CHEMOSPHERE
·
2022
·
IF 8.943
Xiaoju Yan,Chengyu Yang,Cong Ma,Hui Tao,Shirong Cheng,Lin Chen,Guodong Wang,Xinping Lin,Chengzhi Yao
Membrane fouling and wetting limit the applications of membrane distillation (MD) for wastewater treatment , especially when treating the wastewater with a high concentration of low surface tension substances such as oil and surfactants. In this paper, virgin polyvinylidene fluoride (PVDF) membrane was modified by polydimethylsiloxane (PDMS) to enhance anti-wetting ability. Then a thin polydopamine (PDA) layer was coated as a reaction platform for further modification. Polyethyleneimine (PEI) was cross-linked with PDA to form a uniform and stable layer, through hydrogen bonds and electrostatic interaction to immobilize hydrophilic MXene, which formed a Janus MXene-PVDF membrane. The MXene layer was the key for superoleophobicity and high liquid entry pressure (LEP) of membrane, capable of mitigating membrane fouling and wetting when dealing with low surface tension wastewater (LSTW). From the experiments results, pristine PVDF membrane showed severe fouling and wetting with flux decline and salt leakage during treatment of LSTW (surfactants containing water, oil-in-water emulsion and sodium dodecyl sulfate stabilized oil-in-water emulsion). However, under the same conditions, the Janus MXene-PVDF membrane exhibited remarkably stable flux (9.3 kg m −2 h −1 , 9.1 kg m −2 h −1 , 10.2 kg m −2 h −1 ) and salt rejection (almost 99.9%) after 15 h operation. Excellent fouling and wetting resistance of MXene-PVDF membrane was mainly attributed to its superhydrophilic and superoleophobic top surface (in-air water contact angle: 30.2°, under-water oil contact angle: 169.9°) and hydrophobic substrate (in-air water contact angle: 130.8°), together with high LEP value (91.1 Kpa). This study provides a viable route to fabricated a Janus membrane with outstanding fouling and wetting resistance for LSTW, oily wastewater and it has great potential for sewage treatment in the future.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2021
·
IF 9.028
Yuanmiaoliang Chen,Kang-Jia Lu,Wenxiao Gai,Tai-Shung Chung
Membranes with robust antiwetting and antifouling properties are highly desirable for membrane distillation (MD) of wastewater. Herein, we have proposed and demonstrated a highly effective method to mitigate wetting and fouling by designing nanofiltration (NF)-inspired Janus membranes for MD applications. The NF-inspired Janus membrane (referred to as PVDF-P-CQD) consists of a hydrophobic polyvinylidene fluoride (PVDF) membrane and a thin polydopamine/polyethylenimine (PDA/PEI) layer grafted by sodium-functionalized carbon quantum dots (Na+-CQDs) to improve its hydrophilicity. The vapor flux data have confirmed that the hydrophilic layer does not add extra resistance to water vapor transport. The PVDF-P-CQD membrane exhibits excellent resistance toward both surfactant-induced wetting and oil-induced fouling in direct contact MD (DCMD) experiments. The impressive performance arises from the fact that the nanoscale pore sizes of the PDA/PEI layer would reject surfactant molecules by size exclusion and lower the propensity of surfactant-induced wetting, while the high surface hydrophilicity resulted from Na+-CQDs would induce a robust hydration layer to prevent oil from attachment. Therefore, this study may provide useful insights and strategies to design novel membranes for next-generation MD desalination with minimal wetting and fouling propensity.
研究领域:
材料科学
·
环境工程
✓ 已验证
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2025
·
IF 9
Haiyun Li,Zhengshi Yu,Yibo Lin,Wentian Zhang,Cunxian Lai,Lichao Xia,Fangang Meng,Shanshan Zhao
Membrane distillation (MD) is a promising technology for hypersaline wastewater treatment. However, commercial hydrophobic MD membrane usually suffers from severe wetting/fouling/scaling challenges that seriously hinder its wide applications. It is urgent to develop a robust MD membrane with simultaneous wetting/fouling/scaling resistance in a facile way. In this study, a Janus membrane with a dense hydrophilic nanofiltration top layer was simply fabricated by co-deposition of pyrogallic and polyethylenimine on hydrophobic polyvinylidene difluoride membrane followed by glutaraldehyde cross-linking. The Janus membrane can maintain stable performance during long-term treatment of saline wastewater containing surfactants, oil, and/or mineral ions, suggesting its excellent simultaneous wetting/fouling/scaling resistance. The mechanisms analyses reveal that the excellent wetting/fouling resistance is owed to the combined effects of strong surface hydration barrier, size exclusion, and strong capillary force. Moreover, the positively charged amino groups on the membrane surface further enhance the scaling resistance. Remarkably, the Janus membrane demonstrated exceptional performance during long-term (>100 h) treatment of ethylene waste lye, a hypersaline organic wastewater containing a broad spectrum of contaminants. The membrane possessed stable vapor flux and exhibited near-perfect salt rejection (99 %) and organic rejection (98 %). Our study provides a simple method for designing a robust Janus membrane for treating hypersaline organic wastewater and demonstrates the significant industrial application potential of MD technology.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
DESALINATION
·
2023
·
IF 9.9
Cheng Lei,Jinlong Han,Tengyu Cui,Weifeng Cao,Yinhua Wan,Haoli Zhou,Fei Shen
Conventional membrane distillation (MD) membranes are hydrophobic and challenged by severe membrane fouling and wetting. Current surface modification strategies for anti-fouling and anti-wetting purposes, usually complex and time-consuming, often compromise the MD flux. Herein, we propose a modified interfacial polymerization (mIP) approach to fabricate Janus membranes with rapid and robust MD performance. In the mIP process, a dry hydrophobic substrate is first immersed in an oil-phase monomer solution and then in contact with an aqueous monomer solution to trigger the mIP reaction. The as-fabricated Janus membrane (e.g., IP 2 @PTFE) comprised an ultrathin, underwater oleophobic, and defect-free polyamide (PA) layer and a porous polytetrafluoroethylene (PTFE) substrate. Compared with the unmodified PTFE membrane, the vacuum MD flux of the IP 2 @PTFE membrane held a 177.4 % increase when tackling a NaCl solution (3.5 wt%) at 60 °C. When the NaCl solution contained sodium dodecyl sulfate (SDS) surfactant or/and mineral oil, the IP 2 @PTFE membrane exhibited fouling and wetting resistance simultaneously; conversely, severe oil fouling and quick SDS-induced wetting occurred on the pristine PTFE membrane. The mIP process does not require any pretreatment of the hydrophobic substrate, so it is facile and scalable. We believe that this study will facilitate the design of robust MD membranes.
研究领域:
材料科学
·
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2022
·
IF 10.53
Dejun Feng,Xianhui Li,Zhangxin Wang
Membrane wetting, fouling, and scaling are three prominent challenges that limit membrane distillation (MD) applications. To overcome these challenges, novel MD membranes including omniphobic membranes and Janus membranes with a dense hydrophilic surface layer have been developed. In this study, we fabricated an omniphobic membrane and a Janus membrane composed of a dense polyvinyl alcohol (PVA) surface layer and a polyvinylidene fluoride (PVDF) substrate. The two membranes have been compared in MD experiments with different feeds. Furthermore, the working mechanisms of the two membranes have been elucidated. As a result, neither the omniphobic MD membrane nor the Janus MD membrane can resolve all three challenges at the same time. Specifically, both the omniphobic MD membrane and Janus MD membrane can resist wetting but via different working mechanisms. From breakthrough pressure (BP) determinations with an ethanol-water mixture (i.e., a low-surface-tension liquid), the omniphobic MD membrane resists wetting as its LEP (82.0 ± 9.2 kPa) is larger than the transmembrane pressure in the MD operation, while the Janus MD membrane resists wetting because the huge capillary pressure (550 ± 50 kPa) in the dense hydrophilic surface layer retains the wetting solution. The omniphobic MD membrane is prone to oil fouling because of the strong underwater hydrophobic attraction between the membrane surface and the mineral oil droplets, while the Janus MD membrane can substantially mitigate fouling due to the lack of attraction between the mineral oil droplets and the hydrophilic membrane surface. The omniphobic MD membrane exhibits outstanding scaling resistance because minerals can hardly precipitate and/or crystalize on the membrane surface, while the Janus MD membrane was susceptible to scaling due to the precipitation and/or crystallization of minerals inside the hydrophilic surface layer. Therefore, the selection of MD membranes should depend on the feed constituents. Overall, our study provides important guidelines for the future development of robust MD membranes.
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
·
IF 8.6
Wei Zhang,Shuili Yu,Ping Li,Xingli Ji,Rongsheng Ning,Pan Li
In this study, we developed novel Janus membranes with multilevel hierarchical structures to prevent membrane pore wetting and enhance the performance for desalination simultaneously. Here, a Janus membrane with multilevel roughness was tailored via a polydopamine (PDA) coating followed by deposition of Fe 3 O 4 nanoparticles and PDA sealing. These novel Janus membranes demonstrated outstanding antiwetting properties and salt rejection performances in comparison to pristine polytetrafluoroethylene (PTFE) membrane. Particularly, the specific flux of Janus membranes was maintained in a relatively stable state (0.6–0.7) after membrane cleaning with pure water, meanwhile, the permeate conductivity was maintained in the range of 0–30 µS/cm with the desalination rate of 99.9% during the vacuum membrane distillation (VMD) tests by using 6.98 wt.% feed solutions, indicating that these Janus membranes (i.e., P/Fe/P-PTFE membrane) can improve the performance for VMD desalination without membrane wetting throughout the test duration. Furthermore, we ascribed these Janus membranes’ superior performances to the coupled effects of super hydrophilicity brought about by PDA layer and self-healing mechanism provided by Fe 3 O 4 nanoparticles. This work highlights the great potential of novel Janus membranes with multilevel hierarchical structures for water reclamation from challenging high-salinity wastewater through VMD.
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2023
·
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
·
环境工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
·
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
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
DESALINATION
·
2023
·
IF 9.9
Anqi Wang,Wei Chen,Xiaomeng Lan,Mingmei Ding
To alleviate global water scarcity , membrane distillation (MD) has been identified as a promising technology for desalination . However, there exists a trade-off effect between membrane permeability and anti-wetting performance, impeding the intensive application of MD. To address this problem, inspired by the ion-sieving effect and the special nanostructure of aquaporins to break the trade-off between permeability and selectivity , a porous MXene coating layer with heterostructural channels in fusiform shape was designed on a PVDF membrane through a hydrazine-induced approach. The coating layer was in a foam shape with hydrophobic surfaces and outstanding stability in water. The delicate-designed fusiform channels endowed the membrane with enhanced permeability (the average flux of the optimum modified membrane was 55.59 kg/m 2 h with a temperature gradient of 60 °C (feed temperature: 70 °C and permeate temperature: 10 °C) and flow velocity of 400 ml/min, nearly 2.5 times as high as that of the virgin membrane) and resistance to simultaneous sault induced and foulant-induced wetting performance. This paper proposed a novel strategy for engineering porous nanostructures with dual-spacing channels on the membrane surface to ensure high permeability and stable excellent desalination performance.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Mohammed Karama Alsebaeai,Abdul Latif Ahmad,Boon Seng Ooi
In this research, the construction of a highly wetting-resistance membrane surface was achieved through an integrated dip-coating phase inversion process to accelerate water mass transfer of membrane distillation (MD). The synergistic effect of incorporating reduced graphene oxide (rGO) embedded Poly (vinylidene fluoride- co -hexafluoropropylene) (PVDF-HFP) on the surface of a PVDF hollow fiber support membrane using a dilute coating solution was studied. Various loadings of rGO nanosheets were incorporated into the dilute PVDF-HFP coating to systematically investigate its physicochemical characteristics, including surface morphology, hydrophobicity and wetting resistance which could be analyzed using scanning electron microscopy (SEM), atomic force microscopes (AFM), water contact angle (WCA), porosity measurement, pore size, x-ray diffraction (XRD), and liquid entry pressure (LEP) tests. The membrane separation performance for desalination was evaluated using direct contact membrane distillation (DCMD) process. Compared to the PVDF hollow fiber support membrane, the rGO-embedded PVDF-HFP coating layer demonstrates outstanding enhancements. The membrane surface exhibits enhanced hydrophobicity, as evidenced by an increased WCA from 105.37° (for the PVDF support membrane) to 148.37° (for the rGO/PVDF-HFP composite membrane). Additionally, the water permeability significantly improved, achieving a water flux of 25.9 kg m -2 h -1 (compared to 11.55 kg m -2 h -1 for the PVDF support membrane). These enhancements occur without compromising NaCl rejection, which remains consistently above 99.99 % (3.5 wt% NaCl aqueous solution at a feed temperature of 70 °C and a permeate temperature of 18 °C). These findings underscore the potential of rGO/PVDF-HFP in enhancing MD performance. The composite HF membrane demonstrates remarkable stability during continuous MD operation over a 48 h period. Pore wetting is effectively avoided, indicating that the composite membrane has superior resistance to wetting and excellent stability.
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
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
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2022
·
IF 4.326
Yurong Zhao,Xing Xing,Congbin Xu,Yali He,Chen Yang,Jianzhong Zheng,Zhiqiang Hu
Maintaining hydrophobicity of the membrane in membrane distillation is vital for treating high-salinity feedwater containing surface active substances due to their wetting impact on the membrane. An effective approach to mitigate membrane wetting is to build rough nanostructures on a pristine membrane to render its surface omniphobic. Directly building nanostructures on polypropylene (PP), however, is challenging, as the material is chemically inert. In this study, a novel method was developed to physically plant ZnO seeds on the PP membrane above the material’s heat deflection temperature. A biomimetic nanostructure was then constructed on the membrane surface by growing fluorinated ZnO nanorods along the seeded PP substrate. The resulting omniphobic membrane exhibited a contact angle constantly above 160° against a test solution containing 50 g/L NaCl and 0.06 mM sodium dodecyl benzenesulfonate. Compared to the pristine PP membrane, the modified PP membrane showed a nearly complete salt rejection and much improved antiwetting capacity against the surfactant added in the test solution. The physical seeding method presented in this study is therefore a promising alternative approach to functionalize chemically inert polymeric substrates with constructed biomimetic nanostructures.
研究领域:
材料科学
·
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）