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.
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PubMed
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.
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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.
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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.
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PubMed
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.
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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.
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高影响因子
POLYMER
·
2022
·
IF 4.432
Yuanlu Xu,Yueling Yu,Chunyang Song,Yi Zhu,Chengwen Song,Xinfei Fan,Zaijin You
The environmental pollution and resource loss caused by oil-water emulsion bring a severe threat to human's life. Superhydrophobic/superoleophilic membranes are considered as a wise choice for separating water-in-oil emulsions. However, the large-scale production of acid and alkali resistant, sustainable and efficient membranes remains an enormous challenge. In this study, a superhydrophobic/superoleophilic SiO 2 /PVDF (SP) membrane was prepared through facile sol-gel strategy in one step. Hydrophobic SiO 2 nanoparticles (NPs) were modified on PVDF membrane by hydrolysis and polycondensation reaction of tetraethyl orthosilicate (TEOS) and hexadecyltrimethoxysilane (HDTMS) as precursors. The low surface energy of the hydrophobic SiO 2 NPs and the micro/nano rough structures similar to the waxy protuberances of lotus leaves constructed by nano-SiO 2 played a crucial role in obtaining the superhydrophobic/superoleophilic property. The water contact angle (WCA) of the optimal SP membrane reached 152.4 ± 1.4°, while the oil droplets completely permeated the membrane in 1 s. Also, the fluxes of SP membrane for petroleum ether/water, n-hexane/water, and n-heptane/water were 3886 ± 140, 3551 ± 146 and 3763 ± 57 L m −2 h −1 , respectively, and the separation efficiencies were stable above 99.7%. Moreover, the SP membrane showed excellent separation effects and stability under different chemical environments. Most significantly, it also displayed anti-fouling performance like lotus leaves. The results indicated that its separation efficiency still remained above 97% after 20 cycles. Therefore, these outstanding results ensured the possibility of large-scale production and practical application of the SP membrane.
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高影响因子
Journal of Environmental Chemical Engineering
·
2022
·
IF 7.968
Chengbao Geng,Fangbo Zhao,Qiang Wang,Shuai Zheng,Yang Liu,Hongyan Niu,Jiaming Zhang,Hongxing Dong
To improve the anti-biofouling property of polyvinylidene fluoride (PVDF) membrane, three kinds of antibacterial graphene oxide (GO) derivatives were prepared, including imidazole-functionalized GO (Im-GO) and quaternized GO (Q-GO) synthesized by chemical grafting method, and GO loaded with silver nanoparticles (GO-Ag) synthesized by in-site reduction method. The structural characteristics and antibacterial abilities of three kinds of GO derivatives were characterized and investigated. It was demonstrated that GO could be used as a good carrier to prepare the anti-biofouling modifiers. Correspondingly, Im-GO/PVDF, Q-GO/PVDF, and GO-Ag/PVDF ultrafiltration membranes were fabricated using the phase inversion method. In contrast with the blank PVDF membrane, all the GO derivatives/PVDF membranes showed greatly improved permeability and anti-biofouling property. Significantly, the inhibition zone test and fluorescence staining experiment were carried out to investigate the differences between Im-GO, Q-GO, and GO-Ag in the antibacterial mechanisms. The corresponding results suggest that the imidazole and quaternary ammonium salt groups grafted on Im-GO and Q-GO possess great anti-leaching characteristics, while the loss of Ag + from GO-Ag is relatively obvious. Therefore, Im-GO and Q-GO synthesized by chemical grafting method have greater potential as the anti-biofouling membrane modifiers, considering the accumulation of harmful ions in water and possible reduction in antibacterial stability for GO-Ag.
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高影响因子
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.
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高影响因子
DESALINATION
·
2022
·
IF 11.211
Hailan Ji,Mengqi Gu,Ganwei Zhang,Chuan Yue,Zhiyuan Yuan,Dapeng Liu,Shusu Shen,Xiaoji Zhou,Ian Wyman
A Janus membrane with antiwetting and antifouling properties was prepared for complicated wastewater treatment via direct contact membrane distillation (DCMD) technology . The membrane was fabricated by directly depositing gallic acid (GA) and polyethyleneimine (PEI) onto one side of the PVDF/polydimethylsiloxane (PDMS) blend membrane. The results from different characterization methods demonstrate the successful fabrication of the Janus membrane. The obtained Janus membrane performs excellent antiwetting and antifouling properties because of its asymmetric wettability . When the 36 h DCMD test was carried out using the Janus membrane to treat feed solution containing 1000 mg/L crude oil, 0.3 mM SDS and 3.5 wt% NaCl, a relatively stable flux of 15.7 ± 0.2 Kg·m −2 ·h −1 was maintained, as well as the very small conductivity of 0.3 ± 0.0 μS/cm in the permeate side was kept. In addition, the as-prepared Janus membrane maintained stable when pH ranged from 1.0 to 11.0. Therefore, this Janus membrane can be a strong candidate in DCMD process to treat wastewater containing complicated contaminants.
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高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2021
·
IF 7.312
Jiuyun Cui,Atian Xie,Zhuo Yan,Yongsheng Yan
Although a great deal of superhydrophilic/underwater superoleophobic membranes has been developing for oil-water emulsion separation, most of them could be destroyed or lose their underwater superoleophobicity after exposure to complex conditions. In this study, a crosslinking modified PVDF/GO membrane with acid, alkali and high salt resistance was successfully prepared by a simple crosslinking process between acrylic acid and ethylene glycol dimethacrylate (EGDMA). The influences of content of acrylic acid on the membrane performance and structure evolution were investigated. The resultant composite membrane showed superior underwater superoleophobicity even in acid, alkali and salt environments. Additionally, the composite membrane could effectively separate various surfactant-stabilize emulsions under gravity-driven via wettability capillary effect with high rejection (>99%) and flux (>145 L m −2 h −1 ). The composite membrane also exhibited outstanding recyclability because of the stable covalent bridged multiple networks structure. The antifouling performance, stability and impressive recyclability make the composite membrane a promising candidate for long-term oil-water emulsion treatment.
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高影响因子
Nano Research
·
2021
·Vol. 14
·期 12
·4885-4893
·
IF 8.897
Chen Dongzhen,Zhang Liang,Ning Pan,Yuan Haozhi,Zhang Yu,Zhang Meng,Fu Tao,He Xinhai
Plasmonic surface of flexible multilayered nanofibers possesses special superiority for the surface-enhanced Raman scattering (SERS) sensing of molecules and microbial cells. However, the fabrication of flexible plasmonic nanofibers with high sensitivity and reproducibility is difficult. Herein, we report a smart strategy for fabricating flexible plasmonic fibers, in which compact and homogeneous gold nanoparticles (Au NPs) are in-situ grown on the high-curvature surface of multilayered fibers of electrospun polyvinylidene fluoride (PVDF). Firstly, the surface of PVDF fibers is changed electrically, and Au seeds are deposited on the surface of PVDF fibers using electrostatic driving force. Secondly, a stable AuI 4 − complex is formed employing coordination between I − and AuCl 4 − ions, which could decrease the reduction potential of AuCl 4 − and restrain the self-nucleation, and then the reduction reaction of AuI 4 − is initiated by introducing PVDF@Au seeds to pull down the barrier of potential energy. Finally, in-situ growth of AuNPs is generated on the high-curvature surface of PVDF nanofibers, and large-scale hotspots are generated by adjacent AuNPs coupling in the three-dimensional (3D) space of multilayered fibers. Membrane of PVDF@Au nanofibers also realizes the sensitive detection of thiram molecules (low limit of detection of 0.1 nM) and good reproducibility (relative standard deviation of 10.6%). Meanwhile, due to the multilayered construction of PVDF@Au nanofibers, a valid SERS signal on 3D surface of bacteria could be generated. 3D distribution of hotspots on multilayered PVDF@Au nanofibers gives a clear advantage for SERS sensing of organic molecules and microbial cells.
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高影响因子
危险品化学品经营许可证（带存储）