Search Results (162)

The remediation of contaminants of emerging concern (CECs) requires innovative, high-efficiency, and sustainable technologies. Here, we investigate active polymeric membranes incorporating TiO₂/ZnO heterojunctions for synergistic sono-enhanced photocatalytic water treatment under both UV and visible-light irradiation. TiO₂/ZnO composites were synthesized and characterized, confirming the formation of type II heterojunctions with tailored optical properties for sunlight-driven photocatalysis. The catalysts were integrated into poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) and poly(vinylidene fluoride-co-trifluoroethylene) (PVDF-TrFE) matrixes using electrospinning (ES) and thermally induced phase separation (TIPS). ES membranes, specifically the ZnO-rich heterojunction within a PVDF-TrFE matrix (3T-7Z@TrFE ES), achieved the highest performance toward ciprofloxacin (CIP) degradation, reaching 71 and 57% under UV and visible light, respectively. The hybridization of the method by coupling ultrasound induced significant synergistic effects, with relative enhancement factors up to 1.38. Furthermore, the sono-enhanced photocatalytic pathway shifted the degradation mechanism towards the early fragmentation of the harmful piperazine ring, yielding a more sustainable degradation process. In addition, the composite membranes showed selective antibacterial activity against S. aureus, making this a multifunctional platform able not only to degrade CECs but also to mitigate membrane fouling. Overall, this work demonstrates the potential of tailored heterojunctions and composite membranes as sustainable platforms for the remediation of recalcitrant CECs in water, highlighting the synergy between photoactivity, piezoelectricity, and mechanistic control. Full article

Icing phenomena on wind turbine blades and components are a major problem, causing downtimes that increase maintenance costs, reducing the blade’s lifespan, or in severe cases, even leading to component damage. A nanofiber-based bi-layer liquid-infused surface (BLIS) coating was prepared and characterized, combining good adhesion to wind turbine blades with low ice adhesion. The BLIS coating was produced by a new method combining electrospinning and a heat treatment step, containing a poly ethyl-2-cyanoacrylate (PECA)-based adhesive layer, a slippery layer of poly vinylidene fluoride-co-hexafluoropropylene (PVDF-HFP) copolymer, and an infiltrated perfluoropolyether lubricant. Thermogravimetric analysis (TGA) was used to ensure the thermal stability of the polymers in the nanofiber coating layers and to optimize the heat treatment process of the layers. Microstructural changes were studied by scanning electron microscopy (SEM) and surface roughness measurements. Contact angle measurements and sliding velocity tests on wind turbine blade segments at icing conditions of 0 °C and +5 °C indicate that the water sliding properties of the BLIS coating were improved compared to uncoated blades. In addition, coated blade segments showed a 50% lower ice adhesion strength than uncoated blades. Full article

Liquid electrolytes in conventional lithium-ion batteries pose safety risks associated with flammability, leakage, and explosion, whereas solid polymer electrolytes are generally limited by insufficient ionic conductivity at ambient temperature, restricting the development of high-energy lithium batteries. To address these issues, flexible poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP)-based gel polymer electrolyte membranes (GPEs) were prepared via a slit-coating process combined with UV curing. NASICON-type lithium aluminum titanium phosphate (Li_1.3Al_0.3Ti_1.7P₃O₁₂, LATP) and garnet-type tantalum-doped lithium lanthanum zirconate (Li_6.4La₃Zr_1.4Ta_0.6O₁₂, LLZTO) were introduced as inorganic ceramic fillers to improve the ion-transport and interfacial properties of the GPE. Among the investigated samples, the PVDF-HFP-based GPE containing 10 wt% LLZTO exhibited the best overall performance, with an ionic conductivity of 3.40 × 10⁻⁴ S·cm⁻¹ at ambient temperature and a Li⁺ transference number of 0.77. Cyclic voltammetry results showed that the LLZTO-modified electrolyte membrane exhibited sharper and more symmetric redox peaks, higher peak current response, and better curve overlap during repeated cycles, indicating improved electrochemical reversibility and interfacial stability. In addition, LLZTO incorporation enhanced the mechanical strength, broadened the electrochemical stability window, and improved the flame-retardant behavior of the membrane. The LiFePO₄/GPE/Li cell assembled with the optimized membrane delivered an initial discharge capacity of 160 mAh·g⁻¹ at 0.1 C and maintained 80 mAh·g⁻¹ at 1 C, demonstrating good rate capability. Moreover, a capacity retention of 96% was maintained after 100 cycles at 0.1 C, confirming excellent cycling stability. Therefore, this work provides an effective strategy for the structural optimization and scalable preparation of high-performance gel polymer electrolyte membranes for lithium battery applications. Full article

Polybenzimidazole (PBI) is a promising separator for lithium-ion batteries (LIBs) owing to its excellent thermal/chemical stability and mechanical strength, but its application is limited by poor solubility and processability. Herein, a novel ether-functionalized PBI was synthesized, and three-layer composite separators (PBIPHPE) were fabricated by electrospinning PBI/PVDF-HFP blends onto polyethylene (PE) substrate. The PBIPHPE separator exhibits high porosity (73.1%), superior electrolyte uptake (211.2%), and excellent ionic conductivity (1.125 mS/cm), with no dimensional change after thermal treatment at 150 °C for 0.5 h. Lithium-ion batteries assembled with PBIPHPE deliver an initial specific capacity of 157.7 mAh/g, retain 86.0% capacity after 400 cycles at 2 C, and show only 15.7% capacity decay from 0.2 C to 5 C. Molecular dynamics simulations of the composite separator–electrolyte system were performed to reveal Li⁺ transport behaviors. The results confirm that ether-functionalized PBIPHPEs enhance Li⁺ transport and cycling stability, providing a promising route for high-performance separators. Full article

In this study, poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) films embedded with silver nanoparticles were fabricated to investigate their antibacterial performance against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Inspired by the nanoscale topographies of natural antibacterial surfaces, such as dragonfly and cicada wings, microstructured pillars were introduced onto the polymer surface to enhance its bactericidal activity by increasing the effective contact area. Surface morphology was characterised using scanning electron microscopy (SEM), including higher-magnification imaging of micropillar surfaces, while energy-dispersive X-ray spectroscopy confirmed the presence of silver. Higher-magnification SEM revealed nanoscale surface features on the micropillars, attributed to embedded or surface-associated silver nanoparticles. Antibacterial performance was evaluated using confocal laser scanning microscopy with live/dead staining. The PVDF-HFP/Ag films exhibited a significant reduction in bacterial viability, particularly against S. aureus (reducing viability to 0.6% ± 1.1%), while showing moderate activity against E. coli (41.0% ± 3.7% viability). While the fabricated micropillars (~5 µm) are larger than bacterial cells and unlikely to induce direct mechanical rupture, they increase surface interaction. To further investigate the theoretical antibacterial mechanism of scaled-down features, finite element analysis (FEA) was performed to model the mechanical interaction between bacterial cells and nanostructured pillars. The simulation results indicated localised stress concentrations that could compromise bacterial membrane integrity, suggesting a possible mechanobactericidal contribution if the microstructures are further reduced to the nanoscale, in addition to the primary biochemical effects of silver nanoparticles. FEA results do not aim to explain the experimentally observed antibacterial performance and should be interpreted only as a conceptual investigation. These findings demonstrate the potential of bio-inspired PVDF-HFP/Ag films as antibacterial materials for food packaging and related applications, subject to future comprehensive toxicity and quantitative microbiological evaluations. Full article

Efficient, low-cost catalysts are required for on-demand H₂ generation from chemical hydrides. This study utilized piezoelectric poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) nanofibers (NFs) as a support to encapsulate bimetallic Co–Mo nanoparticles (NPs) for H₂ production via sodium borohydride (SBH) methanolysis. The PVDF-HFP membranes were synthesized through electrospinning, followed by in situ SBH reduction, which resulted in the uniform dispersion of amorphous Co–Mo NPs within the nanofibrous matrix. The optimized CoMo-0.2@PVDF-HFP membrane exhibited a hydrogen generation rate (HGR) of 1.9 × 10³ mL·min⁻¹·g⁻¹ (Co) at 298 K, indicating a 3.6-fold improvement relative to monometallic Co. Kinetic studies showed a nearly first-order relationship with catalyst dose and a nearly zero-order relationship with respect to SBH concentration, suggesting kinetics controlled by surface saturation. The activation energy (E_a) was determined to be 14.03 kJ·mol⁻¹. Moreover, the catalyst maintained over 80% of its original activity after five cycles. This enhanced performance is attributed to the combined effects of Co and Mo, the amorphous nature of the active sites, and the piezoelectric polarization of PVDF-HFP during mechanical stirring, which together improve charge transfer and reduce NP agglomeration. Full article

Polymer inclusion membranes (PIMs) based on PVDF-HFP as the base polymer and Aliquat 336 as the carrier in a mass ratio of 6:4 with concentrations of embedded glass fibers up to 5 wt% were successfully fabricated. Their microstructure, as well as their mechanical and thermal properties, were characterized using scanning electron microscopy (SEM), small-angle X-ray scattering (SAXS), differential thermal analysis/thermogravimetric analysis (DTA/TGA), and tensile testing. Membrane performance and long-term stability in transporting thiocyanate ions were evaluated in a two-compartment transport cell. The results showed that the membranes retained their amorphous structure even with glass-fiber loadings of up to 5 wt%. The addition of glass fibers was found to primarily enhance the elastic modulus and tensile strength, while causing a moderate reduction in plasticity without negatively affecting membrane transport properties and long-term stability. Therefore, it was concluded that the incorporation of glass fibers could improve the suitability of PIMs for industrial applications. Full article

Poly(vinylidene fluoride) (PVDF)-based ultrafiltration membranes play key roles in aqueous separation fields. However, the inherent hydrophobicity of PVDF always generates higher water permeation resistance and a greater fouling tendency in the filtration process. Different to the widely reported and widely used blending methods of increasing the hydrophilicity of PVDF membranes, the mass-produced hydrophilic PVDF copolymer is expected to be more efficient in producing high performance membranes. For this purpose, the present research offers a new and scalable approach to improving the hydrophilic properties of PVDF-based membranes through amphiphilic copolymers. Using 2-trifluoromethylacrylic acid (MAF) and hexafluoropropylene (HFP), carboxylated PVDF (PVHM) was synthesized following simple radical suspension copolymerization. Via a non-solvent-induced phase separation (NIPS) method, PVHM membranes were prepared and characterized. It was found that the PVHM membranes had enhanced hydrophilicity, permeability, fouling resistance, and alkali resistance compared with PVDF membranes. For the PVHM containing 8.3 wt% MAF, its membrane demonstrated superior static/dynamic fouling resistance to sodium alginate (FRR up to 99.1% for SA). Therefore, carboxylated PVDF polymers show potential for use in the industrial production of high-performance ultrafiltration membranes. Full article

Electrochromic devices have emerged as promising candidates for non-emissive displays due to their particular photoelectric performance in complex lighting environments. They exhibit considerable potential in emerging fields such as Internet of Things terminals, flexible wearables and human–computer interaction interfaces. In this study, we developed a low-power electrochromic display based on a Pt/FTO (Fluorine doped tin oxide) electrocatalytic counter electrode and a Poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) porous gel electrolyte. The Pt catalyst enhances Br⁻/Br³⁻ redox reactivity, which reduces the driving voltage from 2 V to 1 V, and accelerates the electrode reaction kinetics. It is systematically explained by the Density Functional Theory (DFT) calculations and electrochemical characterization. Furthermore, we demonstrate a proof-of-concept multicolor display incorporating the electrocatalytic counter electrode with various viologen derivatives. This approach provides a significant advancement toward next-generation high-performance displays and is supportive of the development of energy-efficient optoelectronic devices. Full article

Gel polymer electrolytes (GPEs) typically suffer from sluggish kinetics and interfacial instability at elevated temperatures and high voltages. Herein, 3-(trifluoromethyl)-1H-1,2,4-triazole (TTA) is employed to construct an ultrathin (~25 μm), robust, and homogeneous GPE. TTA acts as a molecular bridge, significantly improving compatibility between the PVDF-HFP (Poly(vinylidene fluoride-co-hexafluoropropylene)) matrix and LLZTO (Li_6.4La₃Zr_1.4Ta_0.6O₁₂) fillers to create continuous ion-conducting pathways. Consequently, the TTA-GPEs exhibits high ionic conductivity (0.267 mS cm⁻¹ at room temperature), low activation energy (0.181 eV), and an increased lithium-ion transference number (0.425). Advanced surface analysis reveals that TTA preferentially reacts to form a dense, gradient hierarchical interphase (solid electrolyte interphase/cathode electrolyte interphase, SEI/CEI) enriched with inorganic species (LiF, Li₃N, and Li₂S) on the inner side. This architecture suppresses parasitic reactions and lithium dendrite growth. Accordingly, NCM811(LiNi_0.8Co_0.1Mn_0.1O₂)//Li batteries with TTA-GPEs demonstrate stable cycling at 80 °C and 1C, retaining 57.68% capacity after 125 cycles—significantly outperforming benchmarks. This study offers a molecular engineering strategy to simultaneously optimize bulk transport and interfacial stability for high-energy-density solid-state batteries. Full article

Naturally occurring halloysite nanotubes (HNTs), a clay mineral characterized by a unique dual-charge architecture, offer a promising strategy for enhancing the performance of composite polymer electrolyte (CPE). In this work, HNTs are introduced as a low-cost, functional filler to simultaneously address two key limitations of poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP)-based CPE: low ionic conductivity and inadequate lithium-ion transference number. The negatively charged outer surface of HNTs facilitates Li⁺ transport, while the positively charged inner lumen confines anions such as TFSI⁻. Controlled acid etching (6 M HCl, 12 h) further optimizes this structure by removing surface impurities and enlarging the lumen, thereby enhancing both charge-directed ion transport pathways. The resulting HNT-modified CPE achieves a high ionic conductivity of 6.1 × 10⁻⁴ S⋅cm⁻¹ and a Li⁺ transference number of 0.73. When assembled into Li||CPE||LiFePO₄ cells, the electrolyte enables stable cycling over 300 cycles at 0.2C, retains 119.2 mAh/g at 2C, and delivers 85.7 mAh/g even at 5C, demonstrating excellent cycling stability and rate capability. This study reveals the potential of mineral-derived nanomaterials, with their inherent structural and physicochemical properties, to serve as key functional components in high-performance batteries. Full article

In this work, biodegradable poly(vinyl alcohol) (PVA) and ferroelectric poly(vinylidene fluoride-co-hexafluoropropylene) (P(VDF-HFP)) nanofibers were successfully fabricated via co-electrospinning. The morphology and microstructure of co-electrospun PVA/P(VDF-HFP) nanofibers were analyzed, demonstrating that P(VDF-HFP) incorporation significantly affected fiber diameter and phase distribution. These structural features altered the fiber diameter and surface area of the co-electrospun system, thereby affecting interfacial polarization and the resulting dielectric and energy storage performance. As a result, the dielectric constant of the PVA/P(VDF-HFP) nanofibers (M1) was enhanced by up to 1.8 times compared with pure PVA nanofibers (M0), owing to interfacial polarization arising from increased surface charge accumulation at the PVA/P(VDF-HFP) interfaces. Meanwhile, dielectric loss and electrical conductivity were effectively controlled, indicating improved electrical stability of the co-electrospun system. Furthermore, ferroelectric and energy storage analyses revealed that appropriate incorporation of P(VDF-HFP) and phase distribution significantly enhanced polarization and energy storage performance. The energy storage density increased from 0.83 to 3.21 mJ cm⁻³ at 20 MV m⁻¹, corresponding to an improvement of 287% while maintaining a high energy efficiency of approximately 90%. Owing to their favorable dielectric properties, mechanical flexibility, and environmental compatibility, the co-electrospun PVA/P(VDF-HFP) nanofibers demonstrate great potential for low-field wearable and biomedical energy storage devices. Full article

The stability of the electrolyte is very important for the development of high-performance all-solid-state lithium batteries. To improve the stability of electrolyte performance, it is essential to first understand the causes of its deterioration. Physically speaking, the degradation of electrolyte performance is mainly due to interface degradation. PAN-PVDF-HFP-LiClO₄-Li₆.₄La₃Zr₁.₄Ta₀.₆O₁₂ (LLZTO) gel polymer electrolyte was prepared by the UV curing method and assembled into a solid-state battery. The electrochemical properties of solid-state batteries were tested at −20 °C, 30 °C, and 60 °C. The test results show that the gel polymer electrolyte exhibits good electrochemical performance in this temperature range. (The ionic conductivities of the gel polymer electrolyte at −20 °C and 60 °C were 3.95 × 10⁻⁴ S·cm⁻¹ and 5.04 × 10⁻⁴ S·cm⁻¹, respectively.) At a current density of 0.2 C, the battery exhibited high initial specific discharge capacities of 122 mAh g⁻¹ and 151.6 mAh g⁻¹ at −20 °C and 60 °C. The gel polymer electrolyte before and after working at different temperatures was characterized, and the ion transport was analyzed to explore the physical reasons for the degradation of the gel polymer electrolyte membrane interface. Therefore, this work provides a certain theoretical basis for improving the stability of solid-state lithium-ion batteries. Full article

Multifiber polyvinylidene fluoride (PVDF), a thermoplastic polymer, was produced as a one-dimensional nanostructure via the electrospinning technique. Due to the peculiar properties attributed to the nanoscale fiber dimension, PVDF material, as pure, and with the addition of hexafluoropropylene (HFP) and/or graphene oxide (GO), was thoroughly characterized in terms of morphology, density, optical and electrical properties, surface wettability, mechanical resistance, and other physical characteristics. PVDF, with a multifiber surface, with or without the addition of other elements, has been demonstrated to have a strong capacity to absorb high concentrations of gases, water, nanoparticles, and other substances. The material’s dielectric behavior and soft and shock-absorbing polymer properties make it ideal for biocompatible applications, which will be showcased and discussed in this work. A detailed comparison was made between bulk PVDF, multifiber PVDF, and PVDF containing HFP and/or GO, highlighting the changes in polymer properties. Full article

With the increasing demand for high-energy-density lithium batteries, the role of separators has expanded significantly beyond conventional ion conduction and physical isolation. By integrating sensors and introducing functional coatings, separators have gained the ability to monitor internal states in real time and achieve adaptive regulation. This paper systematically reviews the latest research progress on separators modified with functional materials and coatings to achieve information sensing, intelligent response, and multifunctional integration. Notably, an electrochemical sensor based on MXene/MWCNTs-COOH/MOF-808 has been developed for rapid chemical detection; a fully printed ultra-thin flexible multifunctional sensor array has enabled multi-parameter synchronous monitoring; an ion-selective MOF-808-EDTA separator has induced uniform lithium-ion flux; and a PVDF-HFP/LLZTO/PVDF-HFP trilayer separator has maintained structural integrity at 300 °C. These innovative achievements fully demonstrate the enormous potential of intelligent separators in monitoring internal battery states, inhibiting dendrite growth, preventing thermal runaway, and significantly enhancing battery safety, cycle life, and energy density. This points to a transformative development path for the next generation of batteries with higher safety and intelligence. Full article