Polyvinylidene Fluoride Fibers Research Articles

Graphene-Doped Piezoelectric Transducers by Kriging Optimal Model for Detecting Various Types of Laryngeal Movements.

This study fabricated piezoelectric fibers of polyvinylidene fluoride (PVDF) with graphene using near-field electrospinning (NFES) technology. A uniform experimental design table U*774 was applied, considering weight percentage (1-13 wt%), the distance between needle and disk collector (2.1-3.9 mm), and applied voltage (14.5-17.5 kV). We optimized the parameters using electrical property measurements and the Kriging response surface method. Adding 13 wt% graphene significantly improved electrical conductivity, increasing from 17.7 µS/cm for pure PVDF to 187.5 µS/cm. The fiber diameter decreased from 21.4 µm in PVDF/1% graphene to 9.1 µm in PVDF/13% graphene. Adding 5 wt% graphene increased the β-phase content by 6.9%, reaching 65.4% compared to pure PVDF fibers. Material characteristics were investigated using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction analysis (XRD), contact angle measurements, and tensile testing. Optimal parameters included 3.47 wt% graphene, yielding 15.82 mV voltage at 5 Hz and 5 N force (2.04 times pure PVDF). Force testing showed a sensitivity (S) of 7.67 log(mV/N). Fibers were attached to electrodes for piezoelectric sensor applications. The results affirmed enhanced electrical conductivity, piezoelectric performance, and mechanical strength. The optimized piezoelectric sensor could be applied to measure physiological signals, such as attaching it to the throat under different conditions to measure the output voltage. The force-to-voltage conversion facilitated subsequent analysis.

Study of the electrospun PVDF fibrous membrane in capturing particulate matters in smoke by the synergy between GO and CNWs

The filtration capability can be effectively adjusted by involving the incorporation of fillers into filter materials. Here, we present a promising filter material for capturing particulate matters in smoke, a polyvinylidene fluoride (PVDF) fibrous membrane modified by cellulose nanowhisker (CNWs) and graphene oxide (GO), which was prepared by a facile electrospinning method. GO with oxygen-containing groups can improve the capability of capturing particle owing to its excellent adsorption performance. CNWs with highly ordered crystalline regions can alter the dimension and properties of PVDF fibers. The synergistic effect of GO and CNWs enabled uniform fiber diameter, higher porosity, and better filtration property as compared with that of pristine PVDF membranes. Experimental results demonstrated a significant improvement in the filtration efficiency of PVDF fibrous membranes after blending with GO and CNWs. The filtration data showed that the filtration efficiency (95.58%) of GO/CNWs/PVDF membrane was higher than that (87.68%) of CNWs/PVDF membrane and that (86.36%) of PVDF membrane. The reusability for capturing pollutants showed that the fibrous membrane could keep a certain filtration capability (93.85%) after 5 cycles. Computational results suggested there was an interaction between GO and smoke pollutants (monoterpene) and the addition of GO play an effect on the filtration efficiency of fibrous membranes. These results showed that GO/CNWs/PVDF fibrous membranes was ideal filter materials for air pollutant.

Wash‐stable electrospun piezopolymer textiles

AbstractSmart textiles are currently being pursued for actuation and sensing for their potential to directly incorporate “intelligence” into the fabric, in contrast to wearable technologies. In smart textiles, smart materials (e.g., piezoelectric) are formed into yarns that are woven into fabrics for clothing. One immediate requirement for such textiles is their stability during washing cycles, as expected of any clothing items, which has been largely lacking so far. Here, we investigate the washing stability of nanofibrous piezoelectric textiles. Our results reveal that electrospun textiles exhibit remarkable structural stability from the fiber microstructure to the textile level. Overall fiber crystalline composition and electroactive phase remain stable within 1% of ~47% and ~85%, respectively. Mechanically, the textile displays sustained performance, with only negligible changes observed. The yield strain and stress only show a ~8% and 9% differences, respectively. Moreover, piezoelectric stability is confirmed through phase preservation and slight variation in voltage output of ~6%. These results prove the candidacy that the processing of electrospun polyvinylidene fluoride (PVDF) fibers to woven textiles is applicable to the demands of smart textiles, which is expected to accelerate the commercialization of such textiles for wearable robotics and health monitoring.

Correlation of Dielectric Properties and Vibrational Spectra of Composite PVDF/Salt Fibers.

Nitride salts were added to polyvinylidene fluoride fibers and then the fiber mats were prepared by electrospinning. An experimental investigation of the structure was provided by Raman, FTIR, SEM, and XRD. The phase ratio of the polymer was studied both theoretically and experimentally in connection with the addition of the hydrates Mg(NO3)2, Ca(NO3)2, and Zn(NO3)2 salts. The comparison of simulated and experimental data for vibrational spectroscopies is discussed. We provide a comparison of triboelectric, dielectric, and compositional characterization of PVDF fibers doped with three types of nitride hydrates. Doping of PVDF fibers with magnesium nitrate hexahydrate leads to significant improvement of the triboelectric performance.

Electrospinning of porous polyvinylidene fluoride microspheres alloyed fibrous membrane with enlarged strain for efficient piezoelectric energy harvesting

AbstractPiezoelectric energy harvesters (PEHs) developed from electrospun polyvinylidene fluoride (PVDF) fibers offer flexibility and superior piezoelectric output, making them promising for self‐powered systems and sensors. Nonetheless, the electromechanical conversion efficiency of conventional electrospun PVDF fibers is impeded by their limited pressure‐strain range. Herein, elastic porous PVDF microspheres are introduced in‐situ via electrospinning to craft a piezoelectric membrane with higher compressive strain. The PVDF microspheres are uniformly embedded between the fibers in a sandwich fashion, and their dimension is easily tunable by varying spinning solution's concentration. Moreover, the micropores on the PVDF microspheres created by removing pre‐mixed SiO2 template not only elevates the β crystal content of PVDF to 82.19%, but also improves the compressibility, significantly boosting the piezoelectric output. The microsphere alloyed PVDF PEH delivers a piezoelectric output of 33.0 V and a power density of 8 μW/cm2, over 5.8 times that of conventional electrospun PVDF membrane, and can consistently charge lithium‐ion batteries. Our research unveils a novel strategic path to modify fiber structured PEHs, advancing their applications in self‐powered systems.

Exploring a New Class of PVDF/3‐Aminopropyltriethoxysilane (core) and 2,2‐Bis(hydroxymethyl)butyric Acid (monomer)‐Based Hyperbranched Polyester Hybrid Fibers by Electrospinning Technique for Enhancing Triboelectric Performance

AbstractWith the rapid advancement in sensor technologies, triboelectric nanogenerators (TENGs) have emerged as a promising sustainable power source for intelligent electronics. Herein, fabricated a novel 3‐aminopropyltriethoxysilane (core) and 2,2‐bis(hydroxymethyl)butyric acid (monomer)‐based hyperbranched polyester by facile single‐step polycondensation technique generation 2 (Si‐HBP‐G2). Further, a new class of polyvinylidene fluoride (PVDF) and different weight percentages (0, 5, 10, 15, and 20 wt%) of Si‐HBP‐G2 hybrid fiber blends are prepared by traditional electrospinning technique. The as‐prepared Si‐HBP‐G2 and its blends are well characterized using SEM/EDS, FTIR, NMR, and XRD studies. The influence of Si‐HBP‐G2 content on triboelectric performance in terms of the open circuit potential (VOC) and short circuit current (ISC) is evaluated using aluminum (Al) as a counter electrode. Among them, 15 wt% of Si‐HBP‐G2/PVDF hybrid fiber mat (PG2‐15) exhibits superior electrical performance. Which is almost increased 5.9 times (22–130 V) of VOC and 4.9 times (0.71–3.5 µA) of ISC than PVDF fiber mate. These results reveal the significance of Si‐HBP‐G2 in the triboelectric performance. The optimized TENG device (PG2‐15/Al‐TENG) exhibits a peak power density of 0.2 Wm−2 at 100 MΩ external load. Finally, the PG2‐15/Al‐TENG practically demonstrates real‐time application energy harvesting applications such as powering 100 LEDs and a stopwatch.

Fabricating high-performance biomedical PLLA/PVDF blend micro bone screws through in situ structuring of oriented PVDF submicron fibers in microinjection molding

Poly(l-lactide) (PLLA) is regarded as a polymer with excellent biocompatibility, but its inherent brittleness property greatly restricts its application in the biomedical engineering field. Blending PLLA with other polymers is one of the sufficiently viable methods of property improvement. In this paper, the Poly(l-lactide) (PLLA)/Polyvinylidene fluoride (PVDF) blend was first prepared by melt-compounding, and then microinjection molded into the blend micro bone screw with high strength and toughness. The experimental results show that the PVDF dispersed phases could in situ form the highly oriented fibers with shish-kebab structures under the effect of strong shear stress field of microinjection molding along flow direction. These parallelly aligning PVDF fibers could simultaneously realize the significant enhancement in both toughness and strength of the micro bone screw. Specifically, in the bending test the blend micro bone screw with oriented PVDF fibers can withstand the compression displacement of nearly 2 mm, while the neat PLLA one would break within only 0.5 mm displacement. In addition, a bending recovery phenomenon was observed in the load-displacement curve of the blend, demonstrating the mechanical transition from brittle fracture to ductile fracture. Moreover, with addition of 30 % PVDF, the elongation at break increases from 7.8 % to 57.8 %, while the tensile strength increases from 60.9 MPa to 74.3 MPa. The PLLA/PVDF micro screws possess better toughness and excellent biocompatibility compared to pure PLLA products. They also exhibit great potential for stimulating the proliferation of cells through piezoelectric output, opening up new possibilities for the development of next-generation fracture fixation materials.

A novel centrifugal electrospinning design for preparing of high alignment β-phase PVDF nanofibers for high-performance piezoelectric nanogenerators

The effects of polyvinylidene fluoride (PVDF) wt. % and electric fields on the production of PVDF fibers using a novel centrifugal electrospinning design were investigated. High-quality, bead-free fibers with diameter of (0.55 ± 0.04) μm were successfully produced. Fibers with exceptionally high β-phase content of 96.1 % and piezoelectric coefficient, d33 of (−157 ± 5) pC N−1 were obtained using PVDF amount and electric field of 14.0 wt % and 400 V cm−1, respectively. Under 3.0 N repetitive vertical forces, the fabricated piezoelectric nanogenerator (PENG) exhibited impressive open-circuit voltage, short-circuit current and power density of (32.6 ± 0.7) V, (3.26 ± 0.07) μA and (15.4 ± 0.6) μW cm⁻2, respectively. The production of high and well aligned β-phase in the fibers indicated by good d33 values are the likely reasons for the excellent performance of the PENG. Ultimately, potential of the fabricated PENG as a self-power supply for low-energy electronic devices was demonstrated.

Textured CsPbI3 nanorods composite fibers for stable high output piezoelectric energy harvester

The utilization of piezoelectric nanogenerator (PENG) based on halide perovskite materials has demonstrated significant promise for energy harvesting applications. However, the challenge of synthesizing halide perovskite materials with both high output performance and stability using a straightforward process persists as a substantial obstacle. Herein, we present the fabrication of CsPbI3 nanorods (NRs) exhibiting highly uniform orientation within polyvinylidene fluoride (PVDF) fibers through a simple texture engineering approach, marking the instance of enhancing PENG performance in this manner. The resultant composite fibers showcase a short-circuit current density (Isc) of 0.78 ​μA ​cm−2 and an open-circuit voltage (Voc) of 81 ​V, representing a 2.5 fold increase compared to the previously reported highest value achieved without the electric poling process. This outstanding output performance is ascribed to the orientation of CsPbI3 NRs facilitated by texture engineering and dipole poling via the self-polarization effect. Additionally, the PENG exhibits exceptional thermal and water stability, rendering it suitable for deployment in diverse and challenging environmental conditions. Our findings underscore the significant potential of textured CsPbI3 NRs composite fibers for powering low-power consumer electronics, including commercial LEDs and electronic watches.

Hollow anion-Janus-modified poly(vinylidene fluoride) (PVDF) fiber membranes for nanosized virus removal

In this study, a hollow polyvinylidene fluoride (PVDF) fiber was developed and modified into a Janus membrane (Janus-VM) and an entirely hydrophobic membrane (Hydrophobic-VM) for removing 20-nm-scale viruses during biopharmaceutical processing. The Janus-VM has anionic properties on the outer and feed hydrophilic surfaces, and the inner pore surface (I.P.S) maintains the anionic-hydrophobic properties of the PVDF. Theoretically, an electrostatic repulsion force might be formed between the surface of the strong anionic membrane and anionic bacteriophages, preventing bacteriophages from adsorbing to the membrane surface. As a result, water flux can be increased through the reduction of membrane fouling. The PVDF membrane was modified through UV-irradiation, which causes –OH radicals to form on the membrane surface, and chemical grafting with anionic-hydrophobic/anionic-hydrophilic modifiers, which enhances the membrane’s anion characteristics (−27, −48 mV). Additionally, the average pore size was reduced from 34 nm to less than 20 nm through chemical surface modification, after which the Janus membrane showed an excellent initial water flux, with the protein recovery ratio (PRR) approaching 98.9 %. UV absorbance analysis revealed 100 % removal efficiency for 20- and 40-nm gold particles on the membranes. Furthermore, the initial log reduction value (LRV) was observed through flux performance using MS2 and PP7 bacterial phages, for which the Janus membrane showed an excellent virus removal performance (LRV > 6.8 and 6.5).

Bioinspired construction of petal-like regenerated PVDF/cellulose fibers for efficient fog harvesting

Water collection from atmospheric fog was deemed to be an efficient and sustainable strategy to defuse the freshwater scarcity crisis. Fog harvesting and trapping fibers, therefore, has aroused extensive interest due to their ease of preparation, weave, and use. However, the traditional fibers used in fog collector usually have a low fog collection capacity and efficiency because of their unreasonable morphology and structure design. Herein, we proposed a simple process to construct advanced fibers using a one-step wet spinning of hydrophobic polyvinylidene fluoride (PVDF) and hydrophilic cellulose mixture fiber for fog harvesting. The as-prepared fibers featured a petaloid structure and surface hydrophobic gradient, thus facilitating fog deposition, water droplet formation, and drainage. The unique longitudinal groove structure above enabled the hybrid fiber to achieve an excellent fog collection efficiency of 2750.26 mg/cm2/h per monofilament, which outstripped most of other fiber materials. When woven these fibers were in a longitudinal array network with an interval of 1 mm, and the fog collection efficiency can maintain at 10.30 L/m2/h. Therefore, this work provided a new strategy for further exploration of effective fog collection by cellulose-based fiber materials.

A self-powered piezoelectric Poly(vinyl alcohol)/Polyvinylidene fluoride fiber membrane with alternating multilayer porous structure for energy harvesting and wearable sensors

Development of flexible wearable electronic devices requires high-performance piezoelectric sensors, being advantageous in high sensitivity, ease to microintegration without external power supply. In this work, poly(vinyl alcohol) (PVA)/polyvinylidene fluoride (PVDF) fiber membranes with stable alternating multilayer structure were constructed through electrospinning and subsequent gas-phase crosslinking. The PVA/PVDF fiber was fully stretched with smooth surface and uniform diameter at appropriate PVDF concentration, exhibiting high porosity (88 %). The α-phase was transformed into the electroactive β-phase of PVDF in the electrospinning process, while the crystallinity and β-phase percentage (Fβ) were improved by mixing spinning of PVA and PVDF, with Fβ reaching above 90 %. The PVA/PVDF fiber membrane showed high mechanical strength/toughness and liquid absorbency (719.03 %). The significant electrical signal output (10.07 V and 166.42 nA) was generated, accompanying with high stress sensitivity, short response time and high stability, exhibiting excellent piezoelectricity and making the fiber membrane not only monitor large deformation movements of limbs as self-powered wearable sensor, but also sense weak signals of pulse, breathing etc. for monitoring human health, as well as environmental humidity. Meanwhile, the harvested energy could drive electronic device, showing prosperous potentials in fields of artificial intelligence.

Flexible Magnetocaloric Fiber Mats for Room-Temperature Energy Applications.

Currently, magnetocaloric refrigeration technologies are emerging as ecofriendly and more energy-efficient alternatives to conventional expansion-compression systems. However, major challenges remain. A particular concern is the mechanical properties of magnetocaloric materials, namely, their fatigue under cycling and difficulty in processing and shaping. Nevertheless, in the past few years, using multistimuli thermodynamic cycles with multicaloric refrigerants has led to higher heat-pumping efficiencies. To address simultaneously the challenges and develop a multicaloric material, in this work, we have prepared magnetocaloric-based flexible composite mats composed of micrometric electroactive (EA) polyvinylidene fluoride (PVDF) fibers with embedded magnetocaloric/strictive La(Fe,Si)13 particles by the simple and cost-effective electrospinning technique. The composite's structural characterization, using X-ray diffraction (XRD) analysis, Fourier transform infrared (FTIR) spectroscopy, and measurements of the local-scale piezoresponse, revealed a cubic NaZn13-type structure of the La(Fe,Si)13 phase and the formation of the dominant polar β-phase of the PVDF polymer. The PVDF-La(Fe,Si)13 composite showed an enhancement of the longitudinal piezoelectric coefficient (effective d33) (-11.01 pm/V) compared with the single PVDF fiber matrix (-9.36 pm/V). The main magnetic properties of La(Fe,Si)13 powder were retained in the PVDF-La(Fe,Si)13 composite, including its giant magnetocaloric effect. By retaining the unique magnetic properties of La(Fe,Si)13 embedded in the electroactive piezoelectric polymer fiber mats, we have designed a flexible, easily shapeable, and multifunctional composite enabling its potential application in multicaloric heat-pumping devices and other sensing and actuating devices.

Interaction of material- and structural elasticity – an approach towards a physiological compliance in small-caliber vascular grafts

Research purpose: The low patency rate (less than 50% at a 5-years follow-up) of commercial vascular grafts is strongly associated with compliance mismatch between graft und native artery. To address this deficit, we investigated the influence of the material and structural elasticity on the compliance behavior of small caliber vascular graft gaining for a stress-strain behavior adapted to the native vessel. Material & Methods: By combining different thermoplastic polycarbonate urethanes (TPU) fibers with different elasticity and non-elastic polyvinylidene fluoride (PVDF) fibers in different warp knitted tubular textile structures, we incorporate material and structural elasticity in a vascular graft (I.D. < 6 mm). The evaluation of the tubular fabrics is performed by determining the compliance properties in a mean pressure range between 20 and 120 mmHg by tensile testing. Results: We identified the draw ration of the TPU fiber production, the stitch course density of the fabric and the thread tension of the TPU yarn during the warp knitting process as statistically highly significant effects ( p < .005) on the compliance. With an adapted setting of those parameters, we were able to improve the compliance of the textile vascular grafts over the entire physiological pressure range (20–120 mmHg) by 400–630 % compared to current clinical ePTFE (expanded polytetrafluoroethylene) grafts towards native vessels. Conclusion: By combining material and structural elasticity in a warp knitted textile structure, we were able to biomimic the compliance towards physiological properties. Our approach can be seen as blueprint to adapt elasticity properties in other implant applications.

3D network of zinc powder woven into fibre filaments for dendrite-free zinc battery anodes

Zinc foil metal anodes in aqueous zinc ion batteries (AZIBs) are impaired by uncontrollable dendrite growth, resulting in low Coulombic efficiency (CE) and limited lifetime. The tunability of zinc powder provides a perfect alternative for anodes. But their rough spherical surfaces possibly make them more susceptible to corrosion and dendrite growth. We hereby utilise electrostatic spinning to weave zinc powder into polyacrylonitrile/ Polyvinylidene fluoride (PVDF/PAN) fiber filament to produce a new three-dimensional porous zinc anode (PF@Zn). Stable and flexible structure of the constructed fiber filament framework avoids direct contact of the aqueous electrolyte with the collector while relieving the stresses generated by dendrite growth. Moreover, when galvanizing or stripping, the zinc powder woven into the fiber network efficiently homogenizes the Zn2+ ion flux for a stable zinc cycle. Accordingly, the PF@Zn anode battery has a superior cycle life (240 h) and an increased Coulombic efficiency (99.1 %). An assembled C//PF@Zn capacitor has an impressive 96.6 % capacity retention after 3000 cycles. The study offers a scalable approach to modifying metal powder electrodes and transforming them into high-performance batteries.

PVDF composite fibers for wireless fall-alert detection

As the demand for healthcare devices continues to rise, novel technologies centered on personalized motion monitoring systems are being developed, wherein wearable sensors play a pivotal role. In the present investigation, an innovative wireless apparatus for detecting falls is introduced, which encompasses a specifically engineered pressure sensor composed of polyvinylidene fluoride (PVDF) composite fibers. Our design consists of high β-phase content of electrospun composites including 0.1 wt% of zinc oxide/reduced graphene oxide (ZnO/rGO) hybrid (mass ratio 90/10) which shows enhanced electrical voltage of 11.36 ± 0.72 V compared to pristine PVDF fiber. This piezoelectric pressure sensor is integrated with a wireless embedded system capable of transmitting an “SOS” message to a mobile phone upon the user’s fall experience. Such wearable fall alert detection systems with improved characteristics could benefit the elderly and patients requiring continuous monitoring for possible falls.

Development of multi-directional piezoelectric sensor doped with graphene by near-field electrospinning technology for calligraphy writing

A novel multi-directional (MD) circular-shaped fiber piezoelectric sensor was developed to detect calligraphy writing force from various directions quantitatively. The sensor was fabricated using polyvinylidene fluoride (PVDF) piezoelectric fibers doped with Graphene and spun using direct-write near-field electrospinning (NFES) technology. The NFES collector, designed as a rotating disc system, orderly collected the fibers to enhance the piezoelectric effect and dipole moments, forming the circular sensor. Flexible electrical electrodes with multiple signal output circuits were incorporated for calligraphy stroke sensing, bonded with circular PVDF fibers to create the flexible MD sensor. With inner and outer diameters of 20[Formula: see text]mm and 60[Formula: see text]mm, the circular sensor responded to deformable signals induced by calligraphy strokes. Parameters of sensor fabrication were optimized using the uniform design experimental method. Calibration involved tapping tests at 1–10[Formula: see text]Hz to correlate fiber output voltage with the corresponding force. The single sensor reached a maximum voltage output of approximately 908[Formula: see text]mV and detected forces ranging from 0.1 to 50[Formula: see text]N. After validating the MD circular-shaped piezoelectric sensor, a [Formula: see text] sensor array was configured for calligraphy writing force sensing, providing quantitative measurements of dynamic responses during writing, valuable as a data source for apprentice learning.

Highly durable platinum group metal-free catalyst fiber cathode MEAs for proton exchange membrane fuel cells

Fe-based platinum group metal (PGM)-free catalysts were incorporated into electrospun fiber mat or powder cathode membrane-electrode-assemblies (MEAs) with a Nafion 211 membrane and a Pt/C powder anode. Fabrication and characterization tests were performed on MEAs with: (1) a conventional powder cathode with a neat Nafion binder, (2) a fiber mat cathode with a Nafion/polyethylene oxide (PEO) binder, where PEO was extracted before MEA testing, (3) a powder cathode with a blended binder of Nafion and polyvinylidene fluoride (PVDF), and (4) a series of fiber mat cathodes with different Nafion/PVDF binder weight ratios. Cathode degradation occurred, with a loss in power output, in MEAs with a neat Nafion powder cathode or with a Nafion fiber cathode. In contrast, little or no power loss was observed for powder or fiber cathodes when the binder was a blend of Nafion and PVDF. The presence of hydrophobic PVDF drove water and electrogenerated peroxide out of the cathode, away from catalyst particles, which improved cathode durability, but PVDF also decreased the binder conductivity and slowed oxygen reduction kinetics, resulting in lower power densities. A 75:25 w:w Nafion:PVDF fiber cathode MEA was the best compromise for maximizing power and minimizing catalyst degradation. For such a cathode, with a PGM-free cathode catalyst loading of 3.0 mg cm−2, a power density of 88 mW cm−2 at 0.5 V, 80 °C, and 200 kPaabs pressure was maintained for 80 h of continuous operation.

Electrospun PVDF/Barium hexaferrite fiber composites for enhanced electromagnetic shielding in the X-band range

In the contemporary, digitally–driven era, the prevalence of electronic devices has drastically escalated electromagnetic (EM) pollution levels, marking a significant environmental challenge. Electrospun fiber composites of polyvinylidene fluoride (PVDF) and Barium hexaferrite (BHF) were analyzed for their potential usage in X-band electromagnetic shielding applications (EMSAs). Pure PVDF and BHF-PVDF fiber composite were manufactured by needleless electrospinning. X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), vibrating sample magnetometer (VSM), and EM measurements utilizing a vector network analyzer (VNA) are all used to describe the prepared samples. The XRD and FTIR analyses confirmed the successful incorporation of BHF into the PVDF matrix. The results show that adding PVDF to BHF in fiber form enhances the reflection loss (RL), indicating improved electromagnetic shielding effectiveness (EMSE). The SEM analysis revealed that the fiber composite had a uniform fiber diameter distribution. In contrast, the TGA analysis demonstrated good thermal stability of the fiber composite. Polymer samples were evaluated to enhance gamma radiation and neutron particle attenuation. MCNP5 and Phy-X/PSD software were used to study semi-crystalline fluorocarbon polymer (PVDF) and barium hex ferrite BaFe12O19 (30 wt%) with PVDF (70 wt%). The MCNP5 programme simulated 0.015–15 MeV radiation attenuation. Additionally, the Phy-X/PSD programme verified the simulated µ values for the chosen Mxenes materials. The MCNP-5 code and Phy-X/PSD results were agreed. The linear attenuation coefficients for the polymer samples ranged from 3.166 to 0.032 cm2.g−1 for PVDF and from 73.960 to 0.113 cm2.g−1 for PVDF and BHF-PVDF Fiber at photon energies from 0.015 to 15 MeV. Overall, the electrospun fiber composite of PVDF and BHF particles shows promise for EMSAs in the X-band range. The enhanced RL observed in our study suggests that these fiber composites could be used to protect against electromagnetic radiation (EMR) from electronic devices, which is increasingly concerning in today's modern society.

Optimizing Piezoelectric Coefficient in PVDF Fibers: Key Strategies for Energy Harvesting and Smart Textiles

AbstractWith the advancement in smart electronic devices and self‐powered devices, the demand for piezoelectric polymers has found potential research interest. Among these, electrospun polyvinylidene fluoride (PVDF) fibers have gained attention for energy harvesting due to their flexibility and higher piezoelectric coefficient. In the current work, various methods are compared to enhance PVDF's piezoelectric properties, including different solvents (DMAc, DMF), conductive filler (rGO), and annealing as post‐treatment. The results indicate that PVDF/rGO fibers in DMAc solvent exhibit the highest β phase fraction and crystallinity. Moreover, for the first time, the piezoelectric properties of PVDF/rGO electrospun single fiber is presented using high voltage switching spectroscopy piezoelectric force microscopy (HVSS‐PFM). The highest piezoelectric coefficient (d33) is measured for PVDF/DMAc‐rGO composite fibers. Notably, PVDF/rGO in DMAc solvent significantly improves the piezoelectric coefficient, leading to a remarkable fourfold increase in power density compared to pure PVDF, making it a promising material for energy harvesting applications.