BaTiO3 Nanoparticles Research Articles

Synergistic Effects of BaTiO3 and MFe2O4 (M = Mn, Ni, Cu, Zn, and Co) Nanoparticles as Artificial Pinning Centers on the Performance of YBa2Cu3Oy Superconductor

Large-scale superconductor applications necessitate a superconducting matrix with pinning sites (PSs) that immobilize vortices at elevated temperatures and magnetic fields. While previous works focused on the single addition of nanoparticles, the simultaneous inclusion of different nanoparticles into a superconducting matrix can be an effective way to achieve an improved flux pinning capacity. The purpose of this study is to explore the influence of mixed-nanoparticle pinning, with the co-addition of non-magnetic (BaTiO3; BT) and various types of magnetic spinel ferrite (MFe2O4, abbreviated as MFO, where M = Mn, Co, Cu, Zn, and Ni) nanoparticles, on the superconductivity and flux pinning performances of the high-temperature superconductor YBa2Cu3Oy (YBCO). An analysis of X-Ray diffraction (XRD) data of BT–MFe2O4-co-added YBCO samples showed the formation of an orthorhombic structure with Pmmm symmetry. According to electrical resistivity measurements, the emergence of the superconducting state below Tcoffset (zero-resistivity temperature) was proven for all samples. The highest Tcoffset value was recorded for the Y-BT-MnFO sample, while the minimum value was obtained for the Y-BT-ZnFO sample. Direct current (DC) magnetization results showed good magnetic flux pinning performance for all the co-added samples compared to the pristine sample but with some discrepancies. At 77 K, the values of the self-critical current density (self-Jcm) and maximum pinning force (Fpmax) for the Y-BT-MnFO sample were found to be eight times higher and seventeen times greater than those for the pristine sample, respectively. The results acquired suggested that mixing the BT phase with an appropriate type of spinel ferrite nanoparticles can be a practical solution to the problem of degradation of the critical current density of the YBCO material.

The energy-storage density of Polymers/BNBT6 nanocomposites with high breakdown field

Ceramic/polymer dielectric composites show significant potential for energy storage devices in advanced microelectronic applications. However, an excessive quantity of inorganic nanofillers within the polymeric matrix can lead to a substantially unequal distribution of the electric field, which may impede the improvement of energy storage density. Herein, 0.94Bi0.5Na0.5TiO3-0.06BaTiO3 (BNBT6) nanoparticles were synthesized using a combined solid-phase method followed by sieving. The silane coupling agent KH560 was used to modify the nanoparticles. Additionally, polyphenylene oxide (PPO), polytetrafluoroethylene (PTFE), and perfluoroalkyl (PFA) were utilized as matrices. The surface modification enhanced the interfacial coupling interaction between BNBT6 and the polymers, resulting in a lower concentration of interfacial hole defects. The findings demonstrated that BNBT6@KH560/PPO nanocomposites attained a high Wrec (2.71 J cm−³) and an excellent of η ∼ 81.1 % with 50 wt% BNBT6@KH560 nanofiller at 1550 kV cm−1. Furthermore, the exceptional frequency and thermal stability of BNBT6@KH560/PPO nanocomposites made it a strong contender for future portable energy devices. This work presents a feasible solution for synthesizing high-performance dielectric nanocomposites using straightforward preparation techniques.

Ferroelectric ultrafiltration membrane with improved antifouling performance

Although membrane technologies for water purification have been widely applied over decades, membrane fouling remains an inherent challenge in the membrane filtration process. Improving the hydrophilicity or surface charge of the membrane is an effective approach to mitigate membrane fouling. Here, a ferroelectric composite ultrafiltration membrane was fabricated by incorporating dopamine modified BaTiO3 nanoparticles into poly(vinylidene fluoride) (PVDF) membranes and then charged by corona poling (p-BTO/PVDF). The water permeability of p-BTO/PVDF membrane (195.0 ± 10.5 L m-2 h−1 bar−1) was increased by 2.2 times compared to the pristine PVDF membrane. The enhanced hydrophilicity and surface potential based on ferroelectric charges promoted the formation of the hydration layer on the membrane surface and increased the electrostatic repulsion against the pollutants, thus decreasing the filtration resistance and enhancing the antifouling performance of the membrane. The water recovery efficiency of the ferroelectric membrane reached 98.2 %. Furthermore, the ferroelectric membrane showed excellent antifouling stability. This work proposes an effective and environmentally friendly strategy for using ferroelectric polarization to regulate membrane anti-fouling.

The role of BaTiO3 nanoparticles as photocatalysts in the synthesis and characterization of novel fruit dyes is investigated.

In the present work, the photocatalytic activity against the natural dye extracted from the novel fruits has been studied by the BaTiO3 nanoparticles (NPs) under a ultra-violet (UV) light source. The large concentrations of an essential phenolic agent present in this phytochemical extract superimposed with cloths fibers make strong stain and degrade into another form of toxic, which is excluded from the many textiles industries as the colorful waste waters without recycling and removal of that dye pigments have been investigated using both photodegradation and photoluminescence techniques. The entitled nanoparticles (NPs) were prepared using the soft chemical root-modified solvothermal synthesis combo method and exposure to heat treatment such that the annealing process has been done for different temperatures ranging from 100°C to 250°C. As for as concern the characterization, as a start, structural and morphology studies have been reported here that highly crystalline oriented peaks data using powder x-ray diffraction techniques (PXRD) as well as the surface morphology including the size, shape, and mass distribution using the field emission scanning electron microscopy (FESEM) techniques, which purely belong to rutile tetragonal structure of the crystal system and circular and noncircular flakes like rough surface morphology materials respectively. The lattice dissociation constant 'ε' value of the BaTiO3 NPs has determined to be ~2.71 × 10-3 using the Williamson-Hall (W-H plot) analysis of crystallographic data. In the UV visible spectroscopy findings, since the extreme quantum confinement of BaTiO3 nanoflakes/nanodisc, the optical energy bandgap has been estimated to be a range of 1.98 to 2.67 eV (~2.48 eV) found from the Tauc plot analysis, which contributes to the significantly owing to the enhanced photocatalytic efficiency with excellent performance along exciton formation, superoxide ions, and hydroxyl free radicals generations under UV-vis light irradiation resulting in efficient degradation of typical novel fruit organic dye. Photoluminescence spectra observed at room temperature and low temperature have been observed for the BaTiO3 nanoflakes, which exhibit the blue emission due to the crystalline defects such as the appearance of Ba vacancies leads to the conceivable beginning of p-type conductivity and the origination of free exciton emission reveals the direct bandgap transition nature of nanoflakes. RESEARCH HIGHLIGHTS: According to our findings, 89.71% of the natural syzygium cumin is degraded by photocatalysis reaction. As a plausible mechanism for the destruction of natural dyes under solar light, photocatalytic destruction has been proposed. The reaction between these reactive free radical species leads to high efficiency photodegradation with a short decay time. In addition to water treatment and environmental cleaning applications, the excellent performance of this photocatalyst makes it a promising candidate for other applications. Hence, the synthesized BaTiO3 nanoflakes showcase a highly significant advancement towards the development of a textiles dye recycling method.

Dual zinco-phobic/-philic ferroelectric nanorods coated mesh for stable Zn anode

Aqueous Zn-ion batteries are emerging as a promising option for energy storage systems due to their safety and environmental benefits. However, their stability and reversibility are often hindered by dendrite growth and interfacial side reactions. In this study, we introduce an innovative strategy to address these issues by engineering an artificial interfacial layer (AIL) on Zn anode surface. This AIL is composed of a dual zinco-phobic/-philic ferroelectric nanorods (FE NRs) mesh, which contrasts with the traditional BaTiO3 nanoparticles. The BTO NRs, particularly those with exposed P4/mmm (100) and (211) facets enriched with oxygen vacancy, facilitate a partial phase transition from the FE tetragonal P4mm phase to the paraelectric tetragonal P4/mmm phase, thereby creating dual zinco-phobic/-philic sites. Additionally, the integration of microchannels within the FE BTO NRs mesh can efficiently modulate the electric field distribution and Zn2+ concentration, leading to a more uniform Zn deposition, as conformed by electrochemical simulations. The Zn anode coated with the FE BTO NRs mesh exhibits impressive performance, achieving an ultralong cycle life of 3050 h at 1 mA cm−2 and 1mAh cm−2. It sustains a Coulombic efficiency exceeding 99.8 % over 2000 cycles, highlighting its exceptional reversibility. These findings underscore the potential of the dual zinco-phobic/-philic FE NRs mesh in overcoming the challenges faced in aqueous metal-ion batteries, showcasing its versatility and the significant performance enhancements it can offer.

Boosting triboelectric performance of PDMS-based nanogenerators through dual-filler embedded triboelectric layers

Triboelectric nanogenerators (TENGs) provide an effective method for harvesting mechanical energy and converting it into electrical power. Polydimethylsiloxane (PDMS)-based TENGs are particularly advantageous due to their excellent mechanical properties, high flexibility, simple manufacturing process, and low cost. In this study, we suggest a PDMS-based TENG by integrating surface-modified carbon nanotubes (SMCs) prepared by pulsed laser ablation (PLA), along with high-permittivity BaTiO3 (BTO) nanoparticles. The combination of SMCs' superior electrical conductivity and BTO's high dielectric constant has synergistically enhanced the TENG's performance. Compared to pristine PDMS-based TENGs, the TENG incorporating 0.05 wt% SMCs and 7 wt% BTO demonstrated a remarkable 200 % increase in voltage (432.44 V) and a 324 % increase in current (39.23 μA). Also, plasma treatment further boosts the triboelectric performance, achieving a voltage of 468 V, a current of 43.04 μA, and a power density of 7.83 W/m².

Exploring Structural and Optical Properties of Nanoparticles of Barium Titanate and Iron doped Barium Titanate and Their Potential Application in Antibacterial Activity

Background: Barium Titanate (BaTiO3) is a good candidate for a variety of applications due to its excellent dielectric, ferroelectric and piezoelectric properties. Methods: Pure and doped Barium Titanate (BTO) nanoparticles have been synthesized by the sol-gel method. Barium hydroxide octahydrate (Ba (OH)2.8H2O) and titanium (IV) iso-propoxide (Ti {OCH[CH3]2}4) were used as starting materials. Apart from pure Barium Titanate nanoparticles, Fe-doped BaTiO3 nanoparticles of three different concentrations: 0.1, 0.2 and 0.3 in mol% were prepared and characterized using X-ray diffraction (XRD), UV visible spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR). Results: From the X-ray diffraction pattern, the particle size was found to be varied in a range of 17-25nm. By using UV visible spectroscopy it was observed that the band gap energy of pure BaTiO3 NP is 3.2eV. As the pure BaTiO3 nanoparticles are doped with 0.1% Fe, the band gap reduces to 3.175eV. For BaTiO3 doped with 0.2% and 0.3% Fe, the band gap energy values are 2.709 and 2.652 respectively. FTIR spectra were used to analyze the vibrational modes of BaTiO3. From the result obtained from FTIR, we can see that the absorption spectrum ranges from 450cm-1-4000cm-1. The prominent peak of pure BaTiO3 is at 500cm-1 which is due to the vibration of the Ti-O band in crystal lattice. For BaTiO3 doped with Fe2O3, the wave number of the absorption peak is shifted from 500cm-1 in pure BaTiO3. The antibacterial studies were conducted on Pseudomonas aeruginosa, Staphylococcus aureus and Escherichia coli. Conclusion: Both pure and iron-doped Barium Titanate showed significant antibacterial properties, confirming the antibacterial property of Barium Titanate nanoparticles.

Advancing High-Performance Piezoelectric Nanogenerators: Simple Electric Field Switching for Orientated and Aligned BaTiO3/PDMS Composite.

Barium titanate (BaTiO3) is renowned for its high dielectric constant and remarkable piezoelectric attributes, positioning it as a key element in the advancement of environmentally sustainable devices. Nevertheless, the effectiveness of piezoelectric nanogenerators (PENGs) that integrate BaTiO3 nanoparticles (NPs) and poly(dimethylsiloxane) (PDMS) poses a challenge, thereby restricting their utility in energy harvesting applications. This study presents a direct approach involving the cyclic manipulation of direct current (DC) power supply terminals to achieve unidirectional alignment of BaTiO3 NPs within a PDMS matrix, aiming to enhance the performance of the PENGs. Examination of the morphology and evaluation of diffraction planes, notably (111) and (200), in the aligned BaTiO3 PENGs exhibited well-oriented structures resulting from the repetitive switching between two electrodes, leading to improved piezoelectric properties. The BaTiO3 PENGs manifested notably higher output power (∼15 V and 1.91 μA) in contrast to devices containing randomly distributed polarized BaTiO3-PDMS composite films. The generated power was sufficient to directly operate six light-emitting diodes (LEDs) connected in series, with a collective nominal voltage of around 14 V, encompassing red, green, and blue LEDs. Nanoindentation verified the enhanced piezoelectric characteristics attributed to the alignment, sensitivity to bending, and energy-cohesive effects of clustered BaTiO3 one-dimensional (1D) pillars. These findings suggest a widely applicable technique for aligning and situating nanoparticles vertically within a polymer matrix, exploiting the intrinsic dielectric properties of the nanoparticles through a straightforward electric field switching mechanism.

Preparation of freestanding BaTiO3 nanocrystalline films and investigation of the effect of sintering on their dielectric properties

A paste was developed using commercially available BaTiO3 nanoparticles and subsequently used to fabricate 5 cm × 5 cm freestanding films via a simple screen-printing method. The dielectric properties of the resultant freestanding films were investigated using sintering temperature as a parameter. The results showed that the desired bulk behavior could not be attained in films sintered at 900 °C. When the sintering temperature was increased to 1000 °C and 1100 °C, the films exhibited bulk and single-crystal-like behaviors; sintering at 1200 °C resulted in a film with dielectric properties superior to those of bulk and single-crystalline BaTiO3. In addition, the dielectric loss was less than 0.04 in the temperature range from room temperature to 160 °C, indicating that the film is a highly practical freestanding film. The newly developed technology for forming freestanding films with thicknesses ranging from tens to hundreds of micrometers can be used to develop not only materials for multilayered ceramic capacitors but also materials for piezoelectric transducers, actuators, positive-temperature-coefficient thermistors, and ultrasonic devices.

Piezoelectric Energy Harvesting in Poly(vinylidene Fluoride‐co‐hexafluoropropylene)/Barium Titanate Nanofibers and Ultrasonic Assisted Piezocatalytic Degradation of Ciprofloxacin

AbstractAn innovative approach has been adopted through the synthesis of a cost‐effective ferroelectric host polymer, which was integrated with Barium Titanate (BaTiO3) to develop an efficient electrospun Polyvinylidene Fluoride‐Hexafluoropropylene/BaTiO3 (PVdF‐HFP/BaTiO3) nanocomposite (PBT), designated for energy harvesting and piezocatalytic applications. FT‐IR affirmed the existence of the crystalline β‐phase within the nanofibers. SEM images showed that nanofiber diameter decreases as applied voltage is increased in electrospinning. The BaTiO3 nanoparticles were scattered evenly in PBT, but at lower voltages, they aggregate. PBT showed enhanced piezoelectric performance under higher voltage conditions, registering a maximum piezoelectric output of ~7.7 V and an output current of 0.77 μA. Moreover, the composite exhibited a power density of 14.15 mW/m2 at a load resistance of 20 MΩ. Fabricated piezoelectric nanogenerator (PENG) demonstrated practical utility in flexible electronics, notably in charging capacitors of 0.47 μF and 1 μF. Additionally, the piezocatalytic degradation of the antibiotic ciprofloxacin (CIP) was effectively achieved using the electrospun nanofibers, with an impressive degradation rate of up to 99.6 % within 30 minutes under acidic conditions, and the material displayed notable reusability, maintaining up to 95.5 % efficiency after five cycles. DFT calculations and COMSOL simulations alongside a comparative examination of the electronic properties of PBT.

Flexible Thermoelectric and Piezoelectric Hybrid Energy harvester by Adopting a Multifunctional Cellulose-based Composite Film

Thermoelectric (TE) and piezoelectric (PE) energy harvesting are the most advantageous conversion mechanisms for converting energy generated by the human body into electrical energy, respectively. However, the development of a hybrid energy harvester is essential for achieving high energy conversion efficiency since a single energy harvester cannot convert enough energy. Herein, we present a flexible TE-PE hybrid energy harvester (f-TPHEH) based on a self-assembled single film consisting of Bi2Te2.7Sn0.3 particles, BaTiO3 nanoparticles, and cellulose. The fabricated f-TPHEH exhibited a maximum TE output power of 18.47 nW and a PE instantaneous output of 13.5 nW under integrated thermal and bending conditions (ΔT = 40 K, bending displacement = 7 mm). We conducted a theoretical analysis using multiphysics simulation based on finite element analysis to support the experimental measurements of the fabricated f-TPHEH. In addition, to demonstrate the mechanical stability of the cellulose matrix-based f-TPHEH, a durability test was performed up to 5,000 cycles of bending deformation. This study presents a method for developing the flexible hybrid energy harvester using a low-cost and simple fabrication process.

Dielectric constant enhancement of BaTiO3/SU-8 for low-voltage droplet actuation

Digital microfluidics (DMF) technology, which called lab-on-a-chip will bring technological innovations to the field of biochemistry. Electro-wetting-on-dielectric (EWOD) is one of the forms of DMF which actuate independent droplets through electric field enabling more accurate and efficient actuation. Nowadays, the high driving voltage required for droplet actuation remains a major obstacle to the practical application of this technology. Dielectric layer is the main factor affecting the driving voltage. In this study, we fabricate a dielectric layer film that can reduce the driving voltage by doping BaTiO3 nanoparticles with high dielectric constant in SU-8 at room temperature. The volume ratio of dopant particles and spin coating speed are studied to determine the optimal processing conditions for low-voltage droplet actuation. As the volume ratio of the dopant particles increased, the dielectric layer dielectric constant firstly increases and then decreases. When the volume ratio of BaTiO3:SU-8 is 1:10, the maximum dielectric constant is achieved. The dielectric wetting properties follow the same trend as the change in dielectric layer dielectric constant. Thus, the parameters of a volume ratio of 1:10 and spin coating speed of 7500 rad/min are finally selected for the preparation of the dielectric layer. These measures resulted in lower threshold voltages for droplet actuation, which contributes to advancing the application and widespread adoption of DMF technology.

Sol-gel hydrothermal synthesis of lead-free BT nanoparticles for enhanced dielectric properties in PVDF nanocomposites

In the present work BaTiO3 nanoparticles (NPs) with different sizes from 150 to 400 nm were prepared by sol–gel hydrothermal method at a temperature lower than 220 °C, and were used as nanofiller for PVDF composites with a loading from 10 to 25 vol%. The morphology of the BT NPs was analyzed by Scanning Electron Microscopy (SEM), and the structural composition was studied by Raman spectroscopy and X-ray diffraction (XRD). The hydrothermal temperature was found to control both the size as well as the phase composition of the BT NPs.The PVDF/BT nanocomposites exhibit enhanced dielectric permittivity and reduced loss tangent, especially with 20 vol% NPs, which contributes to the improvement of the ferroelectric properties. The inclusion of BT in PVDF matrix enhances also the crystallinity of PVDF by acting as a nucleating agent, which further increases the stiffness of the composite. However, at higher volume loading, the reverse tendency was observed with a huge decrease in the PVDF crystallinity at 25 vol%. The simulated PE loop was also investigated for the different loadings mentioned above using an Ising type model based on a 2D lattice and solved by monte-Carlo metropolis method. The results are in good agreement with the experimental results for the polarization hysteresis loops.

Ferroelectric BaTiO3 nanoparticles as peroxidase mimics for colorimetric detection of glutathione S-transferase at physiological pH

The long-standing challenges in peroxidase-mimicking nanozymes catalysis lie in their generally lower catalytic activity in comparison to natural enzymes, as well as only exhibiting specific activities within acidic environments. Herein, BaTiO3 nanoparticles (BTO NPs) operated optimally at a physiological pH and exhibited excellent peroxidase-like activity with the catalytic constant (Kcat) up to 1.99×104 s⁻1 and 9.41×103 s⁻1 for 3,3′,5,5′-tetramethylbenzidine (TMB) and H2O2 substrate, respectively, which is fourfold and twofold that of horseradish peroxidase (4.00×103 s⁻1 and 3.48×103 s⁻1). Mechanism studies suggested that BTO NPs generated internal electric fields due to spontaneous polarization, which drove free carrier separation in different directions. The free carriers led to redox reactions with H2O2 and dissolved oxygen, which produced a variety of reactive oxygen species (ROS), such as•OH, 1O2 and O2•⁻, thus effectively oxidizing the chromogenic substrates. Furthermore, due to its strong reducing property, glutathione (GSH) can inhibit the oxidation of TMB. Conversely, glutathione S-transferase (GST) reduces the inhibition of GSH by facilitating the reaction between GSH and 1-chloro-2,4-dinitrobenzene. Ultimately, a colorimetric method was established for the detection of GST at physiological pH, with a linear range of 0.025 − 5.0 U·L⁻1. This work demonstrated the great promise of screening novel peroxidase mimics with super activities from ferroelectric materials.

BaTiO3 Nanoparticles for highly efficient piezocatalytic reduction of toxic hexavalent chromium: Synthesis, optimization, and kinetic study

Drinking water contamination with heavy metals from industrial activities is an important issue. In particular, the hexavalent chromium ions Cr (VI) which are classified as group (A) carcinogens. Our research reports an effective removal of hexavalent chromium from water through the use of BaTiO3 (BTO) as a piezocatalyst. We meticulously prepared pure tetragonal BTO by optimizing the synthesis parameters. The optimized BTO catalyst was utilized for the removal of Cr(VI) under applied mechanical force and removed up to 96 % of Cr(VI) from the solution. Our kinetic study revealed that the reaction follows a pseudo-first order. Thermodynamic studies indicated that the reaction is most spontaneous at temperatures of 20 °C and concentrations of 20 ppm. Our proposed mechanism for removing Cr(VI) by BTO piezocatalysts suggests that only 15 % of chromium was removed by adsorption, while the rest was removed by reduction through the piezocatalytic process.

Manipulation of ferroelectric response of PVDF-TRFE free-standing flexible films due to incorporation of BaTiO3 nanoparticle fillers

Manipulation of ferroelectric response of PVDF-TRFE free-standing flexible films due to incorporation of BaTiO3 nanoparticle fillers

Inhibiting Shuttle Effect and Dendrite Growth in Sodium-Sulfur Batteries Enabled by Applying External Acoustic Field.

The room-temperature sodium-sulfur (RT Na-S) battery is a promising alternative to traditional lithium-ion batteries owing to its abundant material availability and high specific energy density. However, the sodium polysulfide shuttle effect and dendritic growth pose significant challenges to their practical applications. In this study, we apply diverse disciplinary backgrounds to introduce a novel method to stimulate polarized BaTiO3 (BTO) nanoparticles on the separator. This approach generates more charges due to the piezoelectric effect under stronger driving forces produced by applying a controllable acoustic field at the outer edge of the cell. The acoustically stimulated BTO attracts more polysulfides, thus reducing the shuttling effect from the cathode to the anode and ultimately enhancing the battery performance. Meanwhile, the acoustic waves create additional streaming flows, improving the uniformity of the sodium ion dispersion, enhancing the sodium ion transport and reducing the possibility of sodium dendrite development. We believe that this work offers a new strategy for the development of high-performance Na-S batteries.

Room temperature synthesis of BaTiO3 nanoparticles using titanium bis(ammonium lactato) dihydroxide

BaTiO3, known for its exceptional ferroelectric properties, is extensively applied in multi-layer ceramics capacitors (MLCCs). Achieving reliable, high-performance MLCCs requires sophisticated ceramics processes, notably in synthesizing submicron-order BaTiO3 powder with a narrow size distribution. Among various synthesis methods explored for submicron-size BaTiO3 powder, room temperature liquid-phase synthesis is most desirable due to its cost-effectiveness and large batch availability. In this study, we propose a synthesis method for obtaining BaTiO3 nanopowder at room temperature using titanium bis(ammonium lactato) dihydroxide and Ba(OH)2·8H2O as starting materials, reacted in tert-butylamine with NaOH and ethanol. The resulting powder, exhibiting a cubic phase of BaTiO3 with an average particle size of 35.8 nm, was obtained after a 7-day reaction at room temperature. Characterization involved X-ray diffraction, differential thermal analysis‒thermogravimetry, and scanning electron microscopy. Subsequently, the powder was used to sinter a BaTiO3 ceramic, whose dielectric performance was then evaluated.

Structural, optical, and morphological properties of PVC-BaTiO3 nanocomposite films

This work aims to fabricate barium titanate (BaTiO3) nanoparticles and study the effect of adding different contents of BaTiO3 nanoparticles on the structural, optical, and electrical properties of PVC polymer matrices. The PVC/BaTiO3 nanocomposite films were characterized by X-ray diffraction, FT-IR spectroscopy, and SEM. In addition, dielectric properties were studied within the frequency range of 0.1 KHz–6 MHZ. The XRD analysis reveals an amorphous nature of pure PVC with two characteristic peaks at 2θ = 17.09° and 2θ = 23.25°, and it reveals that BaTiO3 has sharp and narrow peaks. In PVC/BaTiO3 nanocomposite films, all XRD peaks of BaTiO3 appeared in all the samples with an increase in the average particle size from ∼46 nm to 55 nm. There is no shift of IR position in PVC bands, but the decreased intensity of some bands suggests complexation between PVC and BaTiO3. The UV–visible absorption spectrum of pure PVC has a band at λ = 278 nm. This band was shifted to 252 nm after adding BaTiO3 content. UV–visible transmission spectra demonstrate a decrease in the transmittance as an increase of BaTiO3 content from 89.23 % for pure PVC to 5.23 % for 0.1 wt% of BaTiO3. The values of the optical bandgap decrease with increasing BaTiO3 contents due to defect formation in PVC matrices. The optical parameters of the prepared nanocomposite films were also enhanced. The AC conductivity shows an increase with both frequency and BaTiO3 concentration, leading to enhanced movement of charge carriers and relaxation of interface polarization.

Cascade piezocatalytic nanoprodrug for synergistic piezocatalytic therapy and sono-activated chemotherapy-augmented immunotherapy

Immune checkpoint blockade (ICB) has shown great promise in the management of various cancers. However, only a small percentage of patients profit from ICB therapy. Immunogenic cell death (ICD) has demonstrated its specific capability in reconstructing the tumor microenvironment (TME) and activating anti-tumor immunity. Herein, an ICD cascade enhancement based on BPTL nanoreactors is proposed to overcome the inadequate damage-associated molecular patterns of ICD inducers. BPTL nanoreactor is formed by incorporating the piezocatalytic BaTiO3 (T-BTO) nanoparticles and paclitaxel (PTX) prodrug that responds to reactive oxygen species (ROS) into liposome nanoparticles for synergistic piezocatalytic and sono-activated chemotherapy (SACT)-augmented immunotherapy. Ultrasound (US) irradiation of the designed BPTL initiates a superior piezodynamic effect and produces ROS by piezocatalytic therapy to trigger ICD. Subsequently, the generated ROS breaks up the thioketal bonds in BPTL, thereby leading to the on-demand release of PTX for SACT and augmented ICD activation. In vivo evaluation demonstrated that BTPL with US irradiation significantly eradicated primary and distant metastatic tumors and markedly prevented the lung metastasis. This nanoplatform combines US-triggered piezocatalytic therapy and SACT for ICD stimulation, providing a robust strategy for amplifying piezocatalytic effect-mediated immune response against tumors.