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In this work, we designed a novel polyvinylidene fluoride (PVDF)@DNA solid polymer electrolyte, wherein DNA, as a plasticizer-like additive, reduced the crystallinity of the solid polymer electrolyte and improved its ionic conductivity. At the same time, due to its Lewis acid effect, DNA promotes the dissociation of lithium salts when interacting with lithium salt anions and can also fix the anions, creating more free lithium ions in the electrolyte and thus improving its ionic conductivity. However, owing to hydrogen bonding between DNA and PVDF, excess DNA occupies the lone pairs of electrons of the fluorine atoms on the PVDF molecular chains, affecting the conduction of lithium ions and the conductivity of the solid electrolyte. Hence, in this study, we investigated the effects of adding different DNA amounts to solid polymer electrolytes. The results show that 1% DNA addition resulted in the best improvement in the electrochemical performance of the electrolyte, demonstrating a high ionic conductivity of 3.74 × 10−5 S/cm (25 °C). The initial capacity reached 120 mAh/g; moreover, after 500 cycles, the all-solid-state batteries exhibited a capacity retention of approximately 71%, showing an outstanding cycling performance. [ABSTRACT FROM AUTHOR]

The notch effect of semicrystalline PVDF was investigated using U- and V-notch geometries with different depths, and tensile tests were performed at 23 °C using the DIC technique and FEA. Both unnotched and notched dumbbell-shaped specimens were subjected to tensile loading with the DIC technique to obtain mechanical curves and strain maps. The experimental data were compared to a numerical model, analyzing both global mechanical curves and local strain maps around the notch region to assess the accuracy of the simulations. The results demonstrated that the geometry and depth of the notch influence the mechanical behavior of PVDF, presenting a decrease in load and displacement compared to unnotched specimens. This aspect was corroborated by strain maps, which showed the increase in the local strain around the notch tip. For FEA, the global analysis indicated a good correlation with experimental results, and the local analysis demonstrated a reasonable agreement in strain map results within 0.5 mm of the notch neighborhood. Overall, the DIC technique and FEA provided a reliable evaluation of notch behavior on the PVDF used as pressure sheaths with reasonable precision. [ABSTRACT FROM AUTHOR]

The crystal structure has a great influence on the dielectric and piezoelectric performance of poly(vinylidene fluoride) (PVDF). In this work, we prepared PVDF films with two typical crystalline phases (α and β). In situ Kelvin probe force microscopy (KPFM) and Piezoelectric force microscopy (PFM) were employed to investigate the responses of different PVDF crystalline phases to charge mobility, polarization, and piezoelectric properties. We used a homemade Kelvin probe force microscope (KPFM) to inject charges into the two crystalline phases to investigate the differences in the response of different crystalline phases of PVDF to electrical excitation on a microscopic scale. It was found that the α-phase has a lower charge injection barrier and is more susceptible to charge injection and that the α-phase is accompanied by a faster charge dissipation rate, which makes it easier to accumulate charge at the interface between the α-phase and β-phase PVDF. Moreover, the PFM polarization manipulation showed no change in the amplitude and phase diagram of the α-phase under ±10 V bias. In contrast, the β-phase showed a clear polarization reversal phenomenon and a significant increase in piezoelectric amplitude, which is consistent with its polar intrinsic properties. This study provides valuable insights into the multiphase contributions and a reference for designing advanced PVDF dielectrics. [ABSTRACT FROM AUTHOR]

The rising widespread oil‐impacted wastewater warrants an urgent call for innovative approaches to the handling of oily wastewater. A variety of techniques has been investigated to treat oil‐impacted water, and they are found to be inefficient. Electrospun nanofibers emerge as the viable technique to treat oily wastewater precisely owing to their high specific surface areas and interconnected nanoscale pore structures. In this review, a brief background on the study is provided followed by the environmental pollution by the oily wastewater. Subsequent to that, the polyvinylidene fluoride (PVDF) modification methods are also presented followed by the physicochemical properties of both the electrospun PVDF blends and the PVDF‐based composites. Furthermore, the performances of the PVDF‐based composites in oil/water separation are described. It is concluded with the future prospects for using PVDF‐based composites for oil/water separation. [ABSTRACT FROM AUTHOR]

Given global water scarcity and the quest for sustainable energy, there's a pressing need for integrated approaches addressing water‐energy interdependence worldwide. A practical approach for this challenge involves the implementation of fog water collectors. Herein, a polyvinylidene fluoride (PVDF) multifunctional device capable of harvesting water and electricity from wind is developed and tested, collecting up to 365 mg cm−2 h−1 of fog water. Due to the piezoelectric nature of electrospun PVDF, these yarns and meshes not only serve as piezoelectric sensors, enabling the detection of incoming fog flow and determination of its speed and, bust also harvest electricity by charging a capacitor, making it a green and renewable power source. In this study, promising insights are offered into developing efficient fog water collection methods and utilizing piezoelectric fiber‐based yarns and meshes for multifunctional applications in sustainable water management, energy harvesting, and sensing in a single device. [ABSTRACT FROM AUTHOR]

In this work, a strain sensor was fabricated using conductive electrospun polyvinylidene fluoride (PVDF) nanofiber film coated with carbon nanotubes (CNTs) on a polyimide (PI) substrate. An investigation of the sensor's properties during stretching and relaxation under varying experimental conditions was undertaken. The morphologies of the sensing films were examined to gain an understanding of their structure. The experimental design was complemented by simulation to optimize the shape and size of the substrate to ensure uniform and consistent straining under loading conditions. The insight derived from the computational analysis played an instrumental role in selecting the appropriate substrate design and determining the ideal location for placing the PVDF/CNTs sensing film. The difference in the deformation value of the substrate with the selected design during the computational and experimental analysis was 17.5%. An integrated approach, combining both experimental and computational methodologies, was used to significantly enhance the study's value and facilitate the development of an efficient and effective strain sensor. The sensor displayed a gauge factor (GF) of 1.83 and 1.19 under the incremental loads of 0.98 and 1.96 N, respectively. In conclusion, this study contributes to an improved understanding of the strain sensor's characteristics and potential applications in structural health monitoring technologies. [ABSTRACT FROM AUTHOR]

Recently, conductive polymer‐based composites (CPC) have gained considerable interest for their outstanding processing, mechanical, electrical properties, and resistance tunability. Multi‐walled carbon nanotube (MWCNT) was introduced into polyvinylidene fluoride (PVDF) as the conductive filler via means of melt blending in this work. Effects of MWCNT on crystalline structure, thermodynamic behavior, electrical conductivity, processing and mechanical properties of PVDF/MWCNT were under investigation. By measuring the volume resistivity of PVDF/MWCNT, it was observed to have declined from 1.54 × 1012 to 3.71 × 101 Ω∙m with the MWCNT content changed from 0.7 to 1 vol%, which plummeted by 11 orders of magnitude. Therefore, it can be inferred that the percolation threshold of MWCNT lies within the range of 0.7–1 vol%. Additionally, the percolation threshold is obtained as 0.81 vol% by fitting using the percolation theory equation. Around the percolation threshold, PVDF/MWCNT composites exhibit negligible alterations in their rheological properties when contrasted with pure PVDF, yet their mechanical properties are improved. Furthermore, MWCNT does not substantially impact the crystalline structure and thermodynamic behavior of PVDF/MWCNT. Highlights: The percolation threshold of MWCNT in PVDF is 0.81 vol%.The volume resistivity of the 1 vol% MWCNT sample was only 3.71 Ω∙m.1 vol% MWCNT exhibit favorable rheological and mechanical properties. [ABSTRACT FROM AUTHOR]

The quest for efficient and sustainable methods to mitigate carbon dioxide (CO2) emissions is a pressing global challenge. This study delves into the crucial role of polymers in tailoring the performance of titanium dioxide (TiO2) nanofibers for CO2 conversion reactions. By systematically comparing the influence of different polymers, specifically polyvinyl pyrrolidone (PVP) and polyvinylidene fluoride (PVDF), on the CO2 conversion activity of TiO2-NFs, we shed light on the remarkable potential of polymeric selection to fine-tune catalyst properties. The paper uses advanced experimental techniques to analyze the structural and morphological properties of PVP-TiO2-NFs and PVDF- TiO2-NFs demonstrating their various morphologies. The investigation involves SEM, XRD, BET, Raman, and UV-Vis spectroscopy to better understand the charge separation and recombination processes involved in both materials' CO2 conversion. The results show considerable differences, the choice of polymer significantly impacts the CO2 conversion performance of TiO2-NFs. PVP-based NFs exhibit enhanced surface area and porosity, resulting in superior catalytic activity, while PVDF-based NFs demonstrate remarkable stability. These findings pave the way for innovative approaches to tackle climate change and develop a more environmentally friendly future by advancing energy-efficient and long-lasting photocatalytic technology. [ABSTRACT FROM AUTHOR]

This study focuses on the synthesis of a PVDF membrane using DMAc as the solvent through a combination of evaporation-induced phase separation (EIPS) and non solvent-induced phase separation (NIPS) techniques. The experimental findings underscore the significant role of thermodynamic and kinetic parameters in the phase inversion process, influencing the surface and transport properties of the resulting membrane. By precisely controlling the combined processes of EIPS and NIPS, a customized membrane with specific characteristics such as a rough surface (roughness of up to 725.9 µm) and hydrophobicity (water contact angle up to 117°) was successfully achieved. The synthesized membrane exhibits good membrane properties (total porosity ≥ 50%, mean pore size ranging from 0.01 to 0.35 μm) with well-connected pores. To assess its quality, the membranes permeate flux, reaching up to 12.8 kgh−1 m−2, and salt rejection rate of 99.8% were evaluated using Vacuum Membrane Distillation (VMD). Furthermore, a fouling study was conducted to investigate the impact of operating time on membrane performance, revealing a negligible decline in membrane fouling over a 200-h run. [ABSTRACT FROM AUTHOR]

Separators play a crucial role in enhancing the electrochemical performance of lithium-ion batteries (LIBs). However, achieving separators with exceptional electrochemical performance and high stability remains a significant challenge. In this study, we meticulously designed composite membranes based on polyvinylidene fluoride (PVDF) with varying contents of microcrystalline cellulose/tetraethyl orthosilicate (MCC/TEOS). The increase in hydrophilicity of PVDF by adding MCC-TEOS weight contents endowed the 3 wt% MCC/TEOS-based PVDF separator membrane with superior electrolyte absorption and reduced resistance, resulting in an impressive ionic conductivity of 0.514 mS/cm higher than the pristine PVDF membrane (0.253 mS/cm). Furthermore, the LIB cell utilizing the 3 wt % MCC/TEOS-based PVDF separator membrane consistently demonstrated stable charge/discharge profiles at a rate of 0.2C, achieving a specific capacity of 98 mAh/g, compared to only 43 mAh/g for the pristine PVDF membrane. These findings underscore the significant potential of MCC/TEOS as a biofiller for bio-membranes, making it an optimal choice for applications in LIBs.

Pervaporation emerges as a promising technique for brine treatment. In this investigation, we employed a PVDF substrate layer and applied various coating solutions using a simple spray technique to produce a composite pervaporation membrane. The composite membrane's chemical structure, morphology, hydrophilicity, swelling property, surface roughness, and crosslinking conditions were thoroughly investigated. Notably, the PVDF/PEI/P(SS-MA) composite membrane exhibited outstanding desalination performance, demonstrating high salt rejection and flux of 308.7 ± 13.8 kg m−2 h−1 when subjected to a 3.5 wt% sodium chloride solution. Even at an elevated brine concentration of 20 wt%, the membrane maintained a commendable flux of 88.76 ± 5.4 kg m−2 h−1 at 72 °C. These findings underscore the efficacy of the developed composite membrane for brine desalination applications.

Cellulose nanofibers (CNFs) are a kind of natural macromolecules. Carbonized cellulose nanofiber (C-CNF) can be obtained by carbonizing CNFs, whose structure is similar to that of graphite. When C-CNFs are used in the assembly of graphene and polyvinylidene fluoride (PVDF) membranes, the electric heating membranes with high performance and a stable stacking structure can be constructed. Graphene/C-CNF/PVDF (GCP) dispersion was prepared using the solution blending method, and GCP membrane was prepared with the vacuum drying method. The results show that the resistance of the GCP membrane is controlled at about 40.6–74.6 Ω, which is a little different from that of the graphene/PVDF membrane (89 Ω). The equilibrium temperatures of the GCP membranes with different graphene mass fractions increase linearly with the increase of voltage. The GCP-03 membrane reached 158 °C quickly at 6 V, which is the highest temperature compared to other membranes. From the infrared thermography, it is clear that the GCP membranes have excellent electrical and thermal properties, good thermal stability, and uniform heat distribution, which will allow functional textiles to play a greater role in various fields such as aerospace and industry. [ABSTRACT FROM AUTHOR]

Hypertension is a common cause of cardiovascular diseases, closely associated with the high mortality and disability rates of cardiovascular diseases such as stroke and coronary heart disease. Therefore, developing a comfortable and sustainable device for monitoring human pulse signals holds practical significance for the prevention and treatment of hypertension and cardiovascular diseases. PVDF flexible pressure sensors possess the characteristics of high sensitivity, good flexibility, and strong biocompatibility, thereby demonstrating extensive application potential in areas such as health monitoring, wearable devices, and electronic skins. This paper focuses on the development of a modified piezoelectric polymer and its application in an intelligent blood pressure monitoring system, demonstrating its outstanding performance and feasibility through a series of experiments. This research provides innovative material choices for the development of intelligent medical devices and offers beneficial guidance for the design and application of future intelligent health monitoring systems. [ABSTRACT FROM AUTHOR]

Portable power is an effective solution to realize self-powered sensors for wearable devices, promoting future sustainable development. Membrane-based triboelectric nanogenerators (M-TENGs) have emerged as a promising technology for harvesting biomechanical energy from human motion owing to their advantages, such as simple structure, lightweight design, and efficient energy conversion. However, the poor durability, low adaptability, and un-washability of two-dimensional membrane materials have largely hindered their application in wearable electronics. In this study, we propose a sheath–core polyvinylidene fluoride (PVDF)/graphene (G)-carbon fiber (CF) yarn fabricated via conjugate electrospinning, comprising a commercial CF core and an electrospun graphene-doped PVDF sheath, which improves the fatigue resistance of electrospun nanofiber films under prolonged friction and keeps a high degree of freedom. The resulting electronic textile, woven with the large-scale electrospun PVDF/G-CF yarn, demonstrates a remarkable power density of 25.5 mW·m−2. The tight distribution of PVDF/G nanofibers on the textile surface ensures excellent softness, washability, and durability. Furthermore, the electrospun PVDF/G-CF textile exhibits significant potential in pressure sensing, self-powered operation, and motion detection, making it highly suitable for wearable electronics applications. [ABSTRACT FROM AUTHOR]

With the increasing demand for self-adaptive electronics, stretchable and conformable sensors with high sensitivity, stretchability, and self-adhesive are significant intelligent devices. Here a novel tactile sensor is demonstrated that maintains conformal contact to the object for efficient movement monitoring. The device, which was composed of the "H" well-manicured thermoplastic elastomer (TPE), a rectangular polyvinylidene fluoride (PVDF) film coupled with a silver electrode and clamped into the copper-clad signal line ends, and a "U" shaped super-elastic silica gel layer, provided satisfactory performance. The device was investigated as a dynamic monitoring sensor due to its stretchable and conformal configuration. The mechanical stability and high sensitivity suggested that, when attached to the skin of participants, the sensor detected motion induced strain which was experimentally demonstrated. The results show that the novel biomimetic sensor is effective in monitoring human dynamics, with an accuracy exceeding than 98.3%. The stretchable and conformable sensor is low-cost and nontoxic with potential applications in clinical, conformal detection, and artificial intelligence. [ABSTRACT FROM AUTHOR]

Abstract The rising widespread oil‐impacted wastewater warrants an urgent call for innovative approaches to the handling of oily wastewater. A variety of techniques has been investigated to treat oil‐impacted water, and they are found to be inefficient. Electrospun nanofibers emerge as the viable technique to treat oily wastewater precisely owing to their high specific surface areas and interconnected nanoscale pore structures. In this review, a brief background on the study is provided followed by the environmental pollution by the oily wastewater. Subsequent to that, the polyvinylidene fluoride (PVDF) modification methods are also presented followed by the physicochemical properties of both the electrospun PVDF blends and the PVDF‐based composites. Furthermore, the performances of the PVDF‐based composites in oil/water separation are described. It is concluded with the future prospects for using PVDF‐based composites for oil/water separation.

Given global water scarcity and the quest for sustainable energy, there's a pressing need for integrated approaches addressing water‐energy interdependence worldwide. A practical approach for this challenge involves the implementation of fog water collectors. Herein, a polyvinylidene fluoride (PVDF) multifunctional device capable of harvesting water and electricity from wind is developed and tested, collecting up to 365 mg cm−2 h−1 of fog water. Due to the piezoelectric nature of electrospun PVDF, these yarns and meshes not only serve as piezoelectric sensors, enabling the detection of incoming fog flow and determination of its speed and, bust also harvest electricity by charging a capacitor, making it a green and renewable power source. In this study, promising insights are offered into developing efficient fog water collection methods and utilizing piezoelectric fiber‐based yarns and meshes for multifunctional applications in sustainable water management, energy harvesting, and sensing in a single device.

In this work, we designed a novel polyvinylidene fluoride (PVDF)@DNA solid polymer electrolyte, wherein DNA, as a plasticizer-like additive, reduced the crystallinity of the solid polymer electrolyte and improved its ionic conductivity. At the same time, due to its Lewis acid effect, DNA promotes the dissociation of lithium salts when interacting with lithium salt anions and can also fix the anions, creating more free lithium ions in the electrolyte and thus improving its ionic conductivity. However, owing to hydrogen bonding between DNA and PVDF, excess DNA occupies the lone pairs of electrons of the fluorine atoms on the PVDF molecular chains, affecting the conduction of lithium ions and the conductivity of the solid electrolyte. Hence, in this study, we investigated the effects of adding different DNA amounts to solid polymer electrolytes. The results show that 1% DNA addition resulted in the best improvement in the electrochemical performance of the electrolyte, demonstrating a high ionic conductivity of 3.74 × 10−5 S/cm (25 °C). The initial capacity reached 120 mAh/g; moreover, after 500 cycles, the all-solid-state batteries exhibited a capacity retention of approximately 71%, showing an outstanding cycling performance.

The notch effect of semicrystalline PVDF was investigated using U- and V-notch geometries with different depths, and tensile tests were performed at 23 °C using the DIC technique and FEA. Both unnotched and notched dumbbell-shaped specimens were subjected to tensile loading with the DIC technique to obtain mechanical curves and strain maps. The experimental data were compared to a numerical model, analyzing both global mechanical curves and local strain maps around the notch region to assess the accuracy of the simulations. The results demonstrated that the geometry and depth of the notch influence the mechanical behavior of PVDF, presenting a decrease in load and displacement compared to unnotched specimens. This aspect was corroborated by strain maps, which showed the increase in the local strain around the notch tip. For FEA, the global analysis indicated a good correlation with experimental results, and the local analysis demonstrated a reasonable agreement in strain map results within 0.5 mm of the notch neighborhood. Overall, the DIC technique and FEA provided a reliable evaluation of notch behavior on the PVDF used as pressure sheaths with reasonable precision.

The crystal structure has a great influence on the dielectric and piezoelectric performance of poly(vinylidene fluoride) (PVDF). In this work, we prepared PVDF films with two typical crystalline phases (α and β). In situ Kelvin probe force microscopy (KPFM) and Piezoelectric force microscopy (PFM) were employed to investigate the responses of different PVDF crystalline phases to charge mobility, polarization, and piezoelectric properties. We used a homemade Kelvin probe force microscope (KPFM) to inject charges into the two crystalline phases to investigate the differences in the response of different crystalline phases of PVDF to electrical excitation on a microscopic scale. It was found that the α-phase has a lower charge injection barrier and is more susceptible to charge injection and that the α-phase is accompanied by a faster charge dissipation rate, which makes it easier to accumulate charge at the interface between the α-phase and β-phase PVDF. Moreover, the PFM polarization manipulation showed no change in the amplitude and phase diagram of the α-phase under ±10 V bias. In contrast, the β-phase showed a clear polarization reversal phenomenon and a significant increase in piezoelectric amplitude, which is consistent with its polar intrinsic properties. This study provides valuable insights into the multiphase contributions and a reference for designing advanced PVDF dielectrics.

Polyvinylidenefluoride (PVDF) is a semi‐crystalline ferroelectric polymer with a wide range of interesting properties and shows potentiality in a variety of technological applications. Flexible thin films of PVDF nanocomposites (NCs) have attracted many researchers due to their tunable electronic properties. This paper reports the synthesis, characterization, and dielectric studies of PVDF‐TiO2 NC thin films. The synthesized films are self‐supporting thin and the average thickness of the thin films is 60 µm measured using a Digital thickness gauge of resolution 0.01 mm. TiO2 nanoparticles are prepared using the combustion method. Commercially available PVDF granules are used to develop PVDF‐TiO2 NC thin films using the film casting technique. The structural study of the prepared thin films is carried out using XRD that confirms the retention of the β‐phase of PVDF. The functional group and bonding nature have been studied using FTIR Spectroscopy. The thermal stability of the NC thin films is studied using TGA. The variation of dielectric constant (DC), dielectric loss (DL), AC conductivity, and dissipation factor of the medium of pristine PVDF and PVDF‐TiO2 NC thin films are studied in the frequency range of 10 Hz to 8 MHz at ambient temperature. The dielectric constant of PVDF‐TiO2 NC thin films increases up to 8 wt% and anomaly for 10 wt% of TiO2 fillers in the PVDF matrix at a lower frequency and found to decrease with increasing frequency. The dielectric loss of NC thin films is high at a lower frequency and decreases with an increase in the frequency that is in good agreement with the Maxwell–Wagner type of interfacial polarization. At lower frequencies, the dielectric constant of PVDF‐TiO2 NC increases with the increase in filler content. AC conductivity shows a sharp increase at higher frequencies whereas the dissipation factor of the polymer NCs remains unaltered with respect to frequency by maintaining the trend. This suggests that PVDF‐TiO2 NC is potential material for energy storage devices. [ABSTRACT FROM AUTHOR]

Despite the well-established nature of non-destructive testing (NDT) technologies, autonomous monitoring systems are still in high demand. The solution lies in harnessing the potential of intelligent structures, particularly in industries like aeronautics. Substantial downtime occurs due to routine maintenance, leading to lost revenue when aircraft are grounded for inspection and repairs. This article explores an innovative approach using intelligent materials to enhance condition-based maintenance, ultimately cutting life-cycle costs. The study emphasizes a paradigm shift toward structural health monitoring (SHM), utilizing embedded sensors for real-time monitoring. Active thin film piezoelectric materials are proposed for their integration into composite structures. The work evaluates passive sensing through acoustic emission (AE) signals and active sensing using Lamb wave propagation, presenting amplitude-based and frequency domain approaches for damage detection. A comprehensive signal processing approach is presented, and the damage index and damage size correlation function are introduced to enable continuous monitoring due to their sensitivity to changes in material properties and defect severity. Additionally, finite element modeling and experimental validation are proposed to enhance their understanding and applicability. This research contributes to developing more efficient and cost-effective aircraft maintenance approaches through SHM, addressing the competitive demands of the aeronautic industry. [ABSTRACT FROM AUTHOR]

Nanofiber (NF) products exhibit outstanding performances in materials science, textiles, and medicine that cannot be realized using conventional technologies. However, the safety of such products is debated because of the potential health risks that nanomaterials pose and the lack of standardized guidelines for the safety evaluation of NF products. The global safety evaluations of nanomaterials have focused on evaluating the cytotoxicity of low-dimensional materials, including nanoparticles and nanotubes, based on OECD (Organization for Economic Co-operation and Development) criteria. NFs are one-dimensional materials with nanometer diameters and considerable lengths. Many fibers are applied in a densely woven web-like form, so assessing cellular penetration and fiber toxicity using the same methods is inappropriate. This study verifies the safety of the polyurethane (PU) and polyvinylidene fluoride (PVDF) polymers currently applied in filters and masks. To this end, polymer NFs were collected from each product, and the NFs were compared with reference samples using FT-IR and Raman spectroscopy. For the safety evaluation, DMSO stocks of varying concentrations of PVDF and PU NFs (at 0.5, 1, 5, and 10 μg/mL) were prepared. The cytotoxicity and inhibitory effects on nitric oxide production and protein expression obtained via Western blot were identified. [ABSTRACT FROM AUTHOR]

The effect of content in the piezoelectric response of poly (vinylidene fluoride) (PVDF)/BaTiO3 nanocomposites has been investigated in this work. The morphology of PVDF-BaTiO3 composite films was characterized using scanning electron microscopy (SEM). Fourier transforms infrared (FTIR) spectroscopy and X-ray diffractometry (XRD) were used to investigate the phase analysis of samples. Voltage output increases significantly with increasing filler content. The electroactive ß-phase of PVDF is nucleated by the presence of the ceramic filler, the effect being strongly dependent on filler content. The results revealed that incorporating the functionalized BaTiO3 nanoparticles within the PVDF layer increases the piezoelectric response of pure PVDF compared to the sample with incorporated pure sample. Increasing concentration caused enhanced piezoelectric response. [ABSTRACT FROM AUTHOR]

Abstract Background The textile industry represents a great portion of the global industry due to the increase in population and demand for sustainable products. Tons of textile wastewater contain predominantly synthetic complex organic dyes like direct dyes, processing dyes, reactive dyes, etc., making discharge of colored effluents challenging. Main body of the abstract Textile wastewater treatment is essential to maintain the environmental balance and reduce public health threats. Conventional wastewater treatment methods cannot overcome and decompose these toxic wastes; therefore, numerous modern approaches have been studied and implemented for pollutant degradation to be suitable for environmental disposal. Membranes and photocatalysis have proven their significant effect on the photodegradation of different dyes and the production of pure water for further use in industrial purposes. Short conclusion This review paper aims to represent a comprehensive review of textile dyeing wastewater treatment by integrating polyvinylidene fluoride (PVDF) and titanium dioxide (TiO2) in a hybrid system named “photocatalytic membrane reactor, PMR”.

Currently, one of the priority tasks is the development of intelligent materials that are sensitive to stimuli and can be used in catalytic applications for efficient decomposition of organic pollutants. Particularly relevant in this regard is the development of inexpensive non‐metallic hybrid polymer photocatalysts, and the explanation of the mechanism of using light energy in such systems is still the subject of open discussions. In this work, hybrid polymer fiber membranes based on polyvinylidene fluoride (PVDF) with graphite flakes were obtained by electrospinning. The morphology of the obtained samples was investigated using SEM microscopy methods, and their crystalline structure was analysed using XRD, Raman, and FTIR methods. Using RFE spectroscopy, it was shown that the addition of graphite leads to ion‐dipole interaction between the carbon surface and the polymer dipoles, changing the ratio of covalent and semi‐ionic bonds on the surface. The catalytic properties investigated during the decomposition of the organic dye methylene blue (MB) demonstrated high piezocatalytic activity of doped membranes and high photocatalytic activity of PVDF/C0.5. It was established that the photocatalytic activity is due to excitonic excitation. [ABSTRACT FROM AUTHOR]

The non‐solvent induced phase separation technology was introduced to formulate titanium dioxide (TiO2)‐hydroxyapatite (HAP) composite modified polyvinylidene fluoride (PVDF) ultrafiltration (UF) membranes, and research was conducted to explore the effect on PVDF UF membrane performance exerted by different addition amounts (0–1.0 wt%) of TiO2‐HAP composite. The results indicated that when 0.3% TiO2‐HAP composite was added, the composite membranes had a through‐channel structure, with a uniform pore structure on the surface, so that they possessed a certainly raised pure water flux. Specifically, in contrast to the pure PVDF membrane, 0.3%‐TiO2‐HAP@PVDF UF membrane exhibited an incremented pure water flux by 59.09%. Besides, TiO2‐HAP@PVDF UF membranes had decreased rejection rate of bovine serum albumin (BSA) together with water contact angle to 58.62% and 70.17°, respectively, compared to the pure PVDF membrane (85.52% & 92.75°), showing good hydrophilicity. Several pure water flux tests on the composite UF membranes revealed that the flux tended to be stable after the 4th test. In summary, the addition of TiO2‐HAP composite is capable of efficiently ameliorating PVDF base membranes from the aspects of microstructure, hydrophilicity, antifouling properties, as well as stability, allowing a good application prospect in actual water treatment. Highlights: The HAP can solve the poor adsorption of TiO2.The TiO2 can improves the interfacial adhesion between HAP and polymer.The TiO2‐HAP composite with excellent stability, corrosion resistance and et al.The TiO2‐HAP@PVDF UF membrane with anti‐pollution performance and stability. [ABSTRACT FROM AUTHOR]

Background: The textile industry represents a great portion of the global industry due to the increase in population and demand for sustainable products. Tons of textile wastewater contain predominantly synthetic complex organic dyes like direct dyes, processing dyes, reactive dyes, etc., making discharge of colored effluents challenging. Textile wastewater treatment is essential to maintain the environmental balance and reduce public health threats. Conventional wastewater treatment methods cannot overcome and decompose these toxic wastes; therefore, numerous modern approaches have been studied and implemented for pollutant degradation to be suitable for environmental disposal. Membranes and photocatalysis have proven their significant effect on the photodegradation of different dyes and the production of pure water for further use in industrial purposes. Short conclusion: This review paper aims to represent a comprehensive review of textile dyeing wastewater treatment by integrating polyvinylidene fluoride (PVDF) and titanium dioxide (TiO2) in a hybrid system named "photocatalytic membrane reactor, PMR". [ABSTRACT FROM AUTHOR]

Abstract Although technologies and processes for creating smart composite structures have been established, significant limitations still necessitate additional research to overcome. Indeed, numerous studies have highlighted the challenges of embedding active elements, often leading to compromises in the structural integrity of smart composite materials. In contrast, this study introduces a novel perspective, offering innovative insights and valuable contributions to the existing knowledge. The primary contribution of this study lies in addressing the critical need for the seamless integration of active materials within composite structures. To demonstrate this, our study considers the potential integration of Polyvinylidene Fluoride (PVDF), a polymer-based piezoelectric material, with pre-impregnated unidirectional flax fibers to produce a smart composite structure. The consolidation molding process was adopted to manufacture the smart composite samples for investigations. Experimental analysis were then considered to evaluate the influence of the embedded PVDF film on the mechanical performance of the structure and to assess the resulting functional properties. X-ray micro-computed tomography and an additional strength-of-material test approach, Interlaminar Shear Strength (ILSS), were performed to explore the impact of the insertion on the integrity of the laminate structure. On the other hand, we conducted vibration tests to assess the electromechanical properties. The tomography results reveal void elimination in the edges of the active material insert, which could be attributed to the choice of thin film materials. Moreover, the ILSS results highlight the minimal impact of PVDF material on mechanical performance, showcasing a mere 0.69% degradation of the material strength. These results are comparable to the recently reported works but with an appreciable margin of improvement. The vibration test response demonstrates the ability of the embedded piezoelectric material to generate voltage, which validates our integration procedure. The smart composite material’s sensitivity to ambient vibrations and its power generation potential show promise for sensing and energy harvesting. [ABSTRACT FROM AUTHOR]

The polyethylene lithium-ion battery separator is coated with a polymer by means of a roll-to-roll (R2R) gravure coating scheme to enhance the thermal stability. The polyvinylidene fluoride (PVDF) or polyvinylidene fluoride-co-hexafluoropropylene (PVDF-HFP) is gravure-coated, and the pores are fabricated based on online nonsolvent-induced phase separation (NIPS). N-methylpyrrolidone is used as a solvent, and deionized water or a methanol mixture thereof is exploited as a nonsolvent in NIPS. Scanning electron microscopy confirms that the polymer film is formed and that the pores are well developed. The thermal shrinkage decreased by 20.0% and 23.2% compared to that of the bare separator due to the coating of PVDF and PVDF-HFP, respectively. The R2R gravure coating scheme is proven to be fully functional to tailor the properties of lithium-ion battery separators. [ABSTRACT FROM AUTHOR]

Hypertension is a common cause of cardiovascular diseases, closely associated with the high mortality and disability rates of cardiovascular diseases such as stroke and coronary heart disease. Therefore, developing a comfortable and sustainable device for monitoring human pulse signals holds practical significance for the prevention and treatment of hypertension and cardiovascular diseases. PVDF flexible pressure sensors possess the characteristics of high sensitivity, good flexibility, and strong biocompatibility, thereby demonstrating extensive application potential in areas such as health monitoring, wearable devices, and electronic skins. This paper focuses on the development of a modified piezoelectric polymer and its application in an intelligent blood pressure monitoring system, demonstrating its outstanding performance and feasibility through a series of experiments. This research provides innovative material choices for the development of intelligent medical devices and offers beneficial guidance for the design and application of future intelligent health monitoring systems.

Piezoelectric nanogenerators have prospective uses for generating mechanical energy and powering electronic devices due to their high output and flexible behavior. In this research, the synthesis of the three-dimensional coral-like BaTiO3 (CBT) and its filling into a polyvinylidene fluoride (PVDF) matrix to obtain composites with excellent energy harvesting properties are reported. The CBT-based PENG has a 163 V voltage and a 16.7 µA current at a frequency of 4 Hz with 50 N compression. Simulations show that the high local stresses in the CBT coral branch structure are the main reason for the improved performance. The piezoelectric nanogenerator showed good durability at 5000 cycles, and 50 commercial light-emitting diodes were turned on. The piezoelectric nanogenerator generates a voltage of 4.68–12 V to capture the energy generated by the ball falling from different heights and a voltage of ≈0.55 V to capture the mechanical energy of the ball's movement as it passes. This study suggests a CBT-based piezoelectric nanogenerator for potential use in piezoelectric sensors that has dramatically improved energy harvesting characteristics. [ABSTRACT FROM AUTHOR]

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Xinyang Normal University Natural Science Edition is the property of Journal of Xinyang Normal University Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Piezoelectrics & Acoustooptics is the property of Piezoelectric & Acoustooptic and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Nanomaterials, including nanofibers, have emerged as promising drug delivery systems with a wide range of pharmaceutical applications. In the present study, a nanofiber-based scaffold has been fabricated for ginger oil's formulation. The scaffold formula is composed of ginger oil (encapsulated) within poly(vinylidene fluoride) nanofiber (GIN@PVDF). The scaffold was prepared using electrospinning technique and its structure was confirmed using scanning electron microscopy, FTIR spectroscopic analysis, contact angle measurement, and thermogravimetric analysis. Prepared formula showed higher safety profile against human normal cells (Wi-38), while retained the anticancer effect of the free ginger oil against the Huh-7 liver cancer and the MDA-MB-231 triple-negative breast cancer cells. Moreover, the prepared scaffold showed superior antioxidant potential, as evident by its ability to further activate the transcription of the redox mediator Nuclear factor erythroid-2-related factor 2 (NrF2) compared to the free ginger oil. Furthermore, insignificant difference was observed between the apoptotic effects of GIN-free and GIN@PVDF against MDA-MB-231 cells. Therefore, the novel nanofiber scaffold provides promising potential for the preparation of ginger oil-based pharmaceutical formula for anticancer treatment area. [ABSTRACT FROM AUTHOR]

A novel type of Janus polyvinylidene fluoride/deacetylated cellulose acetate (PVDF/D‐CA) nanofiber membrane with multifunctional application is successfully fabricated by sequential electrospinning. The morphology, chemical composition, surface wettability, oil–water separation performance, and unidirectional liquid transmission capability have been systematically analyzed. It has asymmetric wettability property in air and in liquid systems for its bottom and top sides. It can be used as a water‐removing, or oil‐removing substance for oil–water mixture and emulsion under a harsh environment only under gravity driving force (DF) by simply switching the different sides. It possesses on‐demand water and oil collection ability, and moisture‐wicking performance due to its switchable permeation and unidirectional liquid transmission capability. Its multifunction application can be easy to control by adjusting the thickness of the top and bottom sides through controlling the electrospinning time. Its excellent mechanical property, chemical stability, durability under harsh environment and outstanding anti‐pollution ability endow the membrane with powerful cyclic stability and reusability. [ABSTRACT FROM AUTHOR]

Copyright of Piezoelectrics & Acoustooptics is the property of Piezoelectric & Acoustooptic and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Generally speaking, the aerodynamic force generated by each component will hinder the endurance and performance of the UAV. In addition, because PVDF has the characteristics of high flexibility, corrosion resistance and nontoxic, a wind resistance pro-filed sensor based on polyvinylidene fluoride (PVDF) is developed, which can be used to measure the resistance of UAV in different directions. The sensor consists of nine surfaces, which can measure the resistance caused by wind in different directions at the same time. By analyzing the average output voltage collected under different wind speeds and flight states, the resistance of different UAV propellers is estimated. This research is helpful to improve the structure of UAV, reduce the impact of drag, and increase the UAV's endurance time and carrying capacity. [ABSTRACT FROM AUTHOR]

A lithium-ion battery with PVDF-PEO synthetic polymer sheet added by LiTFSI electrolyte salt has been made by assembling method. This study aims to determine the effect of LiTFSI salt concentration on the performance of lithium-ion batteries. The composition of LiTFSI electrolyte salts was varied into 5%; 10%; 15%; and 20%. Several characterizations were carried out to determine battery performance, including Electrochemical Impedance Spectrometry (ElS), Cyclic Voltammetry (CV), Charge/Discharge (CD), and Lithium Transference Number (LTN). The results showed that the synthesized separator sheet with a LiTFSI salt composition of 20% producing voltage, ionic conductivity, and lithium-ion transfer number of 0.72 V; 3.94 x 10-8 SCm-1; and 0.895, respectively is potential for lithium-ion batteries application. These results indicate the use of LiTFSI electrolyte salts with a concentration of 20% shows the best performance for PVDF-PEO-LiTFSI-based lithium-ion batteries. [ABSTRACT FROM AUTHOR]

Nanofiber (NF) products exhibit outstanding performances in materials science, textiles, and medicine that cannot be realized using conventional technologies. However, the safety of such products is debated because of the potential health risks that nanomaterials pose and the lack of standardized guidelines for the safety evaluation of NF products. The global safety evaluations of nanomaterials have focused on evaluating the cytotoxicity of low-dimensional materials, including nanoparticles and nanotubes, based on OECD (Organization for Economic Co-operation and Development) criteria. NFs are one-dimensional materials with nanometer diameters and considerable lengths. Many fibers are applied in a densely woven web-like form, so assessing cellular penetration and fiber toxicity using the same methods is inappropriate. This study verifies the safety of the polyurethane (PU) and polyvinylidene fluoride (PVDF) polymers currently applied in filters and masks. To this end, polymer NFs were collected from each product, and the NFs were compared with reference samples using FT-IR and Raman spectroscopy. For the safety evaluation, DMSO stocks of varying concentrations of PVDF and PU NFs (at 0.5, 1, 5, and 10 μg/mL) were prepared. The cytotoxicity and inhibitory effects on nitric oxide production and protein expression obtained via Western blot were identified.

Abstract Improving the energy storage density of dielectric capacitors has absorbed extensive attention for energy storage. However, a decrease in breakdown strength may be aroused after the addition of abundant fillers, it is necessary to design the composite film with a sandwich structure without the sacrifice of mechanical properties. The PPy‐TiO2/PVDF monolayer film and PVDF/PPy‐TiO2/PVDF sandwich‐structured composite films were successfully prepared via electrospinning and a hot‐press treatment. The experiment results show that the dielectric constant of the composite films can be enhanced effectively by adding PPy‐TiO2.When the filling amount is 30 wt%, the energy storage density of PVDF/PPy‐TiO2/PVDF sandwich‐structured composite films is outstanding before the breakdown strength, which is higher than that of the pure PVDF film. The energy storage density of PVDF/PPy‐TiO2/PVDF sandwich‐structured composite films could be achieved to 2.68 J/cm3 under the electric strength of 1700 kV/cm.

Abstract A novel type of Janus polyvinylidene fluoride/deacetylated cellulose acetate (PVDF/D‐CA) nanofiber membrane with multifunctional application is successfully fabricated by sequential electrospinning. The morphology, chemical composition, surface wettability, oil–water separation performance, and unidirectional liquid transmission capability have been systematically analyzed. It has asymmetric wettability property in air and in liquid systems for its bottom and top sides. It can be used as a water‐removing, or oil‐removing substance for oil–water mixture and emulsion under a harsh environment only under gravity driving force (DF) by simply switching the different sides. It possesses on‐demand water and oil collection ability, and moisture‐wicking performance due to its switchable permeation and unidirectional liquid transmission capability. Its multifunction application can be easy to control by adjusting the thickness of the top and bottom sides through controlling the electrospinning time. Its excellent mechanical property, chemical stability, durability under harsh environment and outstanding anti‐pollution ability endow the membrane with powerful cyclic stability and reusability.

Polyvinylidene fluoride (PVDF) nano-composites are known for the harmonious effect of flexibility, biocompatibility, formability, toughness, higher fatigue life, and piezoelectric properties. Nevertheless, little has been reported on the comparison of mechanical blending (MB) and chemical-assisted mechanical blending (CAMB) of PVDF-BaTiO3-graphene (Gr) nano-composites. This paper reports the comparison of mechanical, thermal, morphological, and 4D properties of PVDF-BaTiO3-Gr nano-composites prepared by MB and CAMB for piezoelectric-based pressure sensors and nanogenerators. In the first stage, feedstock filaments of PVDF-BaTiO3-Gr nano-composites got prepared by MB and CAMB. After this, the effect of blending process parameters on mechanical, thermal, and morphological properties got established on 3D-printed tensile, flexural, and dynamic mechanical analysis samples at optimized settings of fused deposition modeling setup (in the second stage). The results have been supported by Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), X-ray diffraction (XRD), and differential scanning calorimetry (DSC) analysis. The DSC analysis suggested that the PVDF-BaTiO3-Gr nano-composite prepared by MB is thermally more stable than CAMB, as the MB composites absorbed more heat (31.09 J/g) in comparison with the CAMB composite (26.59 J/g). On the other hand, the piezoelectric coefficient (D33) of the dielectric constant of CAMB-based samples was 30.2pC/N, 55, respectively, better than MB (20.1pC/N, 18). Also, results indicated that 3D-printed functional prototypes prepared by CAMB have better mechanical and morphological properties. [ABSTRACT FROM AUTHOR]