JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
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2018
·Vol. 94
·期 2
·398-408
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IF 2.587
Chen Li,Lei Wang,Xudong Wang,Cuicui Li,Qibin Xu,Guangyuan Li
BACKGROUND Proton-exchange membrane (PEM) has a significant effect on the performance and overall cost of microbial fuel cells (MFCs). In this study, a novel composite PEM is fabricated by compositing sulfonated graphene oxide (SGO) with the Poly(vinylidene fluoride)-g-Poly(styrene sulfonic acid) (PVDF-g-PSSA) copolymer. The performance of MFCs with these newly prepared composite PEMs as separators was evaluated. A Quartz crystal microbalance with dissipation (QCM-D) combined with membrane-coated sensor crystals was used to investigate the biofouling mechanism of PEMs in MFCs at a micro-perspective. RESULTS The successful sulfonation of GO was confirmed by Fourier transform infrared spectrometry and X-ray photoelectron spectroscopy. When the SGO loading was 1.0 wt%, the SGO/PVDF-g-PSSA membrane had higher water uptake (32.56%), proton conductivity (0.083 S cm −1 ) and excellent hydrophilicity (contact angle 70.78°) than that of Nafion 117. QCM-D results further confirmed its better anti-fouling property vs that of the PVDF-g-PSSA, GO/PVDF-g-PSSA, and Nafion 117 membranes. Moreover, the MFC working with the SGO/PVDF-g-PSSA membrane exhibited the highest maximum power density and best stability of power production after 3 months of operation. CONCLUSION The SGO/PVDF-g-PSSA-1.0 composite PEM can be used as an alternative material to Nafion in MFCs and is conducive to the long-term stable operation of MFCs. © 2018 Society of Chemical Industry
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高影响因子
JOURNAL OF MEMBRANE SCIENCE
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2019
·
IF 7.015
Xipeng Li,Huiting Shan,Min Cao,Baoan Li
Omniphobic membranes have been brought to great attention recently regarding the ability to resist both water and low surface tension liquids, thus can be utilized for desalination of saline wastewater containing low surface tension contaminants in membrane distillation (MD). In this study, a facile, environment-friendly, and one-step strategy is developed for fabricating an omniphobic membrane with re-entrant structure and low surface energy by spraying a waterborne coating solution comprising of fluorocarbon surfactant (FS, Zonyl@8867L), fluorinated alkyl silane (FAS), and silicon dioxide nano-particles (SiO 2 NPs) onto amino functionalized polyvinylidene difluoride (PVDF) membrane via electrostatic adsorption. As a result, the prepared omniphobic FS/FAS/Si membrane possesses high liquid repellency to water, diiodomethane, mineral oil-in-water emulsion (0.10 % v/v), mineral oil, and SDS solution (0.40 mM) with the contact angle of 164.40 ± 0.95°, 159.12 ± 3.12°, 154.31 ± 3.71°, 153.31 ± 2.09°, and 157.14 ± 3.29°, respectively. Compared to the original PVDF membrane, the omniphobic FS/FAS/Si membrane displays higher rejection (about 99.99%) and superior anti-wetting and anti-fouling characteristics even to the saline feed solution with surfactants, oil pollutants, or hydrophilic organic pollutants in MD process. The results mentioned above verify that the obtained omniphobic FS/FAS/Si membrane has potential application for the desalination of the high saline wastewater containing low surface tension contaminants.
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International Journal of Environmental Research
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2024
·Vol. 19
·期 1
·1-13
·
IF 2.6
Liu Liao,Ren Chunji,Zhang Wuhuan,Fan Meikun,Zhang Jianqiang
The printing and dyeing wastewater has high chromaticity, biorefractory properties, and significant toxicity. In this study, PVDF-PVA/GO was synthesized for dyes’ adsorption with various chemical properties. Incorporating graphene oxide (GO) into the composite substantially enhanced the hydrophilicity and electronegativity of the PVDF membrane. Results indicated that the adsorption efficiencies for rhodamine B (RhB) and methylene blue (MB) are higher than those of methyl orange (MO) and bromocresol green (BCG). At an initial pH of 8, the maximum adsorption capacities for RhB and MB were 11.81 and 9.25 mg/g, respectively, while MO and BCG indicated considerably lower capacities of 0.59 and 0.63 mg/g, respectively. The cyclic utilization of the PVDF-PVA/GO revealed minimal degradation in adsorption efficiency. The adsorption kinetics of the four dyes primarily follow intra-particle diffusion mechanisms, resulting in the binding of dye molecules to the PVDF-PVA/GO membrane through electrostatic interactions. Notably, competitive adsorption phenomena were observed in mixed dye systems, especially between RhB and MB. Comparative analyses indicated an increased adsorption capacity for MB in the mixed dye system, accompanied by a notable reduction in the adsorption capacity of RhB. This study provides a theoretical foundation for the remediation of printing and dyeing wastewater. Graphical abstract
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Journal of Inorganic and Organometallic Polymers and Materials
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2024
·
IF 3.9
Yang Jie,Yan Zhuo,Dai Jiangdong
With the rapid industrial development worldwide, the volume of oily wastewater, including petroleum spills and industrial effluents, has increased dramatically, posing a threat to ecosystems and human health. Membrane separation technology, known for its advantages of phase-transition-free operation, low energy consumption, and simplicity, has gained rapid popularity in wastewater treatment. This study focused on modifying PVDF membranes using PVA-TA hydrogels with two distinct coordination strategies: TA-Fe 3+ coordination and APTMS covalent cross-linking. The resulting composite membranes exhibited superhydrophilic/underwater superoleophobic properties with high emulsion flux (3800–6900 and 4200–12,000 Lm − 2 h − 1 bar − 1 ) and separation efficiency (> 98.9% and > 99.3%) for various oil-water emulsions. Notably, the stability of the hydrogel network allowed the composite membranes to maintain elevated fluxes (6847.2 and 10266.7 Lm − 2 h − 1 bar − 1 ) and separation efficiencies (97.8% and 99.3%) even after 10 cycles for dichloroethylene-water emulsion. The addition of Fe 3+ and APTMS enhances hydrogel stability and roughness, with APTMS contributing to superior wetting and separation performance. This work provides valuable insights into the impact of different coordination mechanisms on hydrogel-coated membranes, offering a foundation for the development of advanced materials in efficient oil-water separation.
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JOURNAL OF MATERIALS CHEMISTRY
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2012
·Vol. 22
·期 18
·9131-9137
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IF 5.968
Mimi Tao,Fu Liu,Lixin Xue
A method of obtaining a hydrophilic and antifouling poly(vinylidene fluoride) (PVDF) membrane is developed via in situ polymerisation of 2-hydroxyethyl methacrylate (HEMA) in PVDF solution and subsequent micro-phase separation. The immobilization of PHEMA in a PVDF membrane was verified by Fourier Transform Infrared Spectroscopy (FTIR) and 1H Nuclear Magnetic Resonance Spectroscopy (1H-NMR). X-ray Photoelectron Spectroscopy (XPS) studies further unveiled the enrichment of PHEMA on the PVDF membrane surfaces. Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) images revealed that the modified membrane had a fibrous-like microstructure in the cross section and a porous top surface. Water contact angle measurement suggested that the modified membrane formed by in situ polymerisation and micro-phase separation possessed higher hydrophilicity than the control membrane formed by blending PVDF and pre-polymerised PHEMA. The protein fouling of the modified membrane was considerably alleviated and the dried membrane showed spontaneous wettability and excellent permeability. Based on Wide-Angle X-ray Diffraction (WAXD) and the above results, a possible membrane formation mechanism for the in situ polymerisation and subsequent micro-phase separation was proposed.
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INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2024
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IF 3.8
Jiong Li,Guoyong Du,Chunping Deng,Huatao Zhang,Lijuan Dai
In recent years, modified membranes for oil–water separation have garnered significant attention. However, the complexity of the process, low efficiency, and serious oil contamination have been the main obstacles to its application. Hence, there is an urgent need to explore simple, environmentally friendly modification methods. Inspired by adhesive bioproteins and diatomaceous silica, this study presents a simple, low-cost, and environmentally friendly biomimetic coating strategy to prepare a highly efficient oil–water separation membrane with convenient separation and excellent resistance to oil fouling. Using pyrogallic acid (PG) and silane coupling agent KH550, a one-step modification of the poly(vinylidene fluoride) (PVDF) microfiltration membrane (MF) was conducted, transitioning the surface wettability of the PVDF membrane from highly hydrophobic to superhydrophilic. This resulted in layered nanoscale papillary structures on the PVDF–MF surface, imparting superhydrophilicity and underwater superoleophobicity, along with excellent oil–water separation capability. Under a transmembrane pressure of 0.85 bar, systematic testing of the modified membrane demonstrated that the stable flux of the emulsion is approximately 950 L m–2 h–1, with an oil rejection rate exceeding 99% and significantly improved fouling resistance, as well as excellent chemical stability and salt resistance. The “green” in situ biomimetic silicification strategy is equally applicable to inert materials such as polytetrafluoroethylene (PTFE) membranes, demonstrating its significant potential for application on other materials.
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RSC Advances
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2016
·Vol. 6
·期 67
·62186-62192
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IF 3.289
Jianjian Cai,Shouyong Zhou,Yijiang Zhao,Ailian Xue,Yan Zhang,Meisheng Li,Weihong Xing
The hydrophilicity of a thermo-responsive PVDF/palygorskite-g-PNIPAAM hybrid ultrafiltration membrane was enhanced via surface segregation induced by coagulation bath temperature (CBT). The N1s content of the hybrid ultrafiltration membranes prepared at 5 and 20 °C is 1.77% and 1.02%, respectively while that of the membrane prepared at 40 °C is just 0.73%. This indicated that the PNIPAAM chains could be dragged to the membrane surfaces or pores via surface segregation induced by temperature. This resulted in higher hydrophilicity and permeability as well as thermo-responsiveness for membranes prepared at lower temperatures. The initial water contact angle of the PVDF/palygorskite-g-PNIPAAM hybrid ultrafiltration membrane prepared at 5 and 20 °C is 75.2° and 75°, respectively, which is about 6° lower than the one prepared at 40 °C. A higher pure water flux (PWF) of about 366 L m−2 h−1 at 40 °C was obtained for the hybrid membrane prepared at 5 °C while the one prepared at 40 °C only reached 274 L m−2 h−1. Meanwhile, membranes prepared at low temperature exhibited fewer macrovoids, lower membrane thickness and larger elongation.
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JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
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2017
·Vol. 28
·期 18
·13360-13370
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IF 2.019
Lu Haowei,Lin Jiaqi,Yang Wenlong,Liu Lizhu
The Ba 0.859 Ca 0.141 Zr 0.106 Ti 0.894 (BCZT) nano-particles were modified by polyimide (PI) through a chemical coating method. And the PI@BCZT/polyvinylidene fluoride (PVDF) flexible composite films were fabricated by solution casting method. The transmission electron microscopy and scanning electron microscopy results show that the nano-particles is about 50 nm, PI is uniformly coated on the surface of BCZT nano-particles about 7–10 nm as well as there are uniform and improved dispersion in the matrix after modification. A series of dielectric properties were carried out. The results show the 50 vol% composites own a remarkably enhanced dielectric permittivity (ε r = 130) at 100 Hz. After modification, the breakdown strength has increased from 20 to 96 kV mm −1 and the loss tangent is reduced from 1.8 to 0.2 at 100 Hz compare with un-modified composites in 40 vol% dopant. With the increase of dopant, ferroelectricity of composites can be enhanced. The optimal residual polarization is 40 vol% PI@BCZT composites, which possess 1.025 μC/cm 2 under 50 kV/mm external electric field. In addition, after modification, thermo-gravimetric analysis exhibits the degradation temperature Td 5% and Td 10% of PI@BCZT/PVDF composites can be enhanced about 5–10 °C and show better thermal stability than un-modified composites.
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SEPARATION AND PURIFICATION TECHNOLOGY
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2024
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IF 8.1
Guijing Chen,Songzhe Li,Xifan Li,Xin Li,Baicang Liu
The collection and reuse of roof rainwater can alleviate water shortage for daily life. In this study, polyvinylidene fluoride hollow fiber membranes tuned with three multi-walled carbon nanotubes (pure MWCNTs, MWCNTs-COOH, and MWCNTs-OH) were prepared using a non-solvent induced phase separation method for gravity-driven membrane filtration to purify roof rainwater. The results showed that the MWCNTs were distributed on the membrane surface and throughout the porous structure of the cross-section, which changed the pore structure parameters and hydrophilicity. The pure water flux of the MWCNTs tuned membranes increased by 152.5 % at 1.0 bar, and the rejection rates of humic acid and bovine serum albumin increased from 97.4 % and 75.7 % to 98.9 % and 96.3 %, respectively. The extended Derjaguin, Landau, Verwey, and Overbeek (xDLVO) theory states that the presence of MWCNTs leads to changes in the physicochemical properties of the membrane surface, resulting in membranes with different anti-fouling behaviors. A gravity-driven membrane filtration test was continuously operated for 100 days, and all membranes removed 25.0–26.7 %, 49.5–53.0 %, and 89.0–93.3 % of total dissolved solids, dissolved organic carbon, and turbidity from roof rainwater, respectively. However, the pure MWCNTs modified membrane with relatively hydrophobic properties showed a 12.4 % increase in flux over the unmodified membrane. Importantly, the presence of the MWCNTs in the membrane changed the microbial diversity in the biofilter cake layer.
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ADVANCED FUNCTIONAL MATERIALS
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2024
·
IF 18.5
Mengmeng Chen,Neng Hu,Weijia Wang,Lin Lei,Huiqing Fan,Peter Müller-Buschbaum,Qi Zhong
Inspired from seaweed swayed by waves, the enhanced hydrogen evolution is realized in porous and hybrid g-C 3 N 4 /Pt-PVDF electrospun membranes via piezoelectricity from water flow energy. The membranes are fabricated by dispersing g-C 3 N 4 /Pt into the mixed solution of PVDF and PEO, followed by electrospinning and selective removal of PEO. By changing the PEO amount, the pore size in nanofibers is adjusted. Due to the hydrogen bonding between g-C 3 N 4 /Pt and PVDF, the β phase of PVDF is increased, beneficial for the piezoelectricity performance. When the electrospun membranes are exposed to water flow, an additional potential field is triggered due to the deformation of PVDF. It not only eases the photogeneration of charge carriers from g-C 3 N 4 /Pt but also hinders their recombination. The prolonged lifetime significantly improves the photocatalytic water splitting of g-C 3 N 4 /Pt under visible light. The hydrogen evolution in the electrospun membranes (PVDF to PEO = 4:1) is profoundly improved to 9 278 µmol h −1 g −1 , almost doubled to the pure g-C 3 N 4 /Pt nanosheets (5 220 µmol h −1 g −1 ). Therefore, the seaweed-inspired electrospun membrane is a promising strategy for the efficiently photocatalytic water splitting via g-C 3 N 4 in an aqueous environment, such as a natural sea and lake, by the piezoelectricity gained from the water flow energy.
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Polymers
·
2024
·Vol. 16
·期 13
·1781
·
IF 4.7
Arsalan Ahmed,Nazakat Ali Khoso,Muhammad Fahad Arain,Imran Ahmad Khan,Kashif Javed,Asfandyar Khan,Sanam Irum Memon,Qinguo Fan,Jianzhong Shao
The demand for self-powered, flexible, and wearable electronic devices has been increasing in recent years for physiological and biomedical applications in real-time detection due to their higher flexibility and stretchability. This work fabricated a highly sensitive, self-powered wearable microdevice with Poly-Vinylidene Fluoride-Tetra Fluoroethylene (PVDF-TrFE) nano-fibers using an electrospinning technique. The dielectric response of the polymer was improved by incorporating the reduced-graphene-oxide (rGO) multi-walled carbon nano-tubes (MWCNTs) through doping. The dielectric behavior and piezoelectric effect were improved through the stretching and orientation of polymeric chains. The outermost layer was attained by chemical vapor deposition (CVD) of conductive polymer poly (3,4-ethylenedioxythiophene) to enhance the electrical conductivity and sensitivity. The hetero-structured nano-composite comprises PVDF-TrFE doped with rGO-MWCNTs over poly (3,4-ethylenedioxythiophene) (PEDOT), forming continuous self-assembly. The piezoelectric pressure sensor is capable of detecting human physiological vital signs. The pressure sensor exhibits a high-pressure sensitivity of 19.09 kPa−1, over a sensing range of 1.0 Pa to 25 kPa, and excellent cycling stability of 10,000 cycles. The study reveals that the piezoelectric pressure sensor has superior sensing performance and is capable of monitoring human vital signs, including heartbeat and wrist pulse, masticatory movement, voice recognition, and eye blinking signals. The research work demonstrates that the device could potentially eliminate metallic sensors and be used for early disease diagnosis in biomedical and personal healthcare applications.
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PubMed
高影响因子
JOURNAL OF MEMBRANE SCIENCE
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2024
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IF 8.4
Qichao Ding,Kedi Dong,Xinyu Si,Tonghu Xiao,Xing Yang
Amphiphobic membranes have attracted much attention in membrane distillation (MD) applications, due to its potential in simultaneously resisting membrane wetting and fouling when treating complex wastewater. The current amphiphobic membranes often require non-trivial design of multilevel re-entrant structure. Here we proposed a new class of amphiphobic membranes without multilevel re-entrant surface, by creating a composite poly(vinylidene fluoride)/polyvinyl alcohol/SiO 2 membrane with asymmetric structure and well-controlled small surface pores via the NTIPS method, followed by direct fluorination via chemically binding the –OH of polyvinyl alcohol and low surface energy moieties 1H,1H,2H,2H-perfluorodecyl-triethoxysilane, assisted by 3-aminopropyltriethoxysilane and trimesoyl chloride. The amphiphobic membrane showed superior liquid entry pressure above 5 bar with various simulated saline feeds containing surfactants and organic pollutants. The amphiphobic membrane demonstrated robust anti-wetting and anti-fouling performance through a series of 24-h direct contact MD experiments using the above feeds, presenting stable water flux and high rejection, e.g., flux of 50.6 kg/(m 2 ·h) and rejection >99.9 % with feed containing 3.5 wt% NaCl, 1 mM FA, and 2 mM SDS. The results demonstrated the fabrication of robust amphiphobic membrane through simple procedure utilizing the synergy between pore structure and surface chemistry, inspiring more efforts to design adequate membranes for treating complex wastewater.
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