Journal of Materiomics
·
2023
·
IF 9.4
Xiao Chen,Yinda Li,Yunhao Lu,Jian Xie,Cheng Huang,Xiongwen Xu,Jian Tu,Xinbing Zhao,Tiejun Zhu
LiNi 0.8 Co 0.1 Mn 0.1 O 2 (NCM811) is considered as a promising cathode for high-energy-density solid-sate Li metal battery for its high theoretical capacity. However, the high oxidizability and structural instability during charge limit its practical applications. In this work, 1% (in mass) of nanosized Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 (LATP) was coated on NCM811 to enhance its electrochemical stability with a ceramic/polymer composite electrolyte. A robust, ultrathin (11 μm) composite electrolyte film was prepared by combining poly(vinylidene fluoride) (PVDF) with polyethylene oxide (PEO)-Li 6.5 La 3 Zr 1.5 Ta 0.5 O 12 (LLZTO). An in-situ polymerization process was used to enhance the interface between the PVDF/PEO-LLZTO (PPL) composite electrolyte and the LATP-coated NCM811 (LATP-NCM811). Coin-type Li|LATP-NCM811 cell with the PPL electrolyte exhibits stable cycling with an 81% capacity retention after 100 cycles at 0.5 C. Pouch-type cell was also fabricated, which can be stably cycled for 70 cycles at 0.5 C/1.0 C (80% retention), and withstand abuse tests of bending, cutting and nail penetration. This work provides an applicable method to fabricate solid-state Li metal batteries with high performance.
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高影响因子
ACS Applied Materials & Interfaces
·
2021
·
IF 9.229
Zebang Luo,Jing Chen,Zhengfang Zhu,Lin Li,Yi Su,Wei Tang,Olatunji Mumini Omisore,Lei Wang,Hui Li
Flexible pressure sensors have attracted increasing attention because they can mimic human skin to sense external pressure; however, for mimicking human skin, the sensing of a pressure point is far from sufficient. To realize fully biomimetic skins, it is crucial for flexible sensors to have high resolution and high sensitivity. We conducted simulations and experiments to determine the relationship between the sensor sensitivity and physical parameters, such as the effective relative permittivity and air ratio of the dielectric layer. According to the results, a micropillar–poly(vinylidene fluoride) (PVDF) dielectric layer was designed to achieve high sensitivity (0.43 kPa–1) in the low-pressure regime (<1 kPa). An 8 × 8 pixel sensor matrix was prepared based on a micropillar–PVDF (MP) film and electrode array (MPEA) to detect the pressure distribution with high resolution (13 dpi). Each pixel could reflect the point of applied pressure through an obvious change in the relative capacitance; moreover, objects with various geometries could be mapped by the pixels of the flexible sensor. A counterweight, a plastic flag, and pine leaves were placed on the flexible sensor, and the shapes were successfully mapped; in particular, the mapping of the ∼0.005 g ultra-lightweight pine leaves with a length of 7 mm and a width of 0.6 mm shows the high sensitivity and high resolution of our flexible pressure sensor.
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PubMed
高影响因子
Membranes
·
2021
·Vol. 11
·期 6
·420
·
IF 4.106
Tianshu Liu,Xiaoji Zhou,Yizhuo Sun,Renbi Bai
In this study, PVDF/PTFE composite membranes were prepared by adding a PTFE nanoemulsion to a PVDF solution and casting it through the conventional non-solvent-induced phase separation method. The objective was to explore the effectiveness of using a simple and economical method to modify PVDF membranes with PTFE to enhance their anticorrosion performance, especially under highly acidic or alkaline conditions. PTFE nanoparticles (of around 200 nm in size) in nanoemulsion form were blended with PVDF at a mass ratio of PTFE:PVDF in the range of 0–0.3:1. The obtained membranes were examined to determine the effect of the added PTFE nanoparticles on the structure of the modified PVDF membranes as well as on their mechanical strength and surface characteristics. The membranes were then immersed in various concentrations of acidic or alkaline solutions for varied durations ranging from a few days up to as long as 180 days (6 months). The impacts of by the corrosive solutions on the tensile strength, surface roughness, and water flux of the membranes with different exposure times were quantified. The results showed that although a certain extent of change may occur with extended immersion times, greatly enhanced anticorrosion performance was obtained with the prepared PVDF/PTFE membranes compared with the unmodified PVDF membrane. For example, after being immersed in 5 mol-H+··L−1H2SO4, HCl, and HNO3solutions for 6 months, the tensile strength at breaking point remained at up to 69.70, 74.07, and 71.38%, respectively, of the initial strength for the PVDF/PTFE (M30) membrane. This was in contrast to values of only 55.77, 70.43, and 61.78% for the unmodified PVDF membrane (M0). Although the water flux and surface roughness showed a change trends to the tensile strength, the PVDF/PTFE (M30) membrane had much higher stability than the PVDF (M0) membrane. In a continuous filtration experiment containing H2SO4at 0.01 mol-H+·L−1for 336 h (14 days), the PVDF/PTFE membrane showed a maximum flux change of less than 30%. This was in comparison with a change of up to 50% for the PVDF membrane. However, the PVDF/PTFE membranes did not seem to have a greatly enhanced anticorrosion performance in the alkaline solution environment tested.Keywords:PVDF/PTFE composite membrane;PTFE nanoparticle;polymer blending;non-solvent induced phase separation method;anticorrosive performance
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高影响因子
Materials Advances
·
2021
·Vol. 2
·期 10
·3300-3314
·
IF 0
Xing-Xing Ni,Jian-Hua Li,Lu-Ping Yu
A novel and versatile active–passive integrated strategy to integrate both antifouling and antibacterial properties into PVDF membranes was developed. PDA microspheres on modified membranes served as primers, and we proposed that a “PDA guiding effect” existed during the modification process. Specifically speaking, it was a guiding reduction effect from the PDA microspheres toward Ag+ and a guiding generation effect toward L-cysteine that were separately in favor of the generation of AgNPs and cysteine flowers in cross-sections of the membranes. In addition, the active–passive integrated strategy presented in this research simultaneously includes both an anti-adhesion approach for reducing the initial adsorption of organisms and an anti-bacterial approach for suppressing the activities of attached organisms on the membranes. Conventional filtration experiments clearly demonstrated that the zwitterionic characteristics of L-cysteine made it possible to greatly reduce the initial adhesion of foulants and the deposition of dead bacteria on the membranes. Various bacteria-based experiments proved that AgNPs were effective at preventing the growth, proliferation, and colonization of microorganisms, as well as the accompanying membrane biofouling after long-term operation. Furthermore, self-driven filtration experiments, natural organic matter (NOM) solution filtration experiments, and protein adsorption tests were also carried out to evaluate the practical applications of the modified membranes. In this research, the PDA guiding effect was directed toward inorganic AgNPs and organic L-cysteine. This effect has great possibilities to be extended to other functional materials and to be broadly applied in the construction of diverse functionalized surfaces.
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RSC Advances
·
2021
·Vol. 11
·期 31
·19128-19135
·
IF 3.361
Tong Ye,Hongye Li,Mingyue Du,Xiaowei Ma,Xiaolin Liu,Lixiong Wen
Polymer-based dielectric nanocomposites as raw materials of dielectric capacitors used in advanced electronics and electrical systems have a great application prospect but remain a huge challenge to energy storage performance in high electric fields. In this work, MgAl layered double hydroxide (MgAl LDH) nanosheets loaded with Ni nanoparticles were designed and synthesized, and incorporated into polyvinylidene fluoride (PVDF) to fabricate Ni–MgAl LDH/PVDF nanocomposites with high energy density. The effect of Ni–MgAl LDH nanosheet content (0.2 to 0.8 wt%) on the energy storage performance of MgAl LDH/PVDF nanocomposites was studied. As a result, after adding 0.6 wt% Ni–MgAl LDH nanosheets, the nanocomposites obtained the highest energy density 23.87 J cm−3 (at 640 kV mm−1) and the charge–discharge efficiency reached 65%, which was 76% and 18% higher than that of pure PVDF, respectively. This improvement could be attributed to the multiple functions of Ni–MgAl LDH nanosheets under an applied electric field. On the one hand, Ni nanoparticles on the surface of the MgAl LDH nanosheets could enhance the interfacial conductivity, form plenty of parallel micro-capacitors and produce Coulomb blockade effect, which resulted in high dielectric constant and high breakdown strength. On the other hand, two functions contributed by MgAl LDH nanosheets, homogenizing the electric field and inhibiting the growth of the electric tree coming from its medium dielectric constant and sheet structure, were beneficial to increase the breakdown strength. Furthermore, finite element simulations were employed to explain the mechanism of improved dielectric properties of the Ni–MgAl LDH/PVDF nanocomposites.
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高影响因子
ACS Applied Materials & Interfaces
·
2021
·
IF 9.229
Lei Wang,Jiawei Yan,Ran Zhang,Yanfang Li,Wenzhuo Shen,Jiali Zhang,Min Zhong,Shouwu Guo
Gel electrolytes show certain advantages over conventional liquid and solid electrolytes, but their mechanical strength and surface adhesion to the electrode remain to be improved. To address the challenges, we design and fabricate herein the core–shell nanofiber mats in situ on the LiFePO4 electrode as matrices for gel electrolytes, in which the core is poly(m-phenylene isophthalamide) (PMIA) nanofiber and the shell are composite of Al2O3 nanoparticles and poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP). The mechanical property of the core–shell polymeric nanofiber mats and their surface interaction with LiFePO4 electrode are characterized complementarily using dynamic thermomechanical analysis and scanning electron microscopy. The electrochemical properties of the gel electrolytes based on the as-prepared matrices after being loaded with lithium salt solution are studied systematically on half coin cells. It is found that the ultimate strength of the core–shell PMIA@PVdF-HFP/Al2O3 mat can reach 6.70 MPa, 2 times higher than that of the PVdF-HFP/Al2O3 nanofiber mat. Meanwhile, the shell PVdF-HFP/Al2O3 can ensure manifest surface affinity to the LiFePO4 electrode and enhance lithium-ion conductance. Thus, the as-assembled LiFePO4 half coin cells using PMIA@PVdF-HFP/Al2O3 gel electrolyte show good electrochemical performances, especially the long cycle stability with the capacity retention of 96.6% after 600 cycles under 1C.
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高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Na Zhang,Na Yang,Luhong Zhang,Bin Jiang,Yongli Sun,Jingwen Ma,Kai Cheng,Feifei Peng
Wettability of porous materials is crucial for the separation of emulsified oil/water mixtures. Herein, high hydrophobicity of polyvinylidene fluoride (PVDF) membrane has been facilely transformed to high hydrophilicity and underwater superoleophobicity via single-step coating of plant-derived epigallocatechin gallate (EGCG) and silver ion (Ag + ) in aqueous solution. EGCG can chelate with Ag + and in-situ reduced it into Ag nanoparticle, meanwhile Ag/EGCG composite was adhered on membrane surface due to the high surface binding affinity of EGCG. The hydrophilic EGCG and formed micro/nanostructure together improved membrane hydrophilicity and oleophobicity. The optimally Ag/EGCG modified PVDF membrane possesses high permeate flux (e.g. 735 L/(m 2 h) for diesel-in-water emulsion, while it is zero for pristine PVDF membrane) under a low operation pressure of 0.5 bar and high oil rejections in the treatment of surfactant-stabilized oil-in-water emulsions consisting of micro/nano scale droplets. In addition, the membrane exhibits excellent antifouling property with a flux recovery ratio of 98.1% and satisfactory reusability in a 5-cycle test. Moreover, the membrane possessed desired stability during long-term rinsing test and Ag leaching test. This work would offer new insights into surface hydrophilic manipulation of porous membrane towards practical oil emulsion purification.
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高影响因子
APPLIED SURFACE SCIENCE
·
2020
·
IF 6.182
Guanliang Chen,Xiujuan Lin,Jianan Li,Shifeng Huang,Xin Cheng
Polymer-based composites comprising of high dielectric constant ceramic nanoparticles are widely used in dielectric capacitors due to their excellent energy storage and processing properties. In this study, ultra-small Ni nanoparticles were used to fabricate core-satellite structured hybrid Ni@BT nanoparticles. Compared with BT/PVDF composites, the Ni@BT/PVDF nanocomposites exhibited the enhanced energy storage properties due to the low electric conductivity, small dielectric loss and improved breakdown strength. The maximum discharged energy density reached 9.55 J/cm 3 for nanocomposites with 3 vol% Ni@BT at the electric field of 350 kV/mm, which was nearly eight times of commercial BOPP (1.2 J/cm 3 at 640 kV/mm) and was around 208% compared to the pristine PVDF (4.58 J/cm 3 at 340 kV/mm). The improved energy density of the nanocomposites could be attributed to the Coulomb-blockade effect of the introduced ultra-small Ni nanoparticles exactly. This work provides an effective approach to improve the energy storage property of dielectric nanocomposites.
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高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2021
·
IF 7.312
Junkai Gao,Miaomiao Cai,Zeguang Nie,Junwei Zhang,Yan Chen
Wettability and roughness modification of membrane surface are crucial for its utilization in the separation of oil/water mixture and emulsion. However, traditional modification method for membrane had the drawbacks of high cost, complex preparation and low flux. In this study, for the first time, based on tannic acid (TA), Cu 2+ and ethylenediaminetetraacetic acid disodium salt (EDTA-2Na), a novel, facile, and cost-effective interface engineering method for significantly enhancing the flux and separation efficiency of polyvinylidene fluoride (PVDF) microfiltration membrane for oil/water mixture and emulsion was developed via in situ extraction of metal ions. TA and Cu 2+ could form TA-Cu 2+ complex which could deposit on the surface of PVDF microfiltration membrane, and then Cu 2+ was extracted by EDTA-2Na, which not only enhanced the surface roughness and wettability of the membrane, but also reserved the porous structure of the matrix membrane. The resulted membrane possessed superhydrophilicity and underwater superoleophobicity, which showed high membrane fluxes of 8841.94 Lm −2 h −1 bar −1 and 1440 Lm −2 h −1 bar −1 for oil/water mixtures and emulsified oil respectively, and the separation efficiency of TA/EDTA-2Na/PVDF could reach 99.99%. Moreover, the membrane still exhibited excellent stability after long soaking treatment in NaCl solution for 48 h. Thus, in this study, a new strategy for membrane surface modification was developed, which had considerable promise for real application of oily wastewater treatment.
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高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2019
·
IF 7.015
Xinya Wang,Changfa Xiao,Hailiang Liu,Mingxing Chen,Hongyan Xu,Wenpeng Luo,Fan Zhang
In this study, a novel and multifunctional polyvinylidene fluoride-co-hexafluoropropyle (PVDF-HFP)/catechol-polyethyleneimine (CA-PEI)/Ag/3-glycidyloxy propyltrimethoxysilane (KH560) tubular nanofiber membrane (TNM) for applications in dye degradation and oil/water separation was fabricated. Firstly, the PVDF-HFP tubular nanofiber membranes were modified by using a mussel-inspired method. Then, Ag nanoparticles were assembled on the nanofiber surface to improve their excellent catalytic capacity for Methylene blue (MB) and Congo red (CR). Finally, the hydrophilic KH560 was grafted on nanofiber surface and the effects of KH560 concentration on the membrane performance were investigated. The results showed that when the KH560 concentration was 3 wt%, the modified membranes possessed a higher hydrophilicity and permeability. Meanwhile, it could also effectively separate various oil-in-water emulsions with high separation rate and separation efficiency at 0.02 MPa. Moreover, the catalytic and oil/water separation performances had no discernible decay after ten cycle tests, which promoted the potential application of modified PVDF-HFP TNMs for the treatment of practical oily wastewater.
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高影响因子
CERAMICS INTERNATIONAL
·
2019
·
IF 3.45
Yefeng Feng,Qihuang Deng,Cheng Peng,Qin Wu
Although high permittivity is achieved in barium titanate (BT) filled polymer nanocomposites , severely reduced insulation and breakdown properties are frequently found due to overload and agglomeration of BT nanoparticles with ultrahigh specific area. To simultaneously realize high permittivity and breakdown strength , in this work, unfunctionalized 2D Ti 3 C 2 MXene nanosheets with 2 wt% weight concentration were introduced to prepare ternary BT/MXene/polymer nanocomposites by solution cast process. Employing low-concentration conductive MXene instead of high-concentration ferroelectric BT could lead to significant improvement of permittivity of ternary composites, ascribed to remarkably increased interface types and enhanced interface polarization. In comparison to binary BT/polymer composites, ternary composites could have slightly improved dielectric loss and conductivity as well as gracefully reduced breakdown strength, attributed to finely retained high interface compatibility and filler dispersion. Ternary composite containing 8 wt% BT and 2 wt% MXene had a permittivity of 77, loss of 0.15 at 100 Hz and breakdown strength of 220 MV m −1 . This work might open the door to large-scale fabrication of promising composites with high permittivity and breakdown strength under low filler loading (~ 10 wt%).
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高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2019
·
IF 7.015
Haicheng Jiang,Qi Zhao,Panpan Wang,Jun Ma,Xuedong Zhai
Fabricating high-flux, low-fouling gravity-driven membranes (GDM) has proved to be an extremely challenging work. In this study, a novel tailored amphiphilic multi-arms polymer poly(propylene glycol)-silane-poly(ethylene glycol) (PPG-Si-PEG) was synthesized and blended into Polyvinylidene Fluoride (PVDF) matrix to fabricate GDM via nonsolvent induced phase separation method. The incorporation of multi-arms polymers affected phase separation and surface segregation behaviors, resulting in the formation of more porous structure, which were demonstrated by scanning electron microscopy (SEM). Moreover, the hydrophilic PEG arms in polymers were enriched onto membrane surface through surface segregation and utilized to improve the hydrophilicity of membranes, which were confirmed by Fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS) and contact angle measurement. The separation and antifouling properties of the membranes were evaluated by using gravity as the driving force, employing bovine serum albumin (BSA) as the model foulant. The water flux of membranes increased from 4.6 L m −2 h −1 for the control membrane to 12.1 L m −2 h −1 for PVDF/PPG-Si-PEG∼5% membrane. The antifouling properties of modified membranes were effectively improved in comparison with that of control membrane. The flux recovery ratio, especially for PVDF/PPG-Si-PEG∼5% membrane, was up to 99.4%. This study provided a new method for antifouling modification of GDM.
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高影响因子
危险品化学品经营许可证（带存储）