RSC Advances
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2021
·Vol. 11
·期 47
·29527-29536
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IF 3.361
Lian Sun,Quanchao Gu,Honglei Wang,Jinshan Yu,Xingui Zhou
A high-temperature proton exchange membrane was fabricated based on polyvinylidene fluoride (PVDF) and polyvinylpyrrolidone (PVP) blend polymer nanofibers. Using electrospinning method, abundant small ionic clusters can be formed and agglomerated on membrane surface, which would facilitate the proton conductivity. To further enhance the conductivity, phosphoric acid (PA) retention as well as mechanical strength, sulfamic acid (SA)-doped metal–organic framework MIL-101 was incorporated into PVP-PVDF blend nanofiber membranes. As a result, the anhydrous proton conductivity of the composite SA/MIL101@PVP-PVDF membrane reached 0.237 S cm−1 at 160 °C at a moderate acid doping level (ADL) of 12.7. The construction of long-range conducting network by electrospinning method combined with hot-pressing and the synergistic effect between PVP-PVDF, SA/MIL-101 and PA all contribute to the proton conducting behaviors of this composite membrane.
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高影响因子
JOURNAL OF MEMBRANE SCIENCE
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2021
·
IF 8.742
Yang He,Kexin Xu,Xia Feng,Li Chen,Zhongyi Jiang
Hydrophilic polymer brushes on membrane surfaces can alleviate fouling during the separation of oil/water emulsions; the charged moieties on the polymer brushes presumably interact with charged surfactants and weaken the membrane fouling behaviour. However, the oil-repellence mechanism of nonionic polymer brushes has not been thoroughly examined. In this study, a nonionic poly(N-acryloyl morpholine)-brush-grafted-poly(vinylidene fluoride) membrane (PVDF- g -PACMO) was fabricated via surface-initiated atom transfer radical polymerisation (ATRP) to separate various surfactant-stabilised emulsions. PVDF- g -PACMO membranes with high hydrophilicity and high permeation were successfully fabricated by controlling the duration of ATRP. Furthermore, fouling models of oil/water emulsions stabilised by anionic, nonionic, and cationic surfactants were examined. Multicycle filtration experiments revealed that the anionic surfactant-stabilised emulsions severely fouled the similarly charged PVDF- g -PACMO membranes owing to electrostatic repulsion, whereas the nonionic and cationic surfactant-stabilised emulsions exhibited reduced irreversible fouling. In particular, an unusual relief in irreversible membrane fouling was observed with respect to the cationic surfactant-stabilised emulsions, presumably because of strong demulsification and steric effects (surfactant barrier), which repelled the penetration of oil droplets into the internal pores and averted pore blockage. These observations suggest that oppositely charged surface potentials of the PVDF- g -PACMO membranes compared to that of the oil/water emulsions assist in mitigating irreversible fouling. The mechanisms examined herein described the relationship between the surface properties of the oil/water emulsions and the tendency for irreversible fouling, thereby providing valuable guidance for sustainable separation of oil/water emulsions.
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SEPARATION AND PURIFICATION TECHNOLOGY
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2019
·
IF 5.107
Anran Zhou,Ruibao Jia,Yonglei Wang,Shaohua Sun,Xiaodong Xin,Mingquan Wang,Qinghua Zhao,Huanhuan Zhu
The technique of coupling photocatalysis and membrane filtration was applied to the abatement of sulfonamide antibiotics in water. TiO 2 photocatalyst has been aroused widespread concern in recent years due to its low price and easy availability. A PVDF-PVP-TiO 2 -Dopamine blend ultrafiltration membrane (PPTD) was first fabricated in this study and removal of sulfadiazine (SD) in water using a PPTD membrane filtration-photocatalysis system was realized. The addition of PVP-TiO 2 -Dopamine increased the porosity and average pore size of membranes, resulting in improved hydrophilicity, flux of modified membranes. In pure water, the SD removal efficiency was 91.4% with a first-order rate constant k 0.0216 min −1 under the optimum conditions ([SD] 0 = 0.4 µmol/L, UV = 125 µW/cm 2 , pH = 7.5 ± 0.1, t = 2 h). Water quality parameters (NO 3 − , Cl − , SO 4 2− , humic acid (HA)) showed quite different effects on SD decontamination. Simulated degradation experiments using real samples demonstrated that PPTD membrane filtration-photocatalysis system has significant potential with regard to controlling SD as pollutants in water. The photocatalytic mechanism characterized using ESR indicated that OH was largely responsible for SD decontamination. The mechanism of the PPTD membrane filtration-photocatalysis system suggests that TiO 2 -Dopamine could exist synergistically through the bidentate structure or the chelated structure, and that OH, O 2 − , HO 2 , H 2 O 2 and 1 O 2 may be produced in the PPTD membrane filtration-photocatalysis system.
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JOURNAL OF APPLIED POLYMER SCIENCE
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2019
·Vol. 137
·期 24
·48804
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IF 2.188
Yan Feng,Runjun Sun,Chengkun Liu,Meiyu Chen,Qiushi Wang
The electrospun polyamide 6 (PA6) membranes are treated with different methods. The rough surfaces with different protuberances size and the fiber diameter are prepared by wet, dry heat, wet heat, and ethanol treatments under relaxation, and the formation mechanisms are analyzed. A relative stable structure of PA6 membrane is also prepared by ethanol treatment under tension, and its structure is as same as the untreated membrane. The dynamic water contact angles (WCAs) of the treated membranes are measured. The starting WCA of the membrane with wet heat treatment under relaxation is 90.95°, which is larger than those of wet, dry heat, and ethanol treatments under relaxation. The effects of surface morphologies with different treatments on wettability are analyzed. For obtaining hydrophobicity, the membrane with wet heat treatment under relaxation was coated by polyvinylidene fluoride (PVDF). The WCA of the membrane increases to 127.1° after coating. From another point of view, the WCA of the PVDF/treated PA6 membrane is much larger than that of the pure casting PVDF membrane, which means the rough surface of the treated PA6 membrane can improve the hydrophobicity of the PVDF membrane. Furthermore, the membrane is endowed with superhydrophobicity (WCA of 153.5°) after being coated by SiO 2 /PVDF due to the multilevel structured surface roughness. It is a relative low cost and convenient operation method to prepare the superhydrophobic material. The results provide a novel preparation method of the superhydrophobic material and a treatment method of the electrospun PA6 membrane to obtain a stable structure. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137 , 48804.
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FUEL
·
2019
·
IF 5.128
Chen Li,Yuefei Song,Xudong Wang,Quan Zhang
Sulfonated titanium dioxide (S-TiO 2 ) was prepared by the grafting of sulfonic groups onto TiO 2 , and doped into the PVDF-g-PSSA as a highly efficient inorganic additive, thus achieving simultaneous improvement of the proton conductivity and anti-fouling property of the synthesized S-TiO 2 /PPSSA proton exchange membrane (PEM). The S-TiO 2 /PPSSA membrane was implemented in microbial fuel cell (MFC) for the first time, and its physicochemical properties and performance in MFC were studied. A new technique of combining Quartz crystal microbalance with dissipation with membrane spin-coated sensors made by a spin coating method was utilized to provide an insight into the anti-fouling property of the prepared membranes. The implementation of Fourier transform infrared spectrometry and X-ray photoelectron spectroscopy demonstrated TiO 2 was successfully introduced into the sulphonic groups. The S-TiO 2 /PPSSA-5.0 membrane has a significant increase in the water uptake (40.9%) and proton conductivity (0.067 S/cm) compared with the PVDF-g-PSSA membrane. QCM-D results indicated that it has better anti-fouling property than pristine membrane and Nafion 117. Moreover, the MFC with the S-TiO 2 /PPSSA-5.0 membrane exhibited a maximum power density of 130.54 mW/m 2 , very close to that of Nafion 117 (132.02 mW/m 2 ), but had the highest COD removal of 91% and least bio-fouling adsorption. These results demonstrate that the blending of sulfonated organic polymers and sulfonated inorganic additives can improve the electrochemical and anti-fouling properties of the composite membranes, which is a new concept for the preparation of PEM suitable for MFC. The S-TiO 2 /PPSSA-5.0 composite PEM is an appropriate candidate separator for the large-scale application of MFCs.
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SEPARATION AND PURIFICATION TECHNOLOGY
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2019
·
IF 5.107
Shugang Xu,Yuanfa Liu,Yue Yu,Xitong Zhang,Jun Zhang,Yanfen Li
The polyacrylonitrile/polyvinylidene fluoride (PAN/PVDF) chelating membrane with amidoxime groups was prepared to simultaneously remove metallic and organic pollutants from mimic industrial wastewater. The main purpose of this study is to investigate the interaction between metal ions and protein molecules, and synergistic effects on the pollutant removal efficiency through the chelating membrane. Lysozyme and bovine serum albumin (BSA) were used as organic pollutants and Cu 2+ , Pb 2+ and Cd 2+ were used as metal components in this study. As one of the metal ions (Cu 2+ , Pb 2+ or Cd 2+ ) and one of the proteins (lysozyme or BSA) are present in the solution, the metal removal rate is improved due to the interaction of metal ions with protein, to form a metal-protein complex. At the same time, the lysozyme rejection efficiency decreases, but the BSA rejection efficiency increases. For the mixture consisting of one metal ion and two proteins, the metal removal rate is higher than that for the case (one metal ion + lysozyme), but lower than that for the case (one metal ion + BSA). Meanwhile, the protein retention efficiency decreases, since the interaction between lysozyme and BSA disturbs the retention efficiency of each protein. As three metal ions and two proteins are present in the solution, the ion removal efficiency is significantly improved, and the protein retention efficiency is increased as well, which is due to the fact that there are much more chances for forming metal-protein complexes.
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Polymers
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2019
·Vol. 11
·期 12
·1975
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IF 3.164
Lili Wu,Qiuhu Lin,Cong Liu,Wanyu Chen
A hydrophilic and anti-fouling coating layer was constructed on a polyvinylidene fluoride (PVDF) microfiltration membrane by a novel surface modification method. The pristine membrane was firstly coated by (3-chloropropyl) trimethoxysilane/polyethyleneimine and tannic acid. Then, the metal ion was induced on the coating layer to coordinate with tannic acid and polyethyleneimine, forming a more stable and hydrophilic coating on the surface. The membrane’s surface morphology and chemical element analysis showed that the Tannic acid/ polyethyleneimine (TA/PEI) coating layer was denser and had more stability after the addition of metal ions, and this may be due to the coordination bond formed between the TA/PEI coating and metal ions. The results of the water contact angle and pure water flux measurements showed that the hydrophilicity and wettability of the modified membranes were improved obviously after introducing the metal ion layers. The anti-fouling performance and stability of the modified membrane were also characterized by the underwater oil contact angle (OCA), the separation efficiency, and the contact angle variation value for before and after the rinsing experiment. The modified membrane showed obvious stability and antifouling. Moreover, the retention rate of some composite membranes could reach 99.6%.Keywords:surface modification;metal ion;anti-fouling;retention rate
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高影响因子
MATERIALS CHEMISTRY AND PHYSICS
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2019
·
IF 2.781
Lingfang Li,Changling Fan,Bin Zeng,Muchu Tan
The effect of pyrolysis temperature on the electrochemical performance of cellulose-derived hard carbon as anode material for lithium ion batteries was discussed in detail. Because of the presence of more oxygen-containing groups, the hard carbon pyrolyzed below 700 °C has larger irreversible capacity. The initial coulombic efficiency is low and the capacity decreases rapidly. X-ray photoelectron spectroscopy (XPS)results show that the ratio of C O to C–O bond becomes very small when higher than 800 °C, most of the oxygen-containing groups and hydrogen disappears. Hard carbon obtained at 1100 °C has higher initial coulombic efficiency and better cycle performance, no voltage hysteresis exists. The number of micropores of HC-1100 is much larger than that of mesopores, which reduces the irreversible deposition of lithium ions in mesopores. However, due to the decrease of interlayer space, lithium storage sites become less and the capacity is a bit lower than HC-800 and HC-950. The hard carbon obtained in 800–1000 °C range has the best comprehensive performance in charge-discharge capacity, initial coulombic efficiency and cycle performance.
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JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
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2018
·
IF 3.609
Ying Gong,Wenying Zhou,Zijun Wang,Li Xu,Yujia Kou,Huiwu Cai,Xiangrong Liu,Qingguo Chen,Zhi-Min Dang
In this work, graphene oxide (GO) nanosheets with surface modification by Tannic and Fe coordination complexes (TA-Fe) were incorporated into poly(vinylidene fluoride) (PVDF) to prepare high constant but low loss polymer nanocomposites , and the effect of TA-Fe interlayer on dielectric properties of the GO@TA-Fe/PVDF nanocomposites was investigated. The results indicate that the dosage, mixing ratio, and reaction time of TA-Fe complexes have obvious influences on the dielectric properties of the nanocomposites. Furthermore, the TA-Fe interlayer significantly influences the electrical properties of GO@TA-Fe nanoparticles and their PVDF composites, and the GO@TA-Fe/PVDF composites exhibit superior dielectric properties compared with raw GO/PVDF. Dielectric losses of the GO@TA-Fe/PVDF are significantly suppressed to a rather low level owing to the presence of TA-Fe layer, which serves as an interlayer between the GO sheets, thus preventing them from direct contacting with each other. Additionally, the dynamic dielectric relaxation of the GO/PVDF and GO@TA-Fe/PVDF nanocomposites was investigated in terms of temperature.
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POLYMER ENGINEERING AND SCIENCE
·
2018
·Vol. 59
·期 1
·103-111
·
IF 1.551
Ying Gong,Wenying Zhou,Xuezhen Sui,Yujia Kou,Li Xu,Yue Duan,Fuxin Chen,Ying Li,Xiangrong Liu,Huiwu Cai,Qingguo Chen,Zhi-Min Dang
Surface modification of core-shell structured Al (Al@Al 2 O 3 ) nanoparticles was performed using γ -(Aminopropyl)-triethoxysilane (APS) and dopamine (DA), respectively, and the microstructures, dielectric properties and thermal conductivities of the Al/poly(vinylidene fluoride) (PVDF) nanocomposites were investigated. Both DA and APS enhance the interfacial bonding strength between the fillers and the matrix, leading to homogeneous dispersion of Al nanoparticles in PVDF matrix. Compared with raw Al nanoparticles, surface-treated Al/PVDF exhibit much higher dielectric permittivity due to the enhanced interfacial interactions between the two components, whereas, the dielectric loss and electric conductivity of the nanocomposites still remain at rather low levels owing to the insulating alumina shell preventing effectively core Al from direct contact. The dynamic dielectric properties results reveal that dielectric constant and loss increase with temperature due to the gradually enhanced mobility of molecular chain segments of PVDF for the raw Al/PVDF and treated Al/PVDF nanocomposites. Additionally, the PVDF nanocomposites with Al treated with APS and DA show enhanced thermal conductivities compared with raw Al/PVDF under the same filler loading because of reduced thermal interfacial resistance promoting phonon transfer across the interfaces. POLYM. ENG. SCI., 59:103–111, 2019. © 2018 Society of Plastics Engineers
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INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2018
·
IF 3.141
Luqing Zhang,Zhongkai Zhu,Umair Azhar,Jiachen Ma,Yabin Zhang,Chuanyong Zong,Shuxiang Zhang
An innovative strategy is devised to obtain poly(vinylidene fluoride) membranes with splendid fouling resistance using amphiphilic block copolymer containing poly(vinylidene fluoride) (PVDF) segments as modification agent. The PVDF-based block copolymer with poly[2-(N,N-dimethylamino) ethyl methacrylate] as the hydrophilic segment (PVDF-b-PDMAEMA) was successfully fabricated by iodine transfer polymerization. This strategy not only improved the PVDF membrane structure and hydrophilicity but also assisted in fouling resistance properties as an ultrafiltration membrane. The obtained PVDF/PVDF-b-PDMAEMA blend membrane displayed excellent water flux, which was enhanced 3 fold compared with that of the original membrane. The bovine serum albumin (BSA) rejection ratio (≥90%) was maintained at a reasonable level. Meanwhile, by incorporation of the amphiphilic block copolymer, the PVDF-based modified membrane possessed excellent protein resistance and high flux recovery ability. The blend membranes with high BSA separation efficiency and excellent antifouling properties will find promising applications in the field of separation science specifically in sewage purification.
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JOURNAL OF MEMBRANE SCIENCE
·
2018
·
IF 6.578
Jiuyun Cui,Zhiping Zhou,Atian Xie,Qianqian Wang,Siwei Liu,Jihui Lang,Chunxiang Li,Yongsheng Yan,Jiangdong Dai
Development of antifouling membrane to separate oil–water emulsions by low energy consumption approach is an urgent demand. Herein, we report for the first time a grass-like structured composite membrane from array growth of nickel cobalt layered double hydroxide (NiCo-LDH) onto the polydopamine modified polyvinylidene fluoride (PVDF) membrane surface via simple hydrothermal strategy. The surface morphology of as-prepared membrane has controlled by hydrothermal time. The obtained NiCo-LDH/PVDF composite membrane exhibits superhydrophilicity/underwater superoleophobicity for separating both surfactant-free and surfactant-stabilized oil–water emulsions by capillary effect under the driving of gravity. Moreover, with the advantages of antifouling performance, the membrane displays outstanding cyclic performance for long-term application, which is promising for practical oily wastewater treatment .
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危险品化学品经营许可证（带存储）