly enhances the piezoelectric coefficient (d 31 = 24 pC N-1), leading to an increased output voltage of approximately 4 V under finger tapping force. The proposed flexible microgenerator yielded an excellent piezoelectric figure of merit (FoM 31 = 13.1 × 10-12 m2 N-1), significantly enhancing successfully the energy-harvesting performance (power density of 35 nW/cm2). Furthermore, the fabricated lead-free PEG exhibited an excellent flexibility figure of merit (fFoM) due to the low young modulus values (Maximum E = 3.4 MPa). These results indicate efficient energy conversion and demonstrate a favorable balance between the flexibility and piezoelectric properties of the composite, highlighting its potential for a wide range of applications in self-powered wearable sensors able to collect different human motions in applications such as gesture tracking and finger motion detection.

Photocatalytic activity of barium titanate composites with zinc oxide doped with lanthanide ions for sulfamethoxazole degradation

This comprehensive study delves into the structural and optical characteristics of barium titanate (BT) and zinc oxide (ZnO) heterostructures doped with europium (Eu), erbium (Er), and ytterbium (Yb), alongside their application in the photodegradation of sulfamethoxazole antibiotic (SMX). The heterostructures, prepared via a hydrothermal process, exhibit a heterogeneous connection between doped ZnO nanoparticles and the BT dielectric material with crystalline nature and chemical composition. Moreover, a significant reduction in the bandgap of the doped BT@ZnO:Ln heterostructures compared to undoped counterparts, indicating successful dopant incorporation and the creation of new sub-bands within the bandgap. A minimal adsorption interaction between SMX and the nanomaterials was observed. While BT alone exhibited limited photocatalytic activity, doping with ZnO significantly enhanced performance. Notably, the BT@ZnO:Yb heterostructure exhibited exceptional SMX degradation (99%) within 60 minutes. Incorporation of rare-earth ions (Eu, Er, Yb) not only improved photocatalytic activity but also acted as electron scavengers, mitigating electron-hole recombination. Furthermore, the investigation into the reuse of BT@ZnO:Yb 5%mol showed sustained high efficiency over three cycles. Mechanistic insights into SMX degradation pathways highlight the predominant role of hydroxyl radicals and electron-hole processes. Overall, these findings contribute significantly to the advancement of photocatalytic materials based on composites doped with lanthanide ions for applications in environmental wastewater treatment.

Unveiling the multi-faceted features and potential applications of novel combeite–barium titanate composites

Unveiling the multi-faceted features and potential applications of novel combeite–barium titanate composites

Multiferroic and magnetic characterization of nickel ferrite- barium titanate nanocomposites

Nickel ferrite (NiFe2O4) samples were prepared by the modified sol–gel technique which is an effective, simple, and rapid synthesis method. Multiferroic composites of nickel ferrite and barium titanate (NiFe2O4-BaTiO3) in the ratio 1:1, 1:2, 2:1 as well as composites of nickel zinc ferrite and barium titanate (Ni1-xZnxFe2O4-BaTiO3) in the ratio 2:1 were synthesized by solid-state reaction method. The formation of nickel ferrite and barium titanate heterogeneous composites was identified using X-ray diffraction analysis (XRD). Magnetic properties were studied using vibrating sample magnetometer at 300 K. The coexistence of ferroelectric and ferromagnetic order confirmed through Magneto-electric (ME) coupling measurement.

Investigation of structural, dielectric, impedance, and mechanical properties of hydroxyapatite-modified barium titanate composites for biomedical applications

Abstract This report presents the synthesis of pristine barium calcium titanate (BCT) and composite samples of [x(HA)–100 − x(BCT)]; (0 ≤ x ≤ 20) through solid-state reaction with microwave sintering. Hydroxyapatite (HA)–BCT composites have been developed to minimize grain growth, thereby boosting the material’s physical, mechanical, and electrical properties. The evaluated samples were examined for the Fourier transform-infrared spectra, and the results showed a correlation with the X-ray diffraction patterns. The real and imaginary dielectric permittivity was applied to determine the AC conductivity, and the findings indicate a drop in the frequency exponent values (S) from 1 to 0.67 for samples with x = 0. Similarly, for samples with x = 5, the value of S decreases from 0.90 to 0.55. For samples with x = 10, the value of S reduces from 0.7 to 0.54. Lastly, for samples with x = 20, the value of S decreases from 0.63 to 0.45. The exponent S and temperature relationship may be attributed to a thermal activation mechanism. The grains and grain boundary resistivity were estimated using a Cole–Cole plot, and the results showed that the grain boundary resistivity is higher in comparison to the resistivity exhibited inside the grains. This demonstrated the distinct electrical conductivity at the interfaces between the grains in comparison to the interior of the grains. The analysis of hardness indicates that the average hardness of the samples ranges from 5.22 to 4.77 GPa, which is maintained at different HA concentrations. The data suggest that this composite may have the potential to be a biomedically helpful substance.

Influence of laser intensity and BaTiO3 content on the surface properties of 3YSZ.

Zirconia-based dental implants are in direct contact with living tissues and any improvements in their bioactivity and adhesion to the tissues are highly welcome. In this study, different ratios of barium titanate (BT) were added to 3mol% yttria-stabilized zirconia (3YSZ) through conventional sintering. The laser-texturing technique was also conducted to improve the biological performance of 3YSZ ceramics. The composition and the surface of the prepared composites were characterized by X-ray diffraction and scanning electron microscopy (SEM), respectively. The roughness and surface wettability of the composites were also measured. Furthermore, MC3T3-E1 pre-osteoblast cells were used for the in vitro experiments. Cell viability was evaluated using a commercial resazurin-based method. Morphology and cellular adhesion were observed using SEM. Based on the results, the laser texturing and the barium titanate content influenced the surface characteristics of the prepared composites. The laser-textured 3YSZ/7mol% BT composites showed a lower water contact angle compared to the other samples, which indicated superior surface hydrophilicity. The cell viability and cell adhesion of 3YSZ/BT composites increased with the rise in the barium titanate content and laser power. An elongated cell morphology and apatite nucleation were also observed by the BT content. Overall, the laser-treated 3YSZ/5 and 7mol% BT composites may be promising candidates in hard tissue repair due to their good cell response.

Biological properties of polycaprolactone and barium titanate composite in biomedical applications.

The ceramic-polymer composite materials are widely known for their exceptional mechanical and biological properties. Polycaprolactone (PCL) is a biodegradable polymer material extensively used in various biomedical applications. At the same time, barium titanate (BT), a ceramic material, exhibits piezoelectric properties similar to bone, which is essential for osseointegration. Furthermore, a composite material that combines the benefits of PCL and BT results in an innovative composite material with enhanced properties for biomedical applications. Thus, this review is organised into three sections. Firstly, it aims to provide an overview of the current research on evaluating biological properties, including antibacterial activity, cytotoxicity and osseointegration, of PCL polymeric matrices in its pure form and reinforced structures with ceramics, polymers and natural extracts. The second section investigates the biological properties of BT, both in its pure form and in combination with other supporting materials. Finally, the third section provides a summary of the biological properties of the PCLBT composite material. Furthermore, the existing challenges of PCL, BT and their composites, along with future research directions, have been presented. Therefore, this review will provide a state-of-the-art understanding of the biological properties of PCL and BT composites as potential futuristic materials in biomedical applications.

Exploring the promising frontiers of barium hexaferrite and barium titanate composites for electromagnetic shielding applications

This study provides a comprehensive synthesis and meticulous examination of barium hexaferrite (BHF), barium titanate (BT), and their respective nanocomposites, unveiling their potential in specific applications, including electromagnetic interference shielding. The successful formation of BHF and BT was confirmed through Fourier-transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) analyses, revealing distinct absorption peaks indicative of the tetragonal configuration of BT and the BHF’s crystal structure. Scanning electron microscopy (SEM) depicted the unique morphologies and dispersions of particles in the synthesized nanocomposites, with BHF appearing larger (~ 82 nm) than BT (~ 50 nm). Vibrating sample magnetometry (VSM) findings exhibited an increased resistance to demagnetization with the addition of BT, despite a slight decline at 75% BT concentration due to the non-magnetic nature of BT dominating. Uniquely, the study presented an in-depth analysis of the composites’ conductivity, detailing their non-monotonic behavior across a frequency range. A detailed investigation into the complex permittivity and permeability revealed the composite’s enhanced ability to store and dissipate both electrical and magnetic energy, a function influenced by the concentrations of BT and BHF. A pivotal highlight of this research was the significant achievement of a reflection loss (RL) value of − 45 dB at 9.3 GHz for the composite with 75% BHF, suggesting the composite’s potential as an effective microwave absorber. This study represents a significant step toward designing and optimizing nanocomposites for specific applications in the realm of electromagnetic materials.

Experimental study on the radiation protecting ability of composites containing barium titanate and nanospinel ferrite

The search for new, non-toxic, and effective alternatives for radiation protection to lead-based materials is highly demanded in the present era. In the present research, a series of ceramic composites of barium titanate (BaTiO3, BTO) added with different amounts (x = 0, 5, 10, and 20 wt%) of nano spinel ferrite (Co0.8Ni0.1Mn0.1Fe1.9Ce0.1O4; NSF) were fabricated to evaluate their shielding performance against gamma radiation. The different samples were subjected to photons with energy ranging from 0.060 to 1.333 MeV emitted from Co-60, Cs-137, and Am-241-point sources, and the intensity of photons was detected using the HPGe detector. The prepared ceramics were first characterized by the XRD diffraction technique to examine the phase and crystal structure. The analysis showed the successful formation of the desired composites. The linear attenuation coefficient (LAC) values were determined experimentally to test the shielding performance of the composites. The LAC achieves its maximum values at an energy level of 0.06 MeV (31.88, 31.98, and 32.12 cm−1 for the composites with x = 5, 10, and 20 wt%, respectively, then it decreases at 0.662 MeV to 0.459, 0.461, and 0.465 cm−1 for the same mentioned compositions. LAC results showed that the current ceramics have a reasonably strong attenuation efficiency at low energy and can block many photons. The highest radiation protection efficiency (RPE) has occurred at 0.06 MeV and it is in the order of 95%. The RPE of the composite with x = 20 wt% is slightly greater than the RPE of the other ceramic samples. The half-value layer (HVL) data demonstrated that the shielding efficiency is related to the composition of the material, where the composite with x = 20 wt% showed a lower HVL than the other composites.

Microstructure and mechanical properties of BT/PVTC composite ferroelectric thin films.

Ferroelectric ceramic polymer composites have become the preferred electrocaloric materials due to their light weight and high polarization strength. But the mechanical properties were desired to be improved. In this study, the polyvinylidene fluoride trifluoro ethylene chloride (PVTC) and barium titanate (BT) composites were prepared, and the microstructure and mechanical properties were investigated by molecular dynamics simulations and experiments. It was found that with the increase of BT ceramic content in the composites, the yield stress is significantly reduced, which can be reduced by 16.07%. By comparing with the experimental data, the agglomeration and stress mechanism of the composites were proposed. The microstructure of the composite was analyzed using radial distribution function, self-diffusion coefficient, and glass transition temperature. The agglomeration mechanism of the composite was revealed from the microscopic point of view, and the rationality of the agglomeration behavior was verified by experiments. The calculations were performed by Material Studio 2019 software and the COMPASS force field was adopted.

In situ generation of H2O2 over Ce-doped BaTiO3 catalysts for enhanced piezo-photocatalytic degradation of pollutants in aqueous solution

Piezo-photocatalytic technique is a new-emerging strategy to promote the separation of electron-hole pairs and thus enhance catalytic performance. Here, a series of Ce-doped barium titanate (BTCe-x) composites were prepared by sol-gel/hydrothermal method, the applied in the removal of organic dyes in water under the piezo-photocatalytic effect. In this study, the BTCe-0.025 exhibit superior catalytic performance for different types of organic dyes (Acid Fuchsin (AF), Crystal Violet (CV), Congo Red (CR), Acid Chrome Blue K (ABK), Methylene Blue (MB), and Methyl Orange (MO)). For example, the degradation efficiency of AF, CR, and ABK is 99.1 %, 99.4 %, and 88.6 %, respectively, at a concentration of 10 mg/L for 10 min under visible light and ultrasonic vibration. This is attributed to the narrowing of the band gap and the negatively shifted conduction band under Ce doping, improving the utilization of visible light and enhancing the ability of O2 to reduce to ·O2–. Additionally, O2 in an aqueous solution generates H2O2 in situ and can react with Fe(II) to generate strongly oxidizing·OH radicals, which can greatly enhance the oxidation ability of organic pollutants. This work provides a new and efficient strategy for developing high-efficiency piezo-photocatalyst materials in removing pollutants from wastewater.

Direct-ink-writing of multistage-pore structured energy collector with ultrahigh ceramic content and toughness

Polymer-based piezoelectric composites with flexibility, lightweight and stable energy output play an indispensable role in self-powered portable electronic equipment. The addition of high-content ceramics to form three-dimensional porous structures can greatly improve the piezoelectric properties of the composites but adversely affects the flexibility and mechanical properties of the materials. In this study, multistage-pore structured polydimethylsiloxane (PDMS)/barium titanate (BT) composites with ultrahigh BT content and super toughness were manufactured through direct-ink-writing technology. The construction of multistage-pore structures with ultrahigh ceramic content greatly improved the mechanical and piezoelectric properties of the composites. The 80 wt% BT-filled composite shows a high open-circuit voltage of 45 V and short-circuit current of 2.7 μA with a stable output after 2500 voltage cycles. Furthermore, from the cyclic compression test to the strain of 30%, the ultimate stress only decreases by 12% after 2000 cycles, among which 95% occurred in the early stages (the first 100 cycles), which demonstrating stable and repeatable elasticity of ultrahigh BT-filled composite. This study provides insights for preparing high-ceramic-content piezoelectric composites through 3D printing technology for energy collection in wearable devices.

Low-frequency plasmonic state and tunable negative permittivity in percolative graphite / barium titanate composites

Percolative composites with negative permittivity have attracted widespread attentions due to their great potential in electromagnetic shielding and microwave devices. Targeting at achieving epsilon-negative properties, the percolative graphite/barium titanate (GR/BaTiO 3 ) composite is herein designed and prepared using hot-pressing sintered process. It's found that the plasma oscillations of delocalized electrons result in the epsilon negative permittivity behaviors when the GR contents exceeds the 2 wt% (percolation threshold), and frequency dependence of the negative permittivity which is in well agreement with the Drude model. Meanwhile, it's demonstrated that the ac conductivity represents a typical metal-like behavior as the conductive networks formed within the composites by the increasing GR loadings. Moreover, the equivalent circuit analysis reveals the relationships between capacitive-inductive transition and the conversion of permittivity changing from positive to negative. This work provides effective possibility for developing excellent dielectric properties of percolative GR/BaTiO 3 composite for capacitors and coil-less electrical inductors applications.

Continuous Three-Dimensional Printing of Architected Piezoelectric Sensors in Minutes.

Additive manufacturing (AM), also known as three-dimensional (3D) printing, is thriving as an effective and robust method in fabricating architected piezoelectric structures, yet most of the commonly adopted printing techniques often face the inherent speed-accuracy trade-off, limiting their speed in manufacturing sophisticated parts containing micro-/nanoscale features. Herein, stabilized, photo-curable resins comprising chemically functionalized piezoelectric nanoparticles (PiezoNPs) were formulated, from which microscale architected 3D piezoelectric structures were printed continuously via micro continuous liquid interface production (μCLIP) at speeds of up to ~60 μm s−1, which are more than 10 times faster than the previously reported stereolithography-based works. The 3D-printed functionalized barium titanate (f-BTO) composites reveal a bulk piezoelectric charge constant d33 of 27.70 pC N−1 with the 30 wt% f-BTO. Moreover, rationally designed lattice structures that manifested enhanced, tailorable piezoelectric sensing performance as well as mechanical flexibility were tested and explored in diverse flexible and wearable self-powered sensing applications, e.g., motion recognition and respiratory monitoring.

Cellulose derivative/barium titanate composites with high refractive index, conductivity and energy density

This work deals with hydroxypropyl cellulose (HPC)/barium titanate (BT) composites, having small levels of perovskite-like BT loading, i.e. 0.5–2% and being designed for electric energy storage applications. The films were obtained by solution “casting method and their structural properties were confirmed by FTIR. Scanning Electron Microscopy scans reveal that ceramic filler is well and uniformly dispersed within the cellulosic matrix. UV–VIS spectroscopy data indicate a slight increase of the absorption and the decrease of optical band gap from 5.71 eV for the HPC matrix (0% BT) to 5.20 for the sample containing 2% BT. According to refractometry analyses, the presence of BT particles determines an increase in sample polarizability, reflected in a higher refractive index, namely 1.533 and 1.605 at 486 nm for 0% BT and 2% BT samples, respectively. The values of the dispersion energy and single-oscillator energy are decreasing after filling HPC with BT, whereas first/third order optical susceptibilities and nonlinear refractive index are increasing. Mechanical tests show that incorporation of BT particles increase the value of Young modulus from 239 MPa for pure HPC to 342 MPa for 2% BT in the matrix. Dielectric studies prove that the samples exhibit a significant change in the real part of the permittivity with filler loading, ranging from 4.2 for neat HPC up to 8.5 for HPC/BT 2%.

Enhanced charge transfer in ELDC capacitors: PEDOT: PSS BaTiO3 composite separator and activated carbon electrode

The easily available coconut shell was used to make activated carbon that has a high specific capacity and good cyclability. Carbonation of the precursor was done at about 400 °C in a char reactor of limited oxygen supply followed by chemical activation at 800 °C with KOH (Carbon: Activator: 1:5) and physical activation with N2 to further enhance the property of activated carbon. Polymer PEDOT: PSS (3,4-ethylene dioxythiophene)/dielectric 0.05 wt% zirconium doped Barium titanate (BaTiO3) composite were used as separators. The electrical properties of the capacitor were measured using KEYSIGHT E4980AL precision LCR meter. The specific capacitance, energy density, and power density of capacitors were calculated from the cyclic voltammetry graph. The stacked capacitor has specific capacitance, energy density, and power density as 11.92F/g, 5.96 J/g, and 1.49 W/g.

Enhanced dielectric properties of high glass transition temperature PDCPD/BaTiO3 composites by frontal ring-opening metathesis polymerization

Polydicyclopentadiene (PDCPD)/hydroxylated barium titanate (BTOH) and PDCPD/norbornene functionalized barium titanate (BTNA) composites have been in situ prepared by frontal ring-opening metathesis polymerization (ROMP). Dynamic mechanical analysis (DMA) results show that the glass transition temperature (Tg) of PDCPD/BTNA composites was higher than that of PDCPD/BTOH, which was mainly due to the enhanced interfacial affinity between BTNA and PDCPD matrix. The PDCPD/BTNA composites exhibited high dielectric constant (20.2 at 100 Hz) due to the interfacial polarization between PDCPD and BTNA, while the non-conductive norbornene groups prevented leakage current generation and supported low loss tangent (0.017).

Magnetic and Dielectric Study of Ceramic Nanocomposite Nickel Ferrite and Barium Titanate Compounds

Owing to high dielectric constants and coupled magnetic properties at room temperature, multiferroics related materials have wide application in many fields like multi-layer ferroic capacitors and multifunctional devices. Nickel ferrite, barium titanate composite is prepared from co-precipitation method and sintered at high temperature (1273 K). Intrinsic stretching vibrations observed in FTIR spectra at 594 cm−1. X-ray measurements detected the presence of their single phases (tetragonal perovskite crystal). Variations of AC dielectric constant in these samples have been studied. The influence of the phase content on the dielectric constant and loss tangent conductivity was also studied. The AC measurement yields smaller variations at a low range of frequency and more variations in higher frequency ranges indicate amplification of confined states with the availability of large charge carriers. A magnetic measurement reveals that the soft ferromagnetic properties of 68.356 emu g−1 and 20.465 emu g−1 at room temperature.

Fabrication of PVDF/BaTiO3/CNT Piezoelectric Energy Harvesters with Bionic Balsa Wood Structures through 3D Printing and Supercritical Carbon Dioxide Foaming.

Piezoelectric energy harvesters have received widespread attention in recent decades due to their inimitable electrical energy conversion methods. However, traditional polymer/piezoceramic materials and 2D thin-film structures have limited output performance, making them difficult to be efficiently applied in the collection of discrete mechanical energy. Here, new ternary composite powders were successfully developed by the ultrasonic coating method, and array structural devices with the construction of micropores were prepared using selective laser sintering (SLS) and supercritical carbon dioxide foaming (Sc-CO2) technologies. Coating carbon nanotubes improved the polarization efficiency of poly(vinylidene fluoride)/barium titanate (PVDF/BaTiO3) composites, which made it easy to perfectly combine the BaTiO3 piezoelectric constant and the flexibility of PVDF, promoting d33 from 0.7 to 2.6 pc/N. In addition, simulations and experiments simultaneously proved that SLS parts with high array densities amplified piezoelectric outputs because of a greater compression deformation in the vertical direction. Meanwhile, under the synergistic effect of SLS and Sc-CO2, 3D bionic balsa wood structure foams were successfully fabricated, which took advantage of the normal space, expanded the stress-strain effect, and improved the piezoelectric output capability. Excitingly, the prepared foam could directly produce 19.3 V and 415 nA piezoelectric output to charge a 1 μF commercial capacitor to 5.03 V within 180 s, which surpassed most of the PVDF piezoelectric energy harvesters reported thus far. This work has an excellent innovative and practical value in enriching the types of piezoelectric materials for SLS 3D printing and the design of 3D piezoelectric structures.