CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Weikang Zheng,Zongyang Li,Guanjie Lu,Tongxin Yang,Menghong Li,Chaohe Xu,Ronghua Wang
Lithium-ion capacitors (LICs) possess high energy density and power density simultaneously. However, for balancing electrochemical performance, mechanical properties and safety issues, the development of high-performance electrodes and electrolytes is still a challenge in this field. Herein, a 3D nitrogen-doped carbonaceous foam (N C) was synthesized by chemical vapor deposition (CVD), and the covering of poly(vinylidene fluoride- co -hexafluoropropylene) (PVDF-HFP) dramatically increase its flexibility without decreasing the electrochemical performance. The complete quasi-solid-state LICs using N C/PVDF-HFP as anode, N C/activated carbon (AC)/PVDF-HFP as cathode and PVDF-HFP as the skeleton of gel electrolyte are fabricated and shows good cycle stability (72.2 % after 2000 cycles). Meanwhile, the power density of the LIC can reach up to 342.5 W/kg when the energy density is 209.3 Wh/kg, and the power density can reach as high as 7632.2 W/kg at energy density of 77.6 Wh/kg, which is higher than many other dual-carbon and quasi-solid-state LICs.
✓ 已验证
产品关联
DOI
高影响因子
SENSORS AND ACTUATORS A-PHYSICAL
·
2022
·
IF 4.291
K. Prabakaran,P.J. Jandas,Jingting Luo,Chen Fu
Molecularly imprinted templates for L -Tryptophan sensor using hydrophilic poly (vinylidene fluoride) (PVDF) was fabricated through in-situ polymerization of 2-hydroxyethyl methacrylate (HEMA) within PVDF matrix. The work proposes a novel strategy for the integration of antifouling layer modification for water treatment technique into molecular imprinting polymer for surface acoustic wave (SAW) sensor fabrication and demonstrates their effective utilization in direct biological applications . The L -Tryptophan templates were carefully prepared on the delay line area of a SAW device prepared through photolithographic method internally. The imprinted template was qualitatively analysed using Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and atomic force microscopy (AFM) to understand the bond formation and distribution of imprinted textures on the receptor surface. Quantitative measurements as the L -Tryptophan receptor was conducted through SAW analysis within range of concentration 0.5–150 ng/ml and the sensor responded linearly with the varying concentration. The limit of detection and limit of quantification calculated to be 0.2 and 0.6 ng/ml, respectively. The mechanism of adsorption was further studied using Langmuir, Freundlich and Redlich-Peterson adsorption isotherm . The MIP modified SAW sensor had high selectivity in the presence of structural analogues such as D- tryptophan, ascorbic acid , leucine and tyrosine. The hydrophilic PVDF coated MIP-SAW sensor exhibited relatively high imprinting factor towards L -tryptophan of about 9.34.
✓ 已验证
产品关联
DOI
高影响因子
COMBUSTION AND FLAME
·
2022
·
IF 5.767
Wen Ao,Zhan Wen,Lu Liu,Yang Wang,Yu Zhang,Peijin Liu,Zhao Qin,Larry K.B. Li
In this experimental study, we explore how the combustion and agglomeration characteristics of solid propellants can be modified by replacing aluminum with ternary Al/CuO/PVDF(Polyvinylidene Fluoride) metastable intermolecular composites (MICs). Using thermogravimetric−differential scanning calorimetry, a laser ignition setup, and a high-pressure propellant combustion system , we examine the thermal reactivity, ignition behavior, burning rate, agglomeration, and condensed combustion products of various MICs-inclusion propellants. We find that the use of ternary Al/CuO/PVDF MICs can decrease the onset temperature and increase the oxidation efficiency of Al, as compared with common binary MICs. The ratio of CuO/PVDF is found to have a strong effect on the combustion intensity of the metallic powders , but only a weak effect on their ignition delay . Higher proportion of PVDF is found to have a negative effect on the combustion rate. Specifically, the combustion intensity is found to decrease first and then increase as the PVDF content increases. The exothermic Al/CuO reaction is found to alter the heat transfer of the condensed layer on the propellant surface, while PVDF plays a critical role in the thermal feedback of the gaseous reaction. When combined, these two factors lead to a ± 30% variation in the propellant burning rate. Furthermore, ternary MICs are found to reduce agglomeration during propellant combustion. The two optimal formulations are 2.5 wt.% CuO/2.5 wt.% PVDF and 3.5 wt.% CuO/1.5 wt.% PVDF. The use of these formulations is found to decrease the mean particle size of the condensed combustion products to only 11 μm, as compared with 76 μm for the original Al-inclusion propellant. High-speed microscope images reveal the existence of crack phenomena in the pockets surrounding the AP particles on the burning surface due to the Al/CuO reaction, as well as the floccule breakup mechanism of Al aggregates in the presence of PVDF, both of which reduce agglomeration. Overall, this study shows that replacing Al with ternary Al/CuO/PVDF MICs has significant effects on the agglomeration, combustion and ignition features of aluminized propellants. The findings of this study can be used to aid the development of highly adjustable functional catalysts for solid propellants.
✓ 已验证
产品关联
DOI
高影响因子
CARBON
·
2022
·
IF 11.307
Xueyan Wang,Zhong Liu,Xianfeng Liu,Ying Su,Jin Wang,Tingting Fan,Xin Ning,Seeram Ramakrishn,Yun-Ze Long
The accumulative disasters about oil spills and industrial emissions create increasingly environmental problems, and high-performance absorbent materials have attracted wide attention to providing available solution. Herein, polyvinylidene fluoride/SiO 2 @graphene oxide (PVDF/SiO 2 @GO) aerogels were prepared by cross-linking of the electrospun PVDF/SiO 2 nanofibers and GO skeleton. By changing the content of SiO 2 nanoparticles in the PVDF nanofibers, the porosity and surface roughness of the composite aerogels could be controlled. Compared with PVDF@GO aerogel, the PVDF/SiO 2 @GO (PSG) aerogels had higher mechanical properties and hydrophobicity . And, the PSG-2 aerogel (1 wt% SiO 2 contained in nanofibers) exhibited stable structure, excellent oil absorption capacity (129–264 g g −1 ), great flame retardancy and reusability . After being pretreated with strong acid and alkali, it remained strong hydrophobicity, indicating it possessed excellent chemical resistance. More importantly, it could also separate oil-water mixture by gravity under harsh environment (strong acid/alkali), which exhibited excellent separation performance with flux of 42402 L m −2 h −1 (chloroform/water mixture) and separation efficiency of 99.96%. Moreover, it could clean up viscous crude oil rapidly by photothermal effect, and the crude oil absorption time of heated PSG-2 was reduced by 99.65%. The PSG aerogels provide a new choice for efficient and continuous harsh environmental oil-water separation and crude oil absorption.
✓ 已验证
产品关联
DOI
高影响因子
Small
·
2022
·Vol. 18
·期 15
·2200114
·
IF 15.153
Lirong He,Jin Lu,Cheng Han,Xingang Liu,Jingfeng Liu,Chuhong Zhang
Piezoelectric pressure sensors are important for applications in robotics, artificial intelligence, communication devices, etc. The hyperboloid is theoretically predicted to be an unusual 3D structure that allows concerted piezoelectric enhancement owing to its synergistic effects of geometrical stress confinement and stress concentration, but has not been experimentally fulfilled due to a lack of efficient architecting techniques. In this work, a 3D hyperboloidal arrayed self-polarized PVDF piezoelectric energy harvester (PEH) is successfully fabricated by incorporating electrohydrodynamic (EHD) pulling technology into fused deposition modeling (FDM) 3D printing. This strategy not only simplifies the layer-by-layer constructing procedure for arrays, but simultaneously realizes a self-polarized and high β-phase (92%) PVDF PEH in a single electric-pulling step, saving posttreatment such as poling and removing excessive additives. Such a PEH delivers a significantly enhanced piezoelectric potential which is around 8 times that of a 2D flat film sensor. Moreover, this PEH featuring excellent linearity within a wide pressure regime, enables the sensing of human activities in a relatively large force range, which is otherwise difficult for traditional film sensors to differentiate. This work demonstrates a potential roadmap to advanced piezoelectric sensors exploiting unusual 3D structures enabled by the unique EHD pulling coupled 3D printing technique.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Applied Water Science
·
2022
·Vol. 12
·期 3
·1-11
·
IF 5.411
He Ting,Li Xiaogang,Wang Qian,Zhou Yue,Wang Xiaozu,Wang Zhaohui,Tavajohi Naser,Cui Zhaoliang
In this paper, ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate was the first time successfully utilized as single solvent in preparing the PVDF membrane with a good performance by N-TIPs method. The effects of quenching temperature and hydrophilic additive content on the morphology, permeability, and strength of the membranes were studied. All the prepared PVDF membranes were proved to be a pure β phase by FTIR and XRD, possessing a narrow pore size distribution. By adjusting quenching temperature and additive content, membranes with a flux of 383.2 L/m 2 h and concentrated pore diameter of 26 nm obtained.
✓ 已验证
产品关联
DOI
高影响因子
TEXTILE RESEARCH JOURNAL
·
2022
·
IF 2.455
Zhi Liu,Bing Gao,Xiaohai Huang,Huizhen Ke,Jin Xu
Herein, the unique wrinkled surface of polyvinylidene fluoride-hexafluoropropylene nanofibrous membrane was well developed by a one-step fabrication method just by adjusting the ratio of binary solvent and humidity. The well-tailored process was proposed complying with the evolutionary mechanism that a different volatilization temperature of binary solvent provides buffer time for the formation of a polymer/solvent-rich phase, subsequently water vapor solidifies the polymer jet, forming the unique surface on the resultant nanofiber. The intrinsic wrinkled surface structure enhances the roughness and endows the membrane with robust superhydrophobic characteristics. Meanwhile, the excellent mechanical property (stress at break 6.79 MPa, strain at break 136.8%) widens its applicability in industrial employment. Furthermore, the synthesized membrane exhibits stable results in oil–water separation in terms of good separation efficiency (>99.6%) and flux (>1100 l/m2h). This is a general approach for the synthesis of many other materials at lower cost and holds a great potential to be employed in practical engineering applications beyond the oil–water separation.
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2022
·
IF 10.383
Yanan Xiao,Fengwei Xie,Hao Luo,Rongxing Tang,Jiazi Hou
A naked-eye detector based on a rapid transmittance response to alcohol was designed to offer real-time and reusable detection of fruit freshness. To ensure the hydrophobicity of the fibrous membrane and high light transmission response to alcohol, fluorine-rich poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) with a low refractive index was selected as the shell layer, while sodium alginate (SA) and polyvinyl alcohol (PVA) were selected as the core layer for coaxial electrospinning. The core–shell fibrous detector was obtained by treatment with CaCl2 to form a stable hydrogel and by water flushing to remove PVA. The interior structure of the fiber and its evolution were investigated with increasing SA concentration, which changed from a nonconcentric structure to a core–shell structure. Without SA, nonconcentric structured fibers were obtained due to high flowability and incompatibility between the organic solvent phase of PVDF-HFP and the aqueous phase of PVA. As the SA concentration increased, the enhanced viscosity and surface tension decreased the asymmetric mobility significantly, which competed with the charge attractive forces from the Taylor cone surface, leading to a core–shell structure. The as-spun membranes were opaque due to light scattering at the interface between air and fiber and became light transparent after immersion in a rotten fruit-containing alcohol and acetic acid due to a decreased light loss. The rapidly responsive, reusable fibrous membranes with over 90% light transparency developed here have high potential for application in visual intelligent packaging to monitor the freshness of fruits and vegetables.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CARBON
·
2023
·
IF 10.9
Wen-Gang Cui,Xiaodi Zhou,Biao Zhao,Wenbin You,Yaxiong Yang,Bingbing Fan,Limin Wu,Renchao Che
Recently, the three-dimensional (3D) porous cellular foam derived from poly (vinylidene fluoride) (PVDF) via a simple CO 2 -assisted procedure has been widely applied as electromagnetic (EM) wave absorbing materials due to its one-step preparation process and high void fraction. However, delicate control of 3D microcellular structure by decoration of dielectric/magnetic components is still virgin. Herein, the hierarchical structure of 3D PVDF foam decorated with an ultra-low content of graphene nanoplates (5.0 wt%) and Ni nanochains (2.4 wt%) was successfully fabricated. The correlation between microcellular structure, and electrical conductivity/microwave absorption was systematically investigated. After introducing the conductive and magnetic components, a strong enhancement of dielectric loss, coming from the presence of conduction loss and polarization loss of 3D network, and magnetic loss, originating from strong eddy current loss and the natural resonance, was observed. Meanwhile, a high void fraction (∼92%) greatly optimized the impedance matching of incident waves and favored the multi-scattering. As a result, the superior microwave absorption was obtained, in which the effective absorption bandwidth (frequency with 90% microwave dissipation) can cover the whole K band (18–26.5 GHz) under the thickness of 3 mm. Overall, this work provides an ameliorated strategy for porous foams applied in microwave absorption.
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2023
·
IF 7.2
Zihan Tian,Yantao Song,Jing Zhang,Shuhao Qin,Yuanyuan Yang,Jianxin Li,Zhenyu Cui
Organic pollutants, such as dyes, contaminated water bodies seriously. Suitable materials and efficient technologies for degrading pollutants needed to be explored to protect the environment and human health. In this investigation, PVDF(PAA-g-β-CD)@TiO 2 hybrid film was prepared by a combination of “in situ hydrothermal-vapor induction” under mild conditions. The distribution, particle size, and interaction with the film surface for TiO 2 were investigated by XRD , XPS , SEM, and EDS . The TiO 2 nanoparticles were firmly immobilized and uniformly distributed on the hybrid film surface. Poly (acrylic acid) (PAA) and β-cyclodextrin (β-CD) on the film matrix were connected by the chemical bond, which provided stable nucleation and growth sites for TiO 2 while inhibiting photogenerated electron-hole recombination and significantly enhancing the adsorption ability. Furthermore, the multiple interaction forces (hydrogen bonding, coordination, and hydrophilic-hydrophilic interactions) between the film matrix and the TiO 2 were evaluated by simulated geometries and theoretical calculations. The multiple interactions reduced the band gap (Eg) while endowing the hybrid photocatalytic film with excellent degradation efficacy ( η ), stability, and recycling properties. Finally, the η of methylene blue (MB) reached 97.34 % within 120 min and remained above 90 % even after 8 reuses. It was believed that PVDF(PAA-g-β-CD)@TiO 2 film provided an approach for the mild preparation of polymer/TiO 2 hybrid film with high catalytic activity and optimization of photocatalytic properties.
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2023
·
IF 7.7
Ximeng Zhang,Fangbo Zhao,Liu Yang,Chengbao Geng,Hee-Deung Park,Hongxu Chen,Zhiguo Li,Ye Yang
The increasing utilization of polyvinylidene fluoride (PVDF) ultrafiltration membranes in water treatment has necessitated the development of membranes with superior separation, antifouling performance and high pure water permeability. As a hydrophilic and antibacterial modifier, quaternized graphene oxide (QGO) has been successfully applied to improve the antifouling and antibacterial properties of the membranes simultaneously. Herein, we proposed a simple and effective strategy to fabricate a nanocomposite ultrafiltration membrane by coating the PVDF membrane surface with QGO and using polydopamine (PDA) as a “bio-glue”. The filtration followed by cross-linking method was utilized to construct a “brick-mud” structure on the membrane surface. The prepared QGO/PDA-PVDF membrane exhibited favorable separation and antifouling properties (79.5% of BSA rejection rate, 15.7% of irreversible fouling rate when filtering 0.5 g/L BSA solution, 97.2% of E. coli and 96.3% of S. aureus antibacterial rate), while maintaining a high pure water permeability of 1105.4 L . m −2. h −1. bar −1 . QGO nanosheets were stably coated on the membrane surface, and the QGO/PDA-PVDF membrane prepared by this novel strategy also demonstrated application potential in the field of seawater desalination pretreatment . Besides, the possible mechanisms during modifications were also discussed. This research could serve as a reference for improving the comprehensive performance of PVDF ultrafiltration membrane through surface coating.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Ming Liu,Aikun Liu,Hongjian Zhang,Shuxuan Li,Yong Zhang
The coupling effect of piezo-photocatalytic technology is well demonstrated as a promising strategy for effective degradation of organic pollutants. However, the catalytic efficiency is dramatically limited by the undesirable neutralization of photogenerated electron-hole pairs. Herein, PVDF@Bi 2 MoO 6 /BiOBr heterojunction was designed elaborately to boosting their piezo-photocatalytic activity by built-in polarization field and controlled carrier transfer. The composite film presents excellent degradation performance of methyl orange (MO, 15 mg/L) (98.99%, 120 min) under the simultaneous ultrasonic vibration and visible light irradiation, which is around 2 and 3.1 times than that of individual piezoelectric and photocatalytic process. The improved piezo-photocatalytic capability could be attributed to the enhanced built-in piezoelectric field that generated by the vibration of p-type BiOBr nanosheets . The construction of piezoelectric polarization reduces the recombination efficiency of photogenerated carriers at the p-n heterojunction interface, thereby dramatically improving the catalytic efficiency. This work proposes and demonstrates the very positive role of dual piezoelectricity in modulating the photocatalytic efficiency in semiconductors, which provides a new paradigm for the further development of highly-efficient piezo-photocatalysts to be applied in environmental purification and wastewater treatment.
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）