Poly Vinylidene Fluoride Composites Research Articles

Tailoring the Thermal Diffusivity of Polyvinylidene Fluoride via Carbon Source Integration: A Photothermal Beam Deflection Study

The work reported in the paper addresses the thermal diffusivity (TD) tuning of the electronic sensor material polyvinylidene fluoride (PVDF). The thermal properties of electronic material were found to influence the device characteristics significantly, demanding novel techniques for TD tuning. The TD value of the carbon sources—hydroxyethyl cellulose (HC), lignin (LG), and camphor soot (CS) and their composites—were measured by the sensitive nondestructive evaluation technique—photothermal beam deflection. When the HC and LG enhanced the TD of PVDF by 237.5% and 27.5%, respectively, CS was found to lower it by 11.25%. The spectroscopic analysis revealed the variation of hydroxyl groups in the samples and suggested its prominence in deciding the TD value. The Fourier transform infrared analysis and beam deflection measurements exhibited a positive correlation between hydroxyl groups and TD, except for the composite PVDF combined with soot. In this case, the amorphous carbon in soot reduced PVDF’s TD due to the heat trap mechanism of carbon allotropes. The induced variation of TD of PVDF via carbon source integration is attributed to the closure of pores in PVDF, revealed through the optical microscopic images, thereby suggesting a methodology for enhancing or reducing TD of PVDF.

Flexible thermoelectric energy harvesting system based on polymer composites

Flexible and easy processing lightweight thermoelectric materials for energy harvesting applications have shown an increasing interest. Thermoplastic polyvinylidene fluoride (PVDF) and elastomer styrene-ethylene/butylene-styrene (SEBS) polymers reinforced with thermoelectric ceramics, including bismuth sulfide (Bi2S3), bismuth telluride (Bi2Te3) and antimony telluride (Sb2Te3), and electrically conductive carbon nanotubes (CNT) have been developed, tailoring their thermal and electrical properties for thermoelectric device applications. The Seebeck coefficient of the composites increases with thermoelectric ceramic filler content for semicrystalline PVDF composites, slightly decreasing for amorphous SEBS composite. Thermoelectric power factor and figure-of-merit in the polymer composites increases up to 9 orders of magnitude with respect to the pristine polymer, up to a maximum value of 10−3 µW/(m·K2) and 10−6, respectively, for the PVDF/CNT/Bi2Te3 composite. A device composed by 2 printable p-n thermocouples based on PVDF/50Bi2S3 and PVDF/50Bi2Te3 can generate power in the order of the nW and charge a capacitor with 5 V. Theoretical modeling allows to evaluate different thermoelectric configurations, the effect of the number of thermocouples and the influence of the temperature gradient on device performance.

Microstructure control in printable porous polymer composites

The microstructure of a porous polymer matrix composite, specifically the organization of polymer, particles, and pores, plays a defining role in the physical properties of the material. Developing materials and processes that allow us to control the microstructure gives us a powerful tool to create materials with designed performance. Here, a series of porous polyvinylidene fluoride (PVDF) and alumina (Al2O3) composites produced through evaporation induced phase separation (EIPS) are demonstrated. This process utilizes solution processable inks and achieves porosity via a simple drying procedure. This enabled the materials to be printed using direct ink writing (DIW) techniques. The effects of particle size and loading on the mechanical properties and microstructures of these materials were studied. It was found that these materials remain significantly more ductile and extensible than what is expected from particle reinforcement. In the most extreme case, the use of 300 nm Al2O3 particles were found to only minimally reduce strain at failure, even at high loadings. We believe this behavior is enabled by how the EIPS process alters the microstructure of the material and appears to preferentially locate particles at the polymer-pore interface.

Fractal texture and dielectric properties of BaTiO3/poly-vinylidene fluoride composites

The effects of the dispersion state of BaTiO3 ceramic fillers, which significantly improve the dielectric constant of BaTiO3/polyvinylidene fluoride composites, were investigated. To understand the microscopic and macroscopic features of the obtained composite textures, we have attempted a multifractal analysis of the microstructure of composite materials. The fractal nature of the composite material texture was investigated using multifractal parameters (the qth-moment dimension D(q) and scaling exponent τq) in the formation of fractal aggregates of BaTiO3 (BT) particles in polyvinylidene fluoride (PVDF) composites. In the plots of D(q) and τ(q) vs q, the obtained results confirmed that q > 0 could be quantitatively evaluated as local characteristics (morphology, arrangement, and dispersion), whereas q < 0 could be quantitatively evaluated as global characteristics (aggregate network structure formation). As a result of evaluating the internal energies and entropies of the micro- and macro-regions from the plot of τq vs q, the aggregate formation energy (E1), aggregate network formation energy (E2), and interaction energy between the aggregates (Eint) had a relationship of E2 = E1 + Eint. The configuration entropy for the aggregate network formation (S2), particle arrangement entropy (S1), and aggregate configuration entropy (Sint) had a relationship of S2 = S1 + Sint. At q > 0, the increase in the aggregate formation energy with the amount of additive indicates the formation of particle groups. At q < 0, the generation of the interaction energy between the aggregates (Eint) suggests that the particle groups interact to form an aggregate network. Similarly, at q > 0, the increase in the arrangement entropy with the amount of additive is related to the arrangement of particles, while at q < 0, the generation of the configuration entropy (Sint) is related to the formation of the particle group network. It was clarified from the multifractal analysis that the formation of particle groups and their network structure are strongly related to the piezoelectric characteristics in this BT/PVDF system. It was revealed that the Eint and Sint obtained from the plots of D(q) and τ(q) vs q of the multifractal analysis could be related to the formation of particle groups (local interaction) and occurrence of network structure (global interaction). Therefore, the plots of D(q) and τ(q) vs q are effective means of characterizing self-organization from the fractal nature and are expected to be applied in more general research fields other than material and condensed matter.

Interfacial insight of core@double‐shell Mo@MoO3@PS/PVDF composites towards prominently meliorative dielectric performances

AbstractPolymer dielectrics with synergistically large dielectric permittivity (ε') and breakdown strength (Eb) but prohibited loss is of crucial applications in the electronic devices and power equipment. In this study, we aim to elevate the integrated dielectric performances of molybdenum (Mo)/polyvinylidene fluoride (PVDF) by constructing a semiconducting molybdenum oxide (MoO3) shell and insulating polystyrene (PS) shell on the Mo surface through high‐temperature oxidation followed by suspension polymerization. The resulting core@double‐shell Mo@MoO3@PS particles were compounded with PVDF to achieve high ε' and Eb while minimizing the loss. The results reveal that the Mo@MoO3@PS/PVDF composites indicate simultaneously ameliorative ε' and Eb along with restrained loss owing to the existence of the MoO3@PS double‐shell, which not only prominently enhances the interfacial compatibility and interactions between fillers and PVDF, but significantly inhibits the conductivity and loss through impeding the long‐distance motion of carrier charges. The dielectric capabilities could be improved by adjusting the thickness of the PS interlayer. The Havriliak‐Negami equation was used to fit the experimental results, which showed the impact of the PS shell on the polarization mechanism and how it inhibits carrier migration. The Mo@MoO3@PS/PVDF with high ε' and Eb yet exceptionally low loss exhibit potential applications in microelectronics and electrical industries.

Enhanced piezoelectric performance of ZnSnO3@PVDF composite films by control of embedded contents of ZnSnO3 nanoparticles

We report on ZnSnO3 (ZTO) nanoparticles embedded polyvinylidene fluoride (PVDF) composite (ZTO@PVDF) film-based piezoelectric nanogenerators (PENGs). To fabricate the PENG devices, the ZTO nanocubes (NCs) with an average side length of 910 nm were synthesized by the ethanol precipitation method and they were mixed with PVDF with different embedded contents ranging from 0 to 40 wt%. The PENG with 30 wt% ZTO@PVDF showed the highest output performance with an open circuit voltage of 160 V, short circuit current of 2.04 μA and power density of 36.27 μW/cm2 under 0.27 MPa mechanical force. The accelerated crystallization of β phase in PVDF by the strong Coulombic forces of ZTO nanoparticles with PVDF chains significantly improved the energy harvesting values compared to previously reported perovskite-PVDF PENGs. The enhanced piezoelectric performances by ZTO NCs in PVDF was confirmed by COMSOL simulation and it showed that the maximum piezoelectric performance of PENGs was achieved with the 30 wt% ZTO nanoparticles embedded in the PVDF composites. In terms of applications, we demonstrated with the lighting of 120 LEDs and operation of a temperature timer with ZTO@PVDF PENGs. Our suggested flexible PENGs with ZTO NCs mediated β phase nucleation technology of PVDF will be adopted to a promising mechanical energy harvesting and self-powered wearable sources and wireless device application.

Combined effect of hybrid carbon fillers on the physical and rheological properties of polyvinylidene fluoride composites

Combined effect of hybrid carbon fillers on the physical and rheological properties of polyvinylidene fluoride composites

Electrospinning composites of polyvinylidene fluoride - carbon black on solid phase microextraction fibers for enhanced detection of volatile organic compounds by gas chromatography-mass spectrometry

Urine contains volatile organic compounds (VOCs) that can be a source of biomarkers for different medical conditions. Headspace solid phase microextraction (HS-SPME) gas chromatography-mass spectrometry (GC–MS) is the gold standard for VOC detection but is time-consuming and expensive. Gas sensors on the other hand are portable and provide rapid results, but qualification of sensing layers is tedious as VOCs need to be tested individually. Our previous study showed that dip coating SPME fibers, using them to extract VOCs from urine and analyzing them by GC–MS is a tool to rapidly characterize sensing elements. The current study aims to extend these findings to demonstrate that HS-SPME GC–MS can identify how electrospinning can enhance the detection of VOCs due to the increased surface area. Herein, previously optimized suspensions of polyvinylidene fluoride-carbon black (PVDF-CB) were deposited on SPME fiber substrates through dip coating and electrospinning, used to extract VOCs from urine and were subject to GC–MS. Electrospinning parameters (applied voltage, flow rate and duration) were optimized, which showed that an applied voltage of 17 kV and a flow rate of 0.25 mL/hr was optimal for electrospinning fibers with 1.5 µm diameter, high coverage and little to no beading. SPME fibers electrospun with PVDF-CB for 10 min were compared to dip coated fibers, and the results showed electrospun fibers had increased efficiency to extract an abundant number of VOCs in urine. These VOCs were enriched when sampled by the electrospun fiber by factors ranging from 1.5 – 5.5. Results also showed that the electrospun fibers had significantly higher reproducibility (p-value < 0.001) relative to dip coated fibers. In summary, electrospinning has the capability of fabricating more sensitive SPME fibers relative to dip coating, and therefore may be utilized in the future for an array of different applications including but not limited to VOC biomarker discovery.

Preparation of a hollow fiber membrane made of antifouling PVDF/Zeolit using the dip-coating technique

The practical technique for membrane modification is dip coating. This study coats a PVDF hollow fiber membrane-based composite with a coating of zeolite. The composite is made of a polyvinylidene fluoride (PVDF) membrane. During water filtering, the separation capabilities and propensities of composite membranes for organic impurities were examined. SEM and Fourier-transform infrared spectroscopy analysis of the findings demonstrated that the Zeolite coating was successfully deposited on the PVDF membrane. The flux recovery ratio increases from 69% to 80% while the relative flux drop decreases from 63% to 50%. A composite PVDF membrane dip-coating of Fe2O3/Zeolite with a GA and H2SO4 ratio of 1:2 is needed to remove about 75% of humic compounds from effluent. The results of this study show that the addition of Fe2O3/Zeolite with a GA and H2SO4 layer can greatly improve the hydrophilicity, selectivity, and anti-organic fouling of the PVDF hollow fiber membrane.

The sustainable recycling of polyvinylidene fluoride membrane for tribological application

AbstractIn the study, the waste polyvinylidene fluoride (PVDF) membranes were recovered and the obtained resin powders by a solvent recovery method were employed for the fabrication of a novel PVDF‐based tribological composite. Herein, a new strategy was developed for applying the waste PVDF membranes to fabricate a self‐lubricant composite, where the recycled PVDF powders acted as the polymer matrix and microcapsules with the configuration of polysulfone (PSF) capsuling lubricant oil (PAO) served as the filler. The morphologies, crystal phases, chemical components and groups as well as thermal stabilities of fabricated PAO@PSF/PVDF composites were characterized, and the self‐lubricating and wear properties of fabricated composites were tested under the dry sliding condition using a ball‐on‐disc configuration. Experimental results suggest that the PAO@PSF/PVDF composite with an addition of 20 wt% PAO@PSF microcapsules exhibits the best tribological properties, in view of the lowest friction coefficient (0.077) and the smallest wear rate (2.34 × 10−15 m3/Nm). The incorporation of PAO@PSF microcapsules greatly reduces the friction coefficient of PVDF polymer. The tribological properties of fabricated PAO@PSF/PVDF composite will be expectable to that of the PVDF polymer with the dripping presence of lubricating oil.

Fabrication of CuO-NP-Doped PVDF Composites Based Electrospun Triboelectric Nanogenerators for Wearable and Biomedical Applications.

A flexible and portable triboelectric nanogenerator (TENG) based on electrospun polyvinylidene fluoride (PVDF) doped with copper oxide (CuO) nanoparticles (NPs, 2, 4, 6, 8, and 10 wt.-% w.r.t. PVDF content) was fabricated. The structural and crystalline properties of the as-prepared PVDF-CuO composite membranes were characterized using SEM, FTIR, and XRD. To fabricate the TENG device, the PVDF-CuO was considered a tribo-negative film and the polyurethane (PU) a counter-positive film. The output voltage of the TENG was analyzed using a custom-made dynamic pressure setup, under a constant load of 1.0 kgf and 1.0 Hz frequency. The neat PVDF/PU showed only 1.7 V, which further increased up to 7.5 V when increasing the CuO contents from 2 to 8 wt.-%. A decrease in output voltage to 3.9 V was observed for 10 wt.-% CuO. Based on the above results, further measurements were carried out using the optimal sample (8 wt.-% CuO). Its output voltage performance was evaluated as a function of varying load (1 to 3 kgf) and frequency (0.1 to 1.0 Hz) conditions. Finally, the optimized device was demonstrated in real-time wearable sensor applications, such as human motion and health-monitoring applications (respiration and heart rate).

Designing of the green γ-AlOOH@Naringin thin film composite PVDF based nanofiltration membrane and application for pharmaceutical wastewater treatment

Herein, the green naringin functionalized boehmite (γ-AlOOH@Nar) bionanocomposite was used to fabricate the high-performance thin film composite (TFC) polyvinylidene fluoride (PVDF) based nanofiltration (NF) membrane with enhanced antifouling properties and pharmaceutical rejection. For this aim, the PVDF NF membrane was first activated by triazinyl groups. Then the membrane surface was subsequently functionalized by the γ-AlOOH@Nar nanocomposite at different concentrations (0.2, 0.4, and 0.6 wt%). The γ-AlOOH@Nar TFC NF membranes were characterized by means of Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), atomic force microscope (AFM), zeta potential, and thermogravimetric analysis (TGA). Moreover, the mean pore radius, porosity, surface hydrophilicity, salt rejection, pure water flux, and antifouling properties of the membranes were investigated. The 0.4 wt% γ-AlOOH@Nar TFC (TFC-0.4) membrane showed a pure water flux of 53.6 L/m2h and FRR of 95.4%, which were about 2.3 and 2.4 times that of the blank membrane. The TFC-0.4 membrane not only provided the highest permeability and surface hydrophilicity but also lowered the irreversible fouling ratio while keeping high pharmaceuticals rejection (99.8% for both Ceftriaxone (CTX) and cephalexin (CEX)). The pharmaceutical wastewater filtration showed that the γ-AlOOH@Nar TFC membranes achieved high normalized flux and also provided 89.8% COD removal, 100% turbidity removal, and moderate TDS removal (53.0%). Overall, the γ-AlOOH@Nar TFC membranes exhibited high separation performance and excellent antifouling properties showing their great potential for use in pharmacutical wastewater treatment facilities.

On PVDF composite as partially absorbable smart implants.

For various orthopedic needs, several studies have been testified on non-absorbable implants, prepared with different metals/alloys, and composites. But yet little has been stated on the partially absorbable smart implants of thermoplastic composites for online health monitoring of veterinary patients. This article highlights the in-house development of affordable, polyvinylidene fluoride (PVDF) composite-based partially absorbable smart implants (with online sensing capability) for orthopedic needs in canines. Hydroxyapatite (HAp) and chitosan (CS) nanoparticles were reinforced in the PVDF matrix by a melt processing route with various weight proportions (wt.%) to fabricate a partially absorbable smart implant for the canine. The study suggests that the 8.0 wt.% HAp and 2.0 wt.% CS in PVDF is the superlative composition/proportion of reinforcement for preparing feedstock stock filaments (for 3D printing of partially absorbable smart implants), based on rheological, mechanical, thermal, dielectric, and voltage-current-resistance (V-I-R) characteristics. For the selected composition/proportion of PVDF composite, acceptable mechanical properties (such as modulus of toughness (MoT) 2.0 MPa, Young's modulus (E) 889 MPa), and dielectric properties (dielectric constant (εr) 9.6 at room temperature (30°C) and 20 MHz) for online sensing capabilities (for health monitoring) was observed. The results are braced by attenuated total reflection Fourier transform infrared (ATR-FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) analysis.

Synthesis of functionalized ZnO nanoflake loaded polyvinylidene fluoride composites with enhanced energy storage properties

AbstractPolymer composite films are ideal materials for advanced energy storage capacitor in electrical systems. Therefore herein, we fabricated a novel series of polyvinylidene fluoride (PVDF) based composites embedded with well dispersed ZnO@APTES {surface modified zinc oxide with (3‐Aminopropyl) triethoxysilane (APTES)} nanoflake (0, 20, 30, 40, 50) vol% through solution casting method. Hydrothermally synthesized two‐dimensional ZnO was pre‐treated with H2O2 and surface modified with APTES for perfect distribution of nanoflake into PVDF matrix. Surface modification and high aspect ratio morphology of ZnO@APTES enhanced the interfacial interaction between organic PVDF and inorganic ZnO through reduction in heterogeneity between them. Surface functionalization reduced the dielectric loss and improved the overall energy storage performance. Investigation of electrical properties proclaimed incorporating 30 Vol% ZnO@APTES in PVDF as optimized loading due to its appreciable Wrec (recoverable energy density) about 3.2 J/cm3. Relative comparison of the energy storage density (Wrec) of PVDF/ZnO@APTES (30) vol% with recent published works established its enhanced capacitive response and its future application in energy storing portable device.

Additively Manufactured Micro‐ and Nano‐ Al/PVDF Ignition Sensitivity and Burning Characterization

AbstractAluminum (Al) and polyvinylidene fluoride (PVDF) composites can be used in many unique applications in the field of energetic materials. Due to their low melting point, many PVDF composites can be additively manufactured. However, more research is needed to better understand the ignition and combustion of these materials. Manipulating the size of aluminum (Al) particles in Al/PVDF composites can drastically alter the burning rate, ignition characteristics, and possibly flame temperatures. This study characterizes the ignition of additively manufactured micro‐ and nano‐ Al/PVDF composites through hotwire ignition tests. Both nAl and μAl particles were mixed in PVDF at 20 wt.% and additively manufactured into disks via fused filament fabrication. The nAl/PVDF printed disks ignited at a minimum ignition power (MIP) of 4.1 W compared to the 9.5 W required for ignition of μAl/PVDF disks. At identical powers, ignition delays were significantly shorter for nAl/PVDF disks. Additionally, while the nAl/PVDF disks reacted instantaneously at any power above their MIP, the μAl/PVDF disks exhibited smaller, localized flames before complete combustion, if the power was below 17.5 W. Flame temperatures were estimated through three‐color pyrometry and compared to thermochemical equilibrium calculations. While theoretical flame temperatures for nAl/PVDF and μAl/PVDF are 2023 K and 2314 K respectively, both samples burned near 2000 K when measured using pyrometry.

Enhanced piezoelectric response in BTO NWs-PVDF composite through tuning of polar phase content

We have fabricated a flexible, environment friendly piezoelectric nanogenerator (PENG) based on the ferroelectric Polyvinylidene fluoride (PVDF) composite incorporated with Barium titanate (BaTiO3) nanowires (NWs) of piezoelectric coefficient d 33 = 308 pm V−1. The single-layered PENG can deliver output power density of 10 μW cm−2 and an output voltage of 2 V with a nominal mechanical load of 1 kPa. BaTiO3 (BTO) NWs of different concentrations were incorporated into PVDF to tune the polar phase content, internal resistance, and optimize the output power. We show that there exists a critical value of BTO NWs loading of 15 wt%, beyond which the piezoelectric energy harvesting characteristics of the PVDF nanocomposites decrease. The oxygen vacancies present in the BTO NWs surface attract the fluorine ions of PVDF chain and favour the formation of β phase. The enhanced value of dielectric constant and dielectric loss of BTO-PVDF samples in the low frequency region suggest strong interfacial polarization in the composite system. The fabricated PENG can charge a super-capacitor up to 4 V within 35 s. The origin of the high power output from the BTO (15 wt%)-PVDF composite is attributed to the combined effect of enhanced polar phase content, strong interfacial polarization, and reduced internal resistance. This study provides an effective pathway in enhancing the performance of BTO-PVDF based piezoelectric energy harvesters.

Enhancing Thermal Conductivity of Polyvinylidene Fluoride Composites by Carbon Fiber: Length Effect of the Filler.

Thermally conductive polyvinylidene fluoride (PVDF) composites were prepared by incorporating carbon fibers (CFs) with different lengths (286.6 ± 7.1 and 150.0 ± 2.3 µm) via cold pressing, followed by sintering. The length effects of the CF on the thermal conductivity, polymer crystallization behaviors, and mechanical properties of the PVDF composites were studied. The through-plane thermal conductivity of the PVDF composites increased significantly with the rise in CF loadings. The highest thermal conductivity of 2.89 W/(m∙K) was achieved for the PVDF composites containing 40 wt.% shorter CFs, ~17 times higher than that of the pure PVDF (~0.17 W/(m∙K)). The shorter CFs had more pronounced thermal conductive enhancement effects than the original longer CFs at higher filler loadings. CFs increased the storage modulus and the glass transition temperature of the PVDF. This work provides a new way to develop thermally conductive, mechanically, and chemically stable polymer composites by introducing CFs with different lengths.

Nano-Sized Calcium Copper Titanate for the Fabrication of High Dielectric Constant Functional Ceramic-Polymer Composites.

A novel calcium copper titanate (CaCu3Ti4O12)–polyvinylidene fluoride composite (CCTO@PVDF) with Cu-deficiency was successfully prepared through the molten salt-assisted method. The morphology and structure of polymer composites uniformly incorporated with CCTO nanocrystals were characterized. At the same volume fraction, the CCTOs with Cu-deficiency displayed higher dielectric constants than those without post-treatment. A relatively high dielectric constant of 939 was obtained at 64% vol% CCTO@PVDF content, 78 times that of pure PVDF. The high dielectric constants of these composites were attributed to the homogeneous dispersion and interfacial polarization of the CCTO into the PVDF matrix. These composites also have prospective applications in high-frequency regions (106 Hz). The enhancement of the dielectric constant was predicted in several theoretical models, among which the EMT and Yamada models agreed well with the experimental results, indicating the excellent distribution in the polymer matrix.

3D printed innovative customized solution for regulating weathering effect on heritage structures

• 3D printed solution with acceptable corrosion resistance towards chemical weathering faced by heritage structures. • Effect of acid rain on 3D printed customized innovative strips of PVDF composite. • Innovative PVDF composite based smart strips for crack repair. In the recent past, some studies have been reported on applications of 3D printing processes as an innovative and cost-effective solution for the maintenance and repair of heritage structures. But hitherto little has been reported on ascertaining the weathering effect (acid rain) on such heritage structures revamped as 3D printed customized solutions. This study highlights the effect of H 2 CO 3 on 3D printed customized innovative strips with alternate layers of conducting (polyvinylidene fluoride (PVDF)-6%graphene-3%Mn-doped-ZnO) and non-conducting (PVDF-6%CaCO 3 ) composites engineered for controlled self-expansion and contraction (SEC). Based on the acceptable SEC features of the innovative 3D printed strip (as 4D characteristics), the composite structure was tested for corrosion resistance to mimic the acid rain environment. The results obtained for composite structure based on the Tafel exploration outlined that the proposed 3D printed solution possesses acceptable corrosion resistance (2.84 × 10 -7 mm/y) towards chemical weathering faced by heritage structures.

Novel high dielectric polymer composites with BaTiO3 co-doped by Nb2O5 and Co3O4

BaTiO3 (BT) and BaTiO3 modified with Nb2O5 and Co3O4 (BT@NC) were used as fillers and polyvinylidene fluoride (PVDF) as matrix to prepare BT/PVDF composites and BT@NC/PVDF composites, respectively. Microstructure, phase composition, dielectric properties and breakdown strength were investigated. 50 vol% BT@NC/PVDF composite exhibits high dielectric constant of 70.2 (at 104 Hz) and low dielectric loss of 0.02. It also possesses energy storage density of 0.7 J/cm3 at 47.2 kV/mm, which is 123.2 % higher than that of 50 vol% BT/PVDF composite. Therefore, modification of BT can be a good approach to increase dielectric response and enhance energy storage of BT@NC/PVDF composites.