POLYMER
·
2018
·
IF 3.483
Hongde Lei,Lu Liu,Lukuan Huang,Weixing Li,Weihong Xing
In this study, we fabricated a novel anti-fouling poly(vinylidene fluoride) (PVDF) membrane using a novel amphiphilic copolymer of PVDF grafted with tetrahydrofurfuryl methacrylate (PVDF-g-THFMA). This copolymer was synthesized via photoinduced Cu(II)-mediated reversible deactivation radical polymerization . The amphiphilic copolymer was characterized by 1 H nuclear magnetic resonance and Fourier transform infrared spectroscopy . The morphology of the copolymer was examined using scanning electron microscopy. The permeability and hydrophilicity of the membranes were evaluated on the basis of their pure water flux and dynamic contact angles, respectively. The anti-fouling property of the membranes was evaluated by carrying out filtration using a bovine serum albumin (BSA) solution. The PVDF-g-THFMA copolymer membranes showed a pure flux of up to 293.9 L m −2 h −1 bar −1 and a molecular weight cut off of 39.5 kDa. After the filtration of the BSA solution, the PVDF-g-THFMA copolymer membrane was washed with deionized water and the recovery ratio of the pure water flux reached a value of 89.1%. The modified membrane showed good filtration performance and anti-fouling property.
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高影响因子
COLLOID AND POLYMER SCIENCE
·
2013
·Vol. 291
·期 7
·1573-1580
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IF 2.161
Zhao Xuejuan,Zhang Jun,Chen Shuangjun,Wang Xiaolin,Wang Jianxin
The in situ polymerization of poly(ethylene glycol) methyl ether methacrylate (PEGMA) in poly(vinylidene fluoride) (PVDF) solution was carried out to prepare hydrophilic PVDF/PPEGMA blends. Based on T
g data, the system displayed some miscibility at low PPEGMA content because there were some interactions between PVDF and PPEGMA, as illustrated by Fourier transform infrared spectroscopy analysis, while the miscibility disappeared at high PPEGMA content. The β phase was the predominant crystalline phase of PVDF in the in situ blends, which was independent on PPEGMA content. However, the addition of PPEGMA could change the unit cell structure in the direction of the a -axis of β phase. The degree of crystallinity of the in situ blends calculated by wide-angle X-ray diffraction and differential scanning calorimetry displayed different tendencies with PPEGMA content. The scanning electron microscopy showed that the “spherulites” size increased with the increase in PPEGMA content, since the “spherulites” were comprised of not only crystalline PVDF but also amorphous PVDF and PPEGMA. In addition, the in situ blend had a great improvement in the hydrophilicity; specifically, its water contact angle was down to 26° when the PPEGMA content only increased to 26.9 wt.%.
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FIBERS AND POLYMERS
·
2015
·Vol. 16
·期 10
·2130-2134
·
IF 0.881
Chen Yingbo,Wang Biao,Zhang Shifeng,Hu Xiaoyu,Cheng Bowen,Liu Dongqing,Zhang Yufeng
Cu-BTC/PVDF composite membranes were prepared by immersing PVDF hollow fiber supporting membranes into copper acetate aqueous solution and trimesic acid ethanol solution repeatedly. Surface and cross sectional morphologies of Cu-BTC crystals on the supporting PVDF membrane were investigated using SEM. Chemical composition and crystal structure of Cu-BTC were characterized by IR and XRD. Gas permeance and separation factor for CO 2 and N 2 of the Cu- BTC/PVDF composite membrane were recorded under different pressures. The results illustrated that with increasing reaction times, the crystal layer became more in density and less in defects, resulting in decrease of gas permeance and the separation mechanism changing from convective flow to Knusen diffusion.
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Desalination and Water Treatment
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2024
·
IF 1
Shuyi Chen,Noor Khatoon,Chen Zhang,Qi Zhang,Shuhong Jiang,Honghai Yang,Jun Wang
Selective recovery of recyclables is a major challenge when treating textile wastewater. For this reason, there is an urgent need to develop nanofiltration membranes with high permeability and selective filtration. In response, a novel composite PVDF loose nanofiltration membrane was developed by combining two different mixed amines system/dopamine (DA) followed by interfacial polymerization with benzoyl chloride (TMC). The two different amines systems were a mixture of GAZ and PEI and a mixture of PIP and PEI, respectively. The effects of GAZ/PEI and PIP/PEI on the microstructure was characterized by SEM, AFM, FTIR and XPS and performance of the membrane was also investigated. The effects of GAZ/PEI and PIP/PEI on the microstructure and the selective layer of membranes were different. The results stated that with the increase of GAZ/PEI the thickness of the selective layer, surface roughness decreased, while the fluxes of pure water and dye wastewater increased. However, with increasing PIP/PEI, surface nodules and roughness both increased. Contrarily, the thickness of the selective layer and PEG800 rejection first decreased and then increased, while the flux of pure water and the dye wastewater first increased and then decreased. The optimal GAZ/PEI and PIP/PEI were 9/91 and 50/50, respectively. When the GAZ/PEI was 9/91, the pure water flux and the RB5 wastewater flux were 20.7 L∙(m 2 ∙h) −1 and 11.5 L∙(m 2 ∙h) −1 . The dye (RB5) retention rate was 94.3% and salt retention rate was 2.1%. However, when the PIP/PEI was 50/50, the pure water flux and RB5 wastewater flux were 26.6 L∙(m 2 ∙h) −1 and 17.1 L∙(m 2 ∙h) −1 increased by 87.3% and 134.2% respectively. The retention rates of RB5 and NaCl were 96.3% and 1.7%. The above results indicate that the composite PVDF LNF membranes prepared with mixed amine monomers instead of single amine monomers have good selective filtration performance.
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Surfaces and Interfaces
·
2024
·
IF 5.7
Xiaojia Zhao,Junjie Fu,Fangqian Yin,Chaoqun Li,Yuyang Xu,Guirong Peng
A one-step co-deposition method based on dopamine and hydrophilic hydroxyethyl methacrylate (HEMA) was proposed for the modification of polyvinylidene fluoride (PVDF) membrane, which could ameliorate its oil-water separation performances and hydrophilicity. A range of modified membranes were prepared by adding different content of HEMA in the reaction solution. For the improved membrane, the minimum water contact angle can reach 13.63°, and the maximum underwater oil contact angle can reach about 150°. The pure water flux for the improved membrane reaches 9668 L·m -2 ·h -1 ·bar -1 , showing excellent hydrophilicity. In addition, the separation efficiency of the improved membrane for a variety of oil-water emulsions exceeds 98%, indicating good permeability and circulating oil resistance. At the same time, this approach is also applicable to other membranes on account of the extensive availability of dopamine.
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Nanoscale
·
2024
·
IF 5.8
Haitao Li,Yingying Zhang,Han Dai,Veronica Pereir,Junfeng Zhao,Hiang Kwee Lee
Polyvinylidene fluoride (PVDF)-based piezoelectric catalysts show promise in mechanical force-driven catalysis due to their good biocompatibility, flexibility, and ease of fabrication. However, the catalytic activity of pristine PVDF is limited due to its low piezoelectric phase content (<20%), poor orientation, and low surface carrier concentration. Here, we introduce an efficient PVDF-based composite nano-catalyst (rGO/PVDF) with high piezoelectric catalytic performance. We achieve this by employing a composite strategy that combines nanoscale water-induced polarization with polar functional group-modified graphene (rGO) serving as a nanoelectrode. The nanoscale water polarization effect, together with the two-dimensional planar structure of PVDF and the modified graphene's polar functional groups, effectively induces orientation in the PVDF piezoelectric phase to increase the functional β phase content. As a result, the β phase content and crystallinity of rGO/PVDF reach 95% and 40%, respectively, which are 600% and 170% higher compared to those of pristine PVDF. This enhancement plays a crucial role in endowing the material with strong force-to-electricity conversion characteristics. Additionally, the surface-modified rGO also boosts PVDF's surface carrier concentration and provides active sites for catalysis on the rGO/PVDF composite. Notably, under optimized conditions, our catalyst achieves a ∼99.1% degradation rate of organic pollutants (10 mg L−1) after 12 minutes of sonication at 240 W and maintains a high efficiency of ∼93.7% even at a 10 times higher pollutant concentration (100 mg L−1). Our piezoelectric catalyst also demonstrates efficient H2O2 production at 95.8 mmol grGO−1 h−1, which is ∼9-fold and ∼134-fold higher than those of untreated PVDF and previously reported PVDF-based piezoelectric catalysts, respectively. This work paves the way for the development of highly efficient PVDF-based piezoelectric catalysts, thereby offering valuable insights for the advancement of mechanically driven catalysis in the environmental, energy, and chemical sectors.
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PubMed
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2024
·
IF 8.4
Jinli Zhao,Juan Li,Qingbai Chen,Mengwei Yang,Yongkang Li,Hong Li,Yuzhong Zhang,Jianyou Wang
The influence of crystallization behavior on membrane structure and performance has been extensively studied in many membrane fields. Some studies of proton exchange membranes used in fuel cells have involved the influence of crystallization. However, crystallization of ion exchange membranes (IEMs) used in electrodialysis (ED) has been rarely studied. Co-ion leakage in ED process is adverse, but there have been few mechanism studies regarding how co-ions cross IEM surfaces on the concentration chamber side and migrate into the dilution chamber to reduce current efficiency. Polyvinylidene fluoride is a kind of good crystalline material. In this study, sodium dodecyl benzene sulfonate was introduced as the functional material , with polyvinylpyrrolidone (PVP) as the hydrophilizing agent. They were blended to prepare cation exchange membranes (CEMs). Amorphous PVP was used to regulate membrane crystallization behavior. The results showed that, when the ion exchange capacity is basically equal, surface roughness of the prepared crystalline CEMs was low and the structure dense. The ED efficiency significantly surpassed amorphous CEMs. The co-ion leakage of amorphous CEMs was greater than those of crystalline CEMs due to the rough and non-dense surfaces of amorphous CEMs. However, after densification modification, although surface resistance increased, co-ion leakage was effectively suppressed. Combining simulation and theoretical analysis, it was presumed that dense membrane surfaces on the concentrated chamber side was very important for suppressing co-ion leakage. This study on the influence and mechanism of crystallinity and co-ion leakage was helpful for optimizing CEM mass transfer and improving current efficiency.
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SEPARATION AND PURIFICATION TECHNOLOGY
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2024
·
IF 8.1
Shangheng Jiang,Shiqiang Liang,Chunxiao Hu,Yuanfang Fan,Zhongmin Su,Zhi Geng,Chi Wang
Membrane Distillation (MD) technology stands out for its cost-effectiveness and sustainability in diverse applications, such as high-salinity wastewater treatment and seawater desalination. However, conventional MD membranes frequently encounter challenges associated with inadequate permeate flux and insufficient anti-wetting performance. In the present study, we fabricated a series of ZIF-CoZn@PVDF-HFP composite nanofiber membranes with a core–shell structure via coaxial electrospinning. Here, PVDF-HFP functions as the core, while a blend of bimetallic Zeolitic imidazolate framework ZIF-CoZn nanoparticles and PVDF-HFP constitutes the shell. Through the utilization of the coaxial technology, functional nanoparticles achieve uniform and stably dispersed on the nanofiber surface, leading to the creation of a secondary rough structure in addition to the inherent roughness of single-nozzle electrospinning. This results in a surface with a 3D-hierarchical structure. The significantly amplifies the evaporation area on the surface of the composite nanofiber membrane, thereby bolstering the permeate flux in the MD process. Additionally, the incorporation of bimetallic ZIF-CoZn nanoparticles, recognized for their superior hydrophobicity and low thermal conductivity, improves the anti-wetting and heat-insulating properties of the composite nanofiber membrane, further advancing permeate flux performance. Using a 35 g L −1 NaCl as the feed solution, the optimal 1 % ZIF-CoZn@PVDF-HFP composite nanofiber membrane demonstrated a permeate flux of 21.8 L m −2 h −1 , coupled with a salt rejection rate exceeding 99.9 %. Even during long-term MD testing, it maintained excellent insulation and anti-wetting capabilities. Our research offers a convenient and effective approach for fabricating anti-wetting composite nanofiber membranes.
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Materials Today Chemistry
·
2025
·
IF 6.7
Kai Zhang,Wenying Zhou,Na Lin,Chenyu Li,Jinming Fan,Jiahuan Zhao,Yuan Jia,Mengxue Yuan
With the wide applications of polymer dielectrics in electronic devices and power supply systems, it is of great importance to explore polymeric composites with simultaneously high dielectric permittivity ( ε ) along with low loss ( tan δ ), and large breakdown strength ( E b ). To concurrently achieve these superior qualities in silicon (Si)/poly(vinylidene fluoride) (PVDF), in this study, a sol-gel method was used to decorate raw Si with a layer of titanium oxide (TiO 2 ), which was then incorporated into PVDF to produce a series of Si@TiO 2 /PVDF composites with diverse TiO 2 shell thicknesses. The findings demonstrate that compared with pristine Si/PVDF both loss and leakage conductivity of Si@TiO 2 /PVDF are markedly decreased by the TiO 2 shell, which enhances the interfacial compatibility between Si and PVDF, and blocks the creation of conductive network from virgin Si particles, inhibiting the long-range migration of carriers. Furthermore, the TiO 2 interlayer not only induces traps and increases the energy barrier height for trapped charges to de-trap, but also mitigates the intense interfacial dielectric mismatch subsequently lifting the E b . The theoretic fitting results via Havriliak-Negami equation demonstrate the TiO 2 shell’ suppression on charge migration and reveal the underlying polarization mechanism. Fine assembly of TiO 2 with desirable thickness onto Si realizes effective regulation of over dielectric parameters of the composites. The developed Si@TiO 2 /PVDF present concurrently high ε , E b but low loss characteristics, indicating promising potential applications in advanced electronic devices and power systems.
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高影响因子
COMPOSITES COMMUNICATIONS
·
2024
·
IF 6.5
Arif Hussain,Liu Jie,Can Zhao,Junyi Yu,Asad Muhammad Khan,Suibin Luo,Shuhui Yu
Polymer-based flexible materials can be slated as successors of conventional inorganic ferroelectrics to induce tunable dielectric properties in microwave devices because of their advantageous characteristics, such as lightweight, flexibility, easy processibility, and eco-friendliness. Ferroelectric polymers require a high external field to induce dielectric tunability, which can be a problem. Another problem is the dielectric mismatch and incompatibility between ceramic and polymer, which hinders the ceramic-polymer composites to induce tunable dielectric properties. Herin, titanium oxide-barium strontium titanate (TO@BST) core-shell nanoparticle are reinforced into the poly (vinylidene fluoride) (PVDF) matrix to fabricate flexible nanocomposite with tunable dielectric properties. The core-shell nanoparticle-based nanocomposite produced low voltage dielectric tunability (12.03 % at 33 kV/mm) and excellent tunable dielectric efficiency ( T uE , 0.8 %) while maintaining low dielectric loss (tanδ, 0.024). Moreover, TO@BST-based nanocomposite exhibited a remarkable 91 % improvement in dielectric constant compared to pure PVDF and a 25.7 % improvement compared to BST-based nanocomposite. The dielectric breakdown strength ( E b ) of the nanocomposite filled with 40 wt% TO@BST nanoparticle improved by 45 % (114.36 kV/mm) compared to pure BST-based nanocomposite (78.68 kV/mm). This work provides valuable insights into designing novel flexible nanocomposites with low voltage tunability and high breakdown strength at high filler loading.
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International Journal of Nanomedicine
·
2025
·
IF 6.5
Tiantian Liu,Feifei Xie,Lele Geng,Ruizhe He,Mengzhe Sun,Tao Ni,Peng Xu,Chao Xing,Yinbo Peng,Ke Chen,Yong Fang
Purpose The purpose of this study is to develop an innovative solution for chronic wounds in high-mobility areas, such as joints, where conventional treatments are hindered by passive healing mechanisms and the need for immobilization. By designing a micro-electro-Nanofiber dressing composed of piezoelectric polyvinylidene fluoride (PVDF) integrated with antimicrobial silver nanoparticles (AgNPs), this research aims to address the dual challenges of promoting effective wound healing and maintaining joint mobility.Methods Herein, we developed a novel micro-electro-Nanofiber dressing using electrospinning technology, incorporating polyvinylidene fluoride (PVDF) with silver nanoparticles (AgNPs). The optimized PVDF-AgNPs Nanofiber dressings exhibited strong piezoelectric effects suitable for joint wounds.Results In vitro experiments demonstrated that the dressing effectively promoted fibroblast migration and collagen synthesis. In vivo, the dressing exhibited a trend of rapid healing in infected wounds within 12 days while modulating macrophage differentiation toward the anti-inflammatory M2 phenotype. Additionally, the incorporation of antimicrobial nanosilver effectively controlled local infections, further facilitating the healing process.Conclusion To sum up, by harnessing the piezoelectric effect to stimulate endogenous healing mechanisms without restricting joint mobility, the developed PVDF-AgNPs Nanofiber dressings represent a transformative approach for the treatment of wounds in highly mobile body areas.
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高影响因子
JOURNAL OF POWER SOURCES
·
2024
·
IF 8.1
Tianran Zhang,Bofeng Shi,Siyu Zhang,Mengfan Song,Jiping Wang,Lixue Zhang,Fang Kang
Due to the development of advanced electronic systems, there is an urgent need for polymer dielectric film capacitors with high breakdown strength ( E b ) and high discharge energy density ( U d ) at elevated temperatures. Herein, an all-organic blend polymer composite is fabricated by blending polyetherimide (PEI) and a trace amount of Poly(vinylidene fluoride) (PVDF), achieving nanoscale phase separation and forming interfaces between PEI and PVDF grain. The real permittivity ( ε r ) and E b of blend composites are simultaneously enhanced after PVDF introduction. It is worth noting that increasing the temperature does not reduce the E b of the PEI/xPVDF blend composite. Our Study shows that optimizing the plasticity and storage modulus of PEI/xPVDF significantly contributes to maintaining E b at elevated temperatures. Additionally, high temperatures enhance the entanglement of molecular chains at the PVDF-PEI interface, further supporting the preservation of E b . Finally, a high E b of 540 MV/m, a high U d of 5.92 J/cm 3 are achieved for the PEI/0.5PVDF blend at 150 °C. This work presents a new approach to enhance the E b of dielectric polymers by optimizing mechanical properties at high temperature, which providing a different strategy for enhancing the energy storage performance.
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