JOURNAL OF MEMBRANE SCIENCE
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2017
·
IF 6.035
Xiaobin Yang,Zhenxing Wang,Lu Shao
Oily wastewater and oil spills not only cause large amounts of resource wastefulness, but threaten water safety and human health. Besides, for some oily emulsions, the oil droplets are usually valuable, such as the soybean oil droplets formed during oil manufacture, and the oil droplets carrying high valued product from the extraction process or micro-emulsion reactor. Therefore, the collection and recovery of oil from water are particularly important. However, the recovery of oil droplets from emulsions and collection-lossless transportation of oil spills are still a big challenge, which cannot be solved by current oil/water separation methods, including the super-wetting strategy. Herein, we designed and prepared oil-unidirectional Janus membrane via unilateral decoration of commercial hydrophobic composite microfiltration membranes. The obtained Janus membrane is composed of a thin hydrophilic layer and thick hydrophobic supporting layer, and the asymmetric surface wettability can realize the unidirectional oil-transport property, viz. oil “diode”. Therefore, the obtained JMs with oil unidirectional transport property can realize the efficient collection and recovery of various oils. For example, the JM can effectively draw the micrometer-sized oil droplets from various oil-in-water emulsions, and realize the collection-lossless transportation of the oil spills. Our strategy can firmly stimulate and accelerate the advances of functional membranes toward the broad intelligent and sustainable usages.
研究领域:
材料科学
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环境科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Water Process Engineering
·
2022
·
IF 7.34
Lin Chen,Fangqing Li,Longjie Jiang,Fudong He,Yufei Wei
Polytetrafluoroethylene (PTFE) hydrophobic membranes used in direct contact membrane distillation (DCMD) processes were prone to fouling and wetting by oil and surfactants, which hampered their broad industrial application. In this work, a new Janus composite membrane was developed by modifying UiO-66-NH 2 with polyvinyl alcohol (PVA) as a cross-linking agent and immobilizing the modified UiO-66-NH 2 on the PTFE membrane by vacuum filtration. By tuning the ratio of PVA to MOF , an optimally proportioned Janus membrane was obtained, and its performance was tested in DCMD experiments through the use of a sodium chloride feed solution containing hexadecane and sodium dodecyl sulfate. The top layer of this Janus membrane exhibited underwater oleophobicity (130.1 ± 0.96°) and hydrophilicity in the air (54.0 ± 0.92°), while the bottom layer is hydrophobic (132.3 ± 0.97°). Compared to the pristine PTFE membrane, the modified Janus membrane demonstrated promising resistance to both membrane fouling and wetting of oils and surfactants. The desalination rate of 99.99% was still achieved within 24 h with the conductivity remaining lower than 10 μS/cm and the flux maintained at 21.3 L/(m 2 ·h). As a result, the Janus composite membrane developed in this study was shown to be a prospective alternative for treating wastewater containing oily substances and surfactants in a resourceful manner.
研究领域:
材料科学
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环境工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
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2018
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IF 6.578
Yanfei Liu,Tonghu Xiao,Chenghuan Bao,Yuhua Fu,Xing Yang
This study proposed to use the nonsolvent thermally induced phase separation (NTIPS) method to fabricate a novel Janus membrane for MD applications. The as-prepared dual-layer membrane consisted of a thin hydrophobic PVDF top-layer and a relatively thick hydrophilic PVDF-PVA sub-layer. By adopting a facile one-step co-casting technique and water soluble diluent ε-caprolactam (CPL), delamination-free dual-layer membrane was obtained. The SEM morphologies and FTIR crystalline analyses suggested the membrane formation mechanisms, where the hydrophobic top-layer was formed via NTIPS process, resulting in an ultra-thin dense skin with finger-like pores formed beneath; while the hydrophilic sub-layer was induced by TIPS, producing highly porous cellular structure with high degree pore interconnectivity. Combining the structural observation and MD performance results, suitable fabrication parameters were identified as a PVDF concentration of 15 wt% for the hydrophobic layer and coagulation temperature between 20 and 40 °C. The total membrane thickness was optimized as 100–150 µm, given the thickness of hydrophobic layer kept within an optimal range of 30–60 µm to ensure minimal mass transfer resistance. The Janus membrane exhibited stable salt rejection above 99.5% over continuous MD runs and superior permeation flux up to 165.3 kg m -2 h -1 at 80 °C, which was remarkably higher than reported MD membranes.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2018
·Vol. 7
·期 2
·632-638
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IF 9.931
Shenghua Zhou,Zhu Xiong,Fu Liu,Haibo Lin,Jianqiang Wang,Tiantian Li,Qiu Han,Qile Fang
Low energy consumption in water desalination is highly demanded. Herein, we show that the Janus porous membrane, which comprises a superhydrophobic SiO2 coating on a superhydrophilic polyvinylidene fluoride (PVDF) membrane, exhibits unprecedented osmotic water permeability (2.88 L m−2 h−1 bar−1) and near-complete reverse salt rejection (Js/Jw = 0.007 g L−1) far beyond the-state-of-art thin-film composite (TFC) membranes. The appropriate SiO2 seeding allows the hydrophilic PVDF fibrils to stretch out of the top tip of the microspheres to form a one-way valve, serving as nano-structured water channels while the superhydrophobic side, by trapping air, functions as the active layer to repel reverse salt diffusion. The hydrophilic microsphere partially covered by F-SiO2 is regarded as a micro-osmosis unit. Both external and internal concentration polarization are well diminished, with the superhydrophobic side facing towards the draw solution. This intriguing result deepens our understanding of unidirectional mass transfer through the Janus nano-channels in fluid osmosis.
研究领域:
材料科学
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环境工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
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2021
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IF 5.909
Wei Zhou,Cailong Zhou,Hao Yang,Jin Wang,Jingcheng Du,Li Chen,Huizhen Shen,Luxi Tan,Lichun Dong,Xinjuan Zeng
Traditional preparation methods of Janus membranes are either too complicated or cannot accurately control their characters such as surface wettability , layer thickness, and pore structure. Herein, asymmetric wettability and layer thickness on the copper mesh were successfully regulated by an interface-confined surface engineering strategy and applied for liquid manipulation. Water droplets can spontaneously infiltrate from the superhydrophobic side to the superhydrophilic side of the as-prepared Janus copper mesh (JCM), achieving unidirectional transportation. Besides, the separation efficiency of the JCM exceeds 99.2%, whether it is a combination of light or heavy oil-water mixtures. Moreover, compared to the corresponding superhydrophilic and superhydrophobic meshes, the JCM showed a 200% increase in fog collection. A fog collector with a sandwich structure was further developed, making up of a superhydrophilic inner layer and double-deck superhydrophobic external layers that always play a role of a Janus collector to allow a continuous and high-performance fog harvesting regardless of the direction of the fog flow. Overall, this work provides a new idea in the fabrication of Janus membranes, which could be extended to the transport of directional water, switchable oil/water separation, fog collection, and other fields.
研究领域:
材料科学
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环境科学
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表面工程学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
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2023
·
IF 6.1
Fangqing Li,Lin Chen,Yufei Wei,Zhiwei Yin,Keying Que
Membrane distillation (MD) is considered an emerging desalination technology. However, the presence of surfactants allows liquid to penetrate the membrane, resulting in membrane wetting, which hinders the commercialization of MD. In this study, we use very few modified materials to prepare novel Janus thin membranes that immobilize modified materials (graphene oxide (GO) and UiO-66-NH 2 ) on polytetrafluoroethylene (PTFE) hydrophobic base membranes via crosslinkers. The composite thin membrane properties with eight different ratios and contents of GO and UiO-66-NH 2 were fabricated and tested by a feed solution of sodium chloride containing a high concentration of sodium dodecyl sulfate. An optimal ratio of Janus membrane with high flux without affecting the effluent water quality was obtained. The Janus membrane exhibited excellent anti-wetting properties compared to the original PTFE membrane. A desalination rate of up to 99.9% was still available even under 48 h of long-term operating conditions by maintaining a flux of approximately 21.2 L/(m 2 ·h). The anti-wetting mechanism of this membrane was further confirmed by the modified XDLVO model. It suggested that the novel Janus membrane could be a highly promising substitute to the MD process for the resource-based treatment of surfactant-containing wastewater, which played an important role in promoting its application.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
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2023
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IF 9.5
Na Zhang,Jiaojiao Zhang,Xin Yang,Changxu Zhou,Xiaohui Zhu,Baicang Liu,Yue Chen,Shihong Lin,Zhining Wang
Membrane distillation (MD) is a promising technique for water reclamation from hypersaline wastewater. However, fouling and wetting of the hydrophobic membranes are two prominent challenges for the widespread application of MD. Herein, we developed an antiwetting and antifouling Janus membrane comprising a hydrogel-like polyvinyl alcohol/tannic acid (PVA/TA) top layer and a hydrophobic polytetrafluoroethylene (PTFE) membrane substrate via a facile and benign strategy combining mussel-amine co-deposition with the shrinkage–rehydration process. Interestingly, the vapor flux of the Janus membrane was not compromised, though a microscale PVA/TA layer was introduced, possibly due to the high water uptake and reduced water evaporation enthalpy of the hydrogel-like structure. Moreover, the PVA/TA-PTFE Janus membrane sustained stable MD performance while treating a challenging saline feed containing surfactants and mineral oils. The robust wetting resistance arises from the synergistic effects of the elevated liquid entry pressure (1.01 ± 0.02 MPa) of the membrane and the retardation of surfactant transport to the substrate PTFE layer. Meanwhile, the hydrogel-like PVA/TA layer hinders oil fouling due to its strongly hydrated state. Furthermore, the PVA/TA-PTFE membrane exhibited improved performance in purifying shale gas wastewater and landfill leachate. This study provides new insights into the facile design and fabrication of promising MD membranes for hypersaline wastewater treatment.
研究领域:
材料科学
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环境工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Energy Chemistry
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2023
·
IF 13.1
Hao Chen,Guangze Pan,Mei Yan,Fang Wang,Yadong Wu,Chongshen Guo
Low solar spectrum coverage, high evaporation enthalpy, and undesired salt deposition severely limited the solar-driven interfacial evaporation technology for further sewage purification and seawater desalination. To overcome these problems, we designed an amphiphilic Janus-structured polyaniline (PANI)/ZrC/cellulose acetate (CA) (J-PZCA) membrane. Firstly, the interfacial interaction between PANI and ZrC enhances the photoabsorption and photothermal conversion efficiency. Secondly, low thermal conductivity reduces the heat lost at the interface. Most importantly, ZrC could facilitate interfacial activation, which weakens the intermolecular forces of water by affecting the hydrogen bond. Under 1 solar irradiation (1 sun), the composite membrane exhibits a high evaporation rate of 1.31 kg m −2 h −1 and an excellent efficiency of 79.4%. In addition, the sewage purification and seawater desalination experiments reveal a remarkable purification capability of J-PZCA membrane. Especially for the treatment of high-concentration salt solution, it realizes a long-term stable evaporation performance due to the excellent salt deposition resistance. Therefore, the J-PZCA membrane constructed in this study provides a new perspective for the design of efficient interfacial evaporation devices.
研究领域:
材料科学
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环境科学
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能源科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Hyewon Jeon,Taehun Kim,Paula Jungwon Choi,Am Jang
With growing interest in hydrogen energy, liquid ammonia has emerged as a promising hydrogen carrier due to its low boiling point and high volumetric energy density. In addition to green and brown ammonia, white ammonia, produced through waste recycling, has gained attention. This study explored the use of a Janus membrane in a membrane contactor system for white ammonia recovery from high-strength wastewater, such as anaerobic digestion effluent, which is prone to membrane fouling owing to its complex organic and inorganic constituents. To address the challenge, a Janus membrane with asymmetric wettability, combining a hydrophilic surface and a superhydrophobic layer, was used to enhance interfacial stability and ammonia transport. The Janus membrane achieved a mass transfer coefficient (MTC) of 0.039 m/h, which was 8.3 % higher than that of the SHPO-only membrane and exhibited only a 5.13 % MTC reduction after extended fouling, compared to a 20.93 % reduction for the virgin membrane. Postoperative Fourier transform-infrared and X-ray photoelectron spectroscopy analyses confirmed the chemical integrity of both layers, and scanning electron microscopy imaging revealed limited surface deposition. In addition, the Janus configuration enabled directional vapor flow and reduced interfacial mass transfer resistance compared with symmetric membranes. The findings demonstrate that the Janus membrane provides a robust and scalable platform for stable ammonia separation in the presence of severe fouling and complex wastewater matrices.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2022
·
IF 4.889
Jietao Hu,Lishuang Gui,Mingning Zhu,Kuiliang Liu,Ya Chen,Xiaopan Wang,Jing Lin
Oil spills and oily wastewater discharged from industries and households have resulted in environmental and economic concerns. Therefore, emerging Janus membranes with anisotropic wettability have attracted significant attention as next-generation oil/water separation membranes owing to their specific, on-demand separation ability. However, the one-step separation of complex wastewater has not yet been achieved. Herein, a pH-responsive siloxane modified polystyrene microsphere/zinc oxide/carbon nanotube/polyvinylidene fluoride (S/PS/ZnO/CNTs/PVDF) membrane was rationally designed with Janus surfaces for providing hydrophilicity/underwater lipophobicity and lipophilicity/underoil hydrophobicity functionality. This study demonstrates that the underlying mechanism of on-demand separation of water-in-oil and oil-in-water emulsion is related to wettability, adhesive forces, and intrusion pressure. The proposed Janus membrane can achieve one-step separation of complex wastewater comprising oil, bacteria, organic dye, and metal ions. The effective removal of dyes is due to synergistic effects of electrostatic adsorption and photodegradation. This facile strategy for fabricating smart Janus separation membranes has application potential in on-demand oil/water separation and practical complex wastewater separation.
研究领域:
材料科学
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环境科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2019
·Vol. 7
·期 9
·4941-4949
·
IF 10.733
Weifeng Zhang,Xiangyu Li,Ruixiang Qu,Yanan Liu,Yen Wei,Lin Feng
Janus membranes with opposite wetting behavior on each side are of great significance in the oil/water separation field. However, most of the reported work only focuses on the separation of immiscible oil/water mixtures instead of emulsions. In addition, almost no previous work pays attention to whether the filtrate after the separation process can meet industrial emission standards. In order to achieve controllable stabilized emulsion separation with high efficiency, a polyaniline–silica nanoparticle (PANI–SiNP)-modified Janus membrane is prepared through a facile immersion-spray coating method. PANI polymer and SiNPs are modified on two sides of the substrate, just like Yin and Yang in Chinese Tai Chi, and have opposite but complementary properties. The PANI-coated surface is superhydrophilic with underwater superoleophobic wettability, which can separate oil-in-water emulsions (including different ionic types and crude oil-in-sea water emulsion) when it is facing up. Conversely, the SiNP-coated surface exhibits opposite wettability with superhydrophobicity and superoleophilicity, which can separate water-in-oil emulsions when this side is facing up. More importantly, this Janus material has high efficiency for both oil-in-water and water-in-oil emulsions, meeting the industrial emission and purification standards. The membrane shows excellent stability and recyclability, which means it can be applied in practical wastewater treatment.
研究领域:
材料科学
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环境工程
✓ 已验证
DOI
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.
研究领域:
材料科学
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环境工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）