Micromachines
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2021
·Vol. 12
·期 6
·602
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IF 2.891
Mingran Liu,Yang Liu,Limin Zhou
With the development of human healthcare devices, smart sensors, e-skins, and pressure sensors with outstanding sensitivity, flexibility, durability and biocompatibility have attracted more and more attention. In this paper, to develop a novel flexible pressure sensor with high sensitivity, different poly (vinylidene fluoride-trifluoroethylene) (PVDF-TrFE)-based composite membranes were fabricated, characterized and tested. To improve the β-phase crystallinity and piezoelectricity of the membranes, and for the purpose of comparison, nano ZnO particles with different concentrations (99:1, 9:1 in a weight ratio of PVDF-TrFE to ZnO) were, respectively added into PVDF-TrFE polymer acting as a nucleating agent and dielectric material. To facilitate the formation of β-phase crystal, the membranes were fabricated by electrospinning method. After the electrospinning, an annealing process was conducted to the fabricated membranes to increase the size and content of β-phase crystal. Then, the fabricated PVDF-TrFE membranes, acting as the core sensing layer, were, respectively built into multiple prototype sensors in a sandwich structure. The sensitivity of the prototype sensors was tested by an auto-clicker. The stimulation of the auto-clicker on the prototype sensors generated electrical signals, and the electrical signals were collected by a self-built testing platform powered by LabVIEW. As a result, combining the addition of ZnO nanofillers and the annealing process, a highly sensitive pressure sensor was fabricated. The optimal peak-to-peak voltage response generated from the prototype sensor was 1.788 V which shows a 75% increase compared to that of the pristine PVDF-TrFE sensor. Furthermore, a human pulse waveform was captured by a prototype sensor which exhibits tremendous prospects for application in healthcare devices.Keywords:PVDF-TrFE;PVDF-TrFE/ZnO;β phase crystal;human pulsation sensor
研究领域:
材料科学
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生物医学工程
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产品关联
DOI
PubMed
高影响因子
DESALINATION
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2014
·
IF 3.96
Wan-Zhong Lang,Xuan Zhang,Jian-Ping Shen,Hai-Peng Xu,Zhen-Liang Xu,Ya-Jun Guo
The impact of chemical treatment on the poly(vinylidene fluoride)/perfluorosulfonic acid (PVDF/PFSA) hollow fiber ultrafiltration membranes in acid, alkali and hypochlorite solutions was contrastively studied with PVDF/polyvinylpyrrolidone(PVP) ultrafiltration membranes. The morphologies, surface properties, permeation performances, antifouling ability and mechanical properties of the membranes were characterized by numerous state-of-the-art analytical techniques. The results reveal that the chemical treatment has less effect on the PVDF/PFSA membranes than on the PVDF/PVP membranes. After treating with alkali and hypochlorite solutions, the surface hydrophilicity of PVDF/PFSA membranes increases, while the surface hydrophilicity of PVDF/PVP membranes decreases. In comparison with the original membranes, the antifouling ability of the PVDF/PFSA membranes is improved, while the antifouling ability of the PVDF/PVP membranes declines. Compared with the chemically treated PVDF/PVP membranes, the treated PVDF/PFSA membranes are more easily regenerated after fouling. The chemical treatments lead to the decline of the mechanical strength in different degrees for both PVDF/PFSA and PVDF/PVP membranes. Nevertheless, this influence on PVDF/PFSA membranes is evidently less severe than on PVDF/PVP membranes.
研究领域:
材料科学
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环境工程
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产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2017
·
IF 3.387
Fengtao Chen,Xingxing Shi,Xiaobing Chen,Wenxing Chen
A facile strategy to improve the hydrophilicity and the antifouling properties of poly(vinylidene fluoride) (PVDF) membranes, a functional monomer of 4-methacrylamidobenzenesulfonic acid (MABS), was designed and synthesized through the amidation reaction between 2-methylacryloyl chloride and sulfanilic acid. Utilizing PVDF and the obtained MABS as reaction monomers, a novel amphiphilic copolymer was firstly prepared by radical polymerization method. The resulting PVDF-g-PMABS was used as a hydrophilic additive in the fabrication of PVDF porous membranes via immersion precipitation process. The surface chemical compositions and structure morphologies of as-prepared blend membranes (PVDF-g-PMABS/PVDF) were characterized by X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM), respectively. Contact angle measurement and cross-flow permeation test were employed to evaluate the hydrophilicity and antifouling properties of the membranes. It was found that the blend membrane with 4 wt.% PVDF-g-PMABS exhibited a noticeable pure water flux (136.34 L m −2 h −1 ) and a remarkable flux recovery ratio (FRR) of 98.60% in comparison with the pristine PVDF membrane (63.37 L m −2 h −1 and 38.67%, respectively). The enhanced performance was attributed to the synergetic effects of the strong hydrogen bonding force and the electrostatic repulsion of sulfonic groups against the protein foulants.
研究领域:
材料科学
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环境工程
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生物医学
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产品关联
DOI
高影响因子
Defence Technology
·
2024
·
IF 5
Zhanjun Yang,Hao Liu,Li Mi,Xiaoqian Wang,Oisik Das,Zhong xuan Han,Lin Jiang
To investigate the differences in combustion and energy release characteristics of metastable intermolecular composite materials composed of aluminum alloys and polyvinylidene fluoride (PVDF) with different compositions, two types of alloys were selected: Al-Mg and Al-Si. Pure aluminum powder of the same size was also chosen for comparison. The PVDF-coated metal particle composites and the mixtures of PVDF with metal particles were prepared using electrospray (ES) and physical blending methods (PM), respectively. A systematic study was conducted on the morphology, compositional structure, combustion performance, energy release characteristics, and thermal reactivity of the fabricated composites and their combustion products through scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), combustion performance experiments, closed vessel pressure tests, and simultaneous thermogravimetric-differential scanning calorimetry (TG-DSC). The experimental results indicated that the PVDF-coated metal particles prepared by the electrospray method exhibited a distinct core-shell structure, with the metal particles in close contact with the PVDF matrix. Compared to the PM blended materials, the ES composites demonstrated superior combustion performance and energy release characteristics during combustion. Analysis of different metal fuel systems under identical preparation conditions revealed that Al-Mg and Al-Si fuels modulate the combustion and energy release properties of aluminum alloy-PVDF MICs through two distinct pathways.
研究领域:
材料科学
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能源科学
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产品关联
DOI
高影响因子
Materials Research Express
·
2018
·Vol. 5
·期 10
·105506
·
IF 1.151
Zhao Yangzhou,Yuan Weifeng,Zhao Chaoyang,Gu Bin,Hu Ning
In this work, a fabrication process was developed to incorporate nano-SiO2 particles into poly(vinylidene fluoride) to make piezoelectric films. Experimental tests show that the piezoelectricity of the nanocomposites can be improved if the weight fraction of the additive increases within a specific range. Optical microscope images indicate that the presence of SiO2 particles can reduce the average diameter of the spherulites and increase the amount of heterogeneous nucleation sites in the PVDF matrix. In the fabrication process, stretching is used to enhance the α-β-phase transformation and orient the dipoles of the β-phase. From the experiment in which the nanocomposite films were affixed onto a vibrating beam for electricity harvesting, it was found that the output voltages of the films are dependent on not only the amplitude but also the frequency of the beam's vibration. This finding may have great potential in the field of energy harvesting using flexible piezoelectric films.
研究领域:
材料科学
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能源工程
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Yue Jia,Han Zhang,Huiyan Zhou,Yan Wang,Caiming Wang,Mengchen Yang,Chunxue Zhai,Xiaofei Qi,Dengwei Hu,Lili Zhao,Bin Cui
Flexible dielectrics play a crucial role in the advancement of capacitors. However, their limited energy storage density is an obstacle to both their application scope and miniaturization efforts. Inspired by an “egg effect”, this study introduces an innovative egg-like ceramic filler, namely Ba 0.34 Sr 0.51 Ca 0.15 Zr 0.1 Ti 0.9 O 3 -Y@Ba 0.34 Sr 0.51 Ca 0.15 Zr 0.1 Ti 0.9 O 3 -Mn@ZrO 2 (BSCZT-Y@BSCZT-Mn@ZrO 2 ), which is developed via a core–shell doping process. The separation of electrons and holes in the “egg yolk” (donor-rich core) and “egg white” (acceptor-rich shell) coupled with the current-limiting “eggshell” (wide bandgap oxide) in the ceramic fillers, resulting in a large effective polarization Δ P , a higher dielectric permittivity ε r , a lower tan δ , and a significant increase in the discharged energy storage density W rec of the composites. Together with the phase transition from α-PVDF to β-PVDF caused by the electrostatic interaction between fillers and PVDF, an ultra-high W rec of 33.2 J/cm 3 is achieved in the BSCZT-Y@BSCZT-Mn3@ZrO 2 /PVDF, which has the Δ P of 28.5 μC/cm 2 at 296.7 MV/m, along with ε r of 21.7 and tan δ of 0.018 at 1 kHz. Significantly, the composite film exhibits outstanding bending endurance. Even after 600 full bends, over 92 % of the capacitance retention rate can be retained. This research highlights the potential of ceramic filler structural design for flexible capacitors in low-power flexible electronics.
研究领域:
材料科学
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电气工程
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产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2020
·
IF 5.774
Chengcai Li,Xingyu Chen,Jie Luo,Feng Wang,Guojin Liu,Hailin Zhu,Yuhai Guo
A kind of PVDF composite membrane of good hydrophilic performance and antibacterial property was developed via an in-situ blending process. The PVDF-g-PGAL powder was prepared by degrading PVDF powder in alkaline condition, then oxidizing and grafting with Gallic acid (GAL). After mixing the original PVDF and PVDF-g-PGAL powder to prepare the PVDF composite membrane was soaked in NaHSO 3 to further improve its hydrophilicity. The oil-in-water emulsion separation efficiency of the composite membrane was regulated by varying the contents of the modified PVDF powder. When the content arrives at 30%, the composite membrane has the pore sizes in the range of 130.2–263.3 nm, the permeation flux of 2419.9L⋅m −2 ⋅h −1 ⋅bar −1 , the oil rejection rate of 97.39%, the flux recovery rate (FRR) of 94.59% and possesses the good anti-fouling performances during the cross-flow separation of the oil-in-water emulsion with the particle sizes within the scope of 10.1–396.1 nm. In addition, it has excellent antibacterial properties against E. coli and S. aureus, and effectively solves the blocking of membrane pores caused by the surface colonies in application. Therefore, the new composite PVDF membrane has the broad application prospects in the practical treatment of the complex oily wastewater media.
研究领域:
材料科学
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环境工程
·
生物医学
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
·
IF 8.6
Ruimin Zhu,Lucy Wang,Huayu Zhang,Chunjie Liu,Zhengbao Wang
ZIF-8 membranes have attracted extensive research attention due to their ease of synthesis, stable properties, and wide applicability. Compared to expensive inorganic supports, organic polymer supports are more flexible and inexpensive. However, addressing the issue of weak adhesion between the surface of the organic support and the ZIF-8 membrane layer poses a significant challenge. In this study, we present a strategy for preparation of ZIF-8 membrane by the fabrication of an asymmetric dual-layer polymeric hollow fiber support using polyvinylidene fluoride (PVDF) as the material. The outer layer of the support is composed of PVDF embedded with ZIF-8 seeds, while the inner layer consists of pure PVDF. This approach addresses the weak adhesion between the support and the ZIF-8 membrane layer formed through a one-step solvothermal crystallization process. The effects of ZIF-8 seed size, content, and crystallization conditions on the membrane structure and performance are investigated. Under the synergistic molecular sieving effects of ZIF-8 continuous membrane layer and ZIF-8 crystals within the outer layer of the support, larger gas molecules are difficult to penetrate the membrane layer, making the resulting membrane highly selective for the gas separation. Under the optimal fabrication conditions, the H 2 permeability of the ZIF-8 membrane is determined to be 1.52 ± 0.1 × 10 −7 mol·Pa −1 ·s −1 ·m −2 , with a H 2 /N 2 ideal separation selectivity of 69.5 ± 4. This method demonstrates simplicity and high reproducibility for preparation of ZIF-8 membranes on dual-layer hollow fibers, and it is expected to be extended to the growth and fabrication of other MOF membranes.
研究领域:
材料科学
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化学工程
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产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2025
·
IF 3.9
Chen Huyue,Li Yitao,Wang Jingrong,Lu Tengfei,Xu Haiping,Yang Dandan,Chen Lifei
As the demand for lightweight and compact integrated devices accelerates, dielectric materials are pivotal in enabling efficient energy storage. Composite materials, particularly those combining a polymer matrix with two-dimensional (2D) conductive MXene fillers, have emerged as promising candidates for improving dielectric performance. However, their high dielectric constant is often accompanied by significant dielectric loss, limiting their application in high-frequency circuits and electronic devices. This study investigates a ternary composite system consisting of polyvinylidene fluoride (PVDF) as the matrix, Ti 3 C 2 T x MXene as a conductive filler, and strontium titanate (SrTiO 3 ) as a ceramic filler to enhance dielectric properties. The ternary composites were prepared through a combination of physical mixing followed by a hot-pressing process. The results demonstrate that the MXene/SrTiO 3 /PVDF composites achieve a notable reduction in dielectric loss while retaining a high dielectric constant. At 12 wt% MXene, the composite achieves a dielectric constant of 117.8 at 10 3 Hz, 14.7 times higher than pure PVDF, with dielectric loss reduced by 71.4% compared to MXene/PVDF composites. Furthermore, the incorporation of SrTiO 3 markedly enhances the thermal stability, elevating the thermal decomposition temperature of the composite to 437.88 °C, up from 357.9 °C for pure PVDF. This research presents a promising strategy for developing capacitors with superior dielectric properties and enhanced thermal stability, suitable for high-temperature applications.
研究领域:
材料科学
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电子工程
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产品关联
DOI
高影响因子
MATERIALS LETTERS
·
2018
·
IF 2.687
Peng Qu,Xiaolin Liu,Sijing Wang,Chen Xiao,Shanshan Liu
Moderate dehydrofluorinated PVDF (MD PVDF) composed of polyene and untreated PVDF was produced by elimination reaction in polyvinyl pyrrolidone (PVP) and KOH aqueous solution. Dielectric films of MD PVDF were fabricated by solution casting method to study the energy density performance of the polymer. The energy density of MD PVDF was enhanced and the maximum energy density was 10.5 J/cm 3 at 450 kV/mm with an efficiency of 46%. The enhanced energy density was attributed to combined effects of high conductivity of polyene and charges blockage of untreated PVDF. This work may provide a new way to enhance the energy density performance of polymer dielectrics by moderate dehydrofluorination.
研究领域:
材料科学
·
能源存储
✓ 已验证
DOI
高影响因子
RSC Advances
·
2025
·Vol. 15
·期 15
·11503-11510
·
IF 4.6
Ping Li,Xiaolin Yue,Anhong Li,Can Cui,Lan Wang,Wenyuan Tan
Cobalt 2-methylimidazole (ZIF-67) has been broadly explored for its applications in the treatment of antibiotics in wastewater. However, ZIF-67 in powder form is difficult to recover. In the study, ZIF-67 and Polyvinylidene Fluoride (PVDF) were blended via electrospinning to prepare ZIF-67/PVDF membrane for adsorption of ciprofloxacin (CIP). The ZIF-67/PVDF membrane demonstrated outstanding adsorption efficiency for CIP, with a maximum adsorption capability of 4087.5 μg cm−2. The adsorption performance of ZIF-67/PVDF remains stable across a wide pH range and is unaffected by ionic interference. The ZIF-67/PVDF adsorbent follows pseudo-second-order kinetics and the Langmuir model. Furthermore, thermodynamic research indicates the adsorption of CIP is a spontaneous and exothermic process. It is proposed that the adsorption mechanism of CIP onto ZIF-67/PVDF involves electrostatic interactions, hydrogen bonding, π–π interactions, coordination bonding, and hydrophobic interactions.
研究领域:
环境科学
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材料科学
·
水处理技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Mohammed Karama Alsebaeai,Abdul Latif Ahmad,Boon Seng Ooi
In this research, the construction of a highly wetting-resistance membrane surface was achieved through an integrated dip-coating phase inversion process to accelerate water mass transfer of membrane distillation (MD). The synergistic effect of incorporating reduced graphene oxide (rGO) embedded Poly (vinylidene fluoride- co -hexafluoropropylene) (PVDF-HFP) on the surface of a PVDF hollow fiber support membrane using a dilute coating solution was studied. Various loadings of rGO nanosheets were incorporated into the dilute PVDF-HFP coating to systematically investigate its physicochemical characteristics, including surface morphology, hydrophobicity and wetting resistance which could be analyzed using scanning electron microscopy (SEM), atomic force microscopes (AFM), water contact angle (WCA), porosity measurement, pore size, x-ray diffraction (XRD), and liquid entry pressure (LEP) tests. The membrane separation performance for desalination was evaluated using direct contact membrane distillation (DCMD) process. Compared to the PVDF hollow fiber support membrane, the rGO-embedded PVDF-HFP coating layer demonstrates outstanding enhancements. The membrane surface exhibits enhanced hydrophobicity, as evidenced by an increased WCA from 105.37° (for the PVDF support membrane) to 148.37° (for the rGO/PVDF-HFP composite membrane). Additionally, the water permeability significantly improved, achieving a water flux of 25.9 kg m -2 h -1 (compared to 11.55 kg m -2 h -1 for the PVDF support membrane). These enhancements occur without compromising NaCl rejection, which remains consistently above 99.99 % (3.5 wt% NaCl aqueous solution at a feed temperature of 70 °C and a permeate temperature of 18 °C). These findings underscore the potential of rGO/PVDF-HFP in enhancing MD performance. The composite HF membrane demonstrates remarkable stability during continuous MD operation over a 48 h period. Pore wetting is effectively avoided, indicating that the composite membrane has superior resistance to wetting and excellent stability.
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）