Membranes
·
2023
·Vol. 13
·期 2
·225
·
IF 4.2
Yubo Xu,Long-Fei Ren,Jun Li,Chengyi Wang,Yangbo Qiu,Jiahui Shao,Yiliang He
Membrane distillation (MD) is attractive for water reclamation due to the fact of its unique characteristics. However, membrane wetting becomes an obstacle to its further application. In this paper, a novel hydrophobic polyvinylidene fluoride/poly(vinyl pyrrolidone) (PVDF/PVP) membrane was fabricated by electrospinning and solvothermal treatment. The electrospun membranes prepared by electrospinning showed a multilevel interconnected nanofibrous structure. Then, a solvothermal treatment introduced the micro/nanostructure to the membrane with high roughness (Ra= 598 nm), thereby the water contact angle of the membrane increased to 158.3 ± 2.2°. Owing to the superior hydrophobicity, the membrane presented high resistance to wetting in both NaCl and SDS solutions. Compared to the pristine PVDF membrane, which showed wetting with a flux decline (120 min for 0.05 mM surfactant solution treatment), the prepared membrane showed outstanding stability over 600 min, even in 0.2 mM surfactant solutions. These results confirm a simple method for anti-wetting hydrophobic membrane preparation, which presented universal significance to direct contact membrane distillation (DCMD) for industrial application.Keywords:membrane distillation;membrane wetting;electrospinning;solvothermal 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 MEMBRANE SCIENCE
·
2024
·
IF 8.4
Jiaojiao Zhang,Xin Yang,Na Zhang,Zhimin Tao,Linxin Han,Bing Wei,Ruiyao Qi,Yunke Fu,Zhining Wang
Thermally driven membrane distillation (MD) has garnered significant attention in hypersaline solution treatment. However, MD membranes suffer from inevitable membrane fouling and wetting owing to its inherent hydrophobicity and the complex composition of wastewater. Herein, dense polyamide (PA) Janus membranes based on both polyvinyl alcohol (PVA) and aramid nanofiber (ANF) intermediate layers are fabricated atop the hydrophobic polytetrafluoroethylene (PTFE) substrate via a coating-assisted interfacial polymerization (IP) method. The PVA and ANF hydrophilic coatings provide a favorable interface condition for the IP process to facilitate the introduction of a complete and dense PA layer. While treating the oily saline feed, both PA Janus membranes can significantly resist fouling owing to hydrophilic PA composite layers. When treating saline feed containing a high sodium dodecyl sulfate (SDS) surfactant, the PA/PVA PTFE membrane might experience progressive wetting with a prolonged operation time caused by SDS penetrating through the PA/PVA composite layer, while the PA/ANF PTFE membrane exhibits robust wetting resistance. Benefiting from ANF coating with superior swelling resistance and thermal stability conducive to maintain a denser and more complete PA layer compare to PVA coating, the PA/ANF PTFE membrane simultaneously resists wetting and fouling when dealing with a complex saline solution containing both oil and SDS surfactant, which is confirmed by its stable flux and low permeate conductivity in the continuous MD operation for 100 h. Scalable fabrication process and robust performance of the composite membrane endow it with great potential in saline wastewater desalination practicability.
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
JOURNAL OF MEMBRANE SCIENCE
·
2023
·
IF 9.5
Wenting Zhou,Yuanmiaoliang Chen,Xiaojia He,Zhangxin Wang
Membrane wetting is an inevitable challenge in membrane distillation (MD). To overcome this challenge, a few dewetting techniques have been developed, but the reversibility of membrane wetting induced by various contaminants has not been well understood. Herein, we evaluate the reversibility of membrane wetting induced by different types of contaminants and elucidate the underlying mechanisms. From direct contact MD experiments and membrane wettability characterizations, membrane wetting induced by amphiphilic molecules, low-surface-tension liquids, and highly soluble salts can be easily reversed by 20-min DI water rinsing and oven drying, while to reverse membrane wetting induced by sparingly soluble salts, 3-h DI water rinsing and oven drying are required. Based on microscopic imaging and elemental mapping, the membrane wetting processes did not induce severe damage to membrane structure, and thus the hydrophobicity of the membrane can be restored after the contaminants were removed from the membrane. Furthermore, the mechanisms of the removal of different contaminants are elucidated. Specifically, after membrane rinsing and drying, the amphiphilic molecules automatically desorb from the dried membrane due to the disappearance of the underwater hydrophobic-hydrophobic interaction, while the low-surface-tension liquids leave the membrane pores because of evaporation. Additionally, during the membrane rinsing process, the highly soluble salts inside the membrane pores are dissolved, while the sparingly soluble salts detach from the membrane due to the hydrodynamic disturbance. The insights from this study shed lights on the development of effective dewetting techniques for hydrophobic membranes, which benefits not only MD but also membrane contactor applications.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
ACS ES&T Engineering
·
2024
·
IF 7.4
Dejun Feng,Shaodan Xie,Wenting Zhou,Yuanmiaoliang Chen,Zhangxin Wang
Membrane wetting is a prominent challenge in the practical applications of membrane distillation (MD). In this study, we hypothesize that increasing the hydraulic pressure on the distillate side (Pd) can mitigate membrane wetting, an operation mode we refer to as pressurizing distillate membrane distillation (PDMD). To implement PDMD, an accurate measurement of the liquid entry pressure (LEP) of the membrane with the feed solution is essential. However, the conventional LEP measurement method struggles with solutions containing amphiphilic agents. Herein, we develop an impedance-based LEP measurement method and validate it by measuring the LEPs of a commercial poly(tetrafluoroethylene) (PTFE) membrane with ethanol–water mixtures. Further, we demonstrate that this method can accurately measure the LEPs of the PTFE membrane with solutions containing sodium dodecyl sulfate (i.e., a representative amphiphilic agent) by capturing the subtle changes of the feed solutions within the membrane. Additionally, we show that PDMD can effectively mitigate membrane wetting induced by various wetting agents, as the elevated Pd results in a transmembrane hydraulic pressure lower than the LEP of the membrane. Overall, our study provides an effective wetting mitigation approach that can be easily applied in practical MD and membrane contactor applications.
研究领域:
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
DESALINATION
·
2014
·
IF 3.96
Feng Wang,Jiuming Li,Hailin Zhu,Huapeng Zhang,Hongyan Tang,Jianyong Chen,Yuhai Guo
In order to remit the membrane wetting in membrane distillation (MD), polytetrafluoroethylene (PTFE) flat membrane with low surface free energy and high water contact angle (WCA) was prepared by a simple heat setting process. Membrane morphology evolution, such as breakage of fibrils and fusion of PTFE resin, and its influence on membrane characters including pore size, porosity and roughness were discussed. The effect of the heat setting process on the membrane wetting was evaluated by the membrane wetting time (MWT) in a static absorption experiment (SAE) and sweep gas membrane distillation (SGMD). The results show that the crystallinity decreases with increasing the heat setting temperature and time, which leads to low surface free energy and therefore low adsorbing capacity of penetrating agent and the long wetting time in the static absorption experiment and SGMD. In addition, pore size increases firstly and then decreases due to the breakage of fibrils and fusion of PTFE resin, respectively, which further affects the permeate flux . Therefore, we propose that the anti-fouling property and separation performance of PTFE flat membrane in SGMD can be well handled and hope that such a PTFE flat membrane would be potentially useful in seawater desalination .
研究领域:
材料科学
·
环境工程
✓ 已验证
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2022
·
IF 4.326
Lei Jiao,Lida Meng,Kangkang Yan,Jing Wang,Ge Li,Zhikan Yao,Zhilin Sun,Lin Zhang
Membrane wetting is a crucial issue in the desalination process by vacuum membrane distillation (VMD). However, the micromechanism of the wetting behavior is far from clear. Here, electrospun nanofiber membranes (ENMs) had been utilized to clarify the pore variations inside the membrane for desalination from NaCl aqueous solution, where the distinct open pore structure of ENMs could address the characterizing limitations for the change occurring in the membrane pores. A wetting formation model had been depicted on the basis of characterized results, illustrating that the basic reason for wetting was the initial NaCl crystallization caused by supersaturation, which was different from the membrane pores blocking or the structure damage caused by scaling. Moreover, membrane regeneration experiments also showed that the wetting caused by the crystallization of NaCl was reversible. By a reasonable regeneration strategy, VMD used for desalination was expected to achieve continuous operation with rejection over 99.9%.
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
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2019
·Vol. 166
·期 8
·A1456
·
IF 3.12
Hao Zheng,Xin Zhou,Sheng Cheng,Ru Xia,Shuping Nie,Xin Liang,Yi Sun,Hongfa Xiang
Influence of separator wettability toward nonaqueous electrolyte was investigated in lithium-ion batteries using high-voltage LiNi0.5Mn1.5O4 cathode. A fluorinated ether of 1,1,2,2-tetrafluoroethyl 2,2,3,3-tetrafluoropropyl ether (HFE) was introduced as a co-solvent into the control electrolyte and polyolefin separator wettability toward nonaqueous electrolyte was effectively enhanced. Even though conductivity of the electrolyte bulk decreased after HFE was introduced, ionic conductivity of the electrolyte-soaking separator increased due to the enhanced separator wettability. From cycling stability of the half cells using high-voltage LiNi0.5Mn1.5O4 cathode, all electrolytes containing 10%, 20% and 30% HFE have superiority to the control electrolyte, and the 20% HFE containing electrolyte is the optimal. Microscopical analysis revealed that oxidative decomposition of HFE-containing electrolyte on the LiNi0.5Mn1.5O4 cathode was suppressed effectively with the thinner cathode electrolyte interface than that in the control electrolyte. In Li4Ti5O12|LiNi0.5Mn1.5O4 full cells, the 20% HFE containing electrolyte exhibited the enhanced cycling stability and rate capability compared to the control of 1 mol L−1 LiPF6/propylene carbonate. This work here reveals the effect of fluorinated ether co-solvent on separator wettability and further the superior separator wettability is critical to the oxidation stability of the electrolyte in lithium-ion batteries using high-voltage cathode.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
COLLOID AND POLYMER SCIENCE
·
2021
·Vol. 300
·期 4
·297-307
·
IF 1.931
Hu Yuning,Gong Fangling,Yan Xingran,Li Tong,Chen Jingkun,Wei Wei,Ma Guanghui
The low percentage of pores at which droplets are formed results in lower production efficiency, which is one of the main issues hampering the application of microporous membrane emulsification on a large scale. The effect of microporous membrane pore activation on the droplet’s formation and emulsion performance was systemically investigated by changing both transmembrane pressures and membrane wettability during membrane emulsification. It indicated that the high transmembrane pressure increased the pore activation ratio (the percentage of pores at which droplets are formed) by the growing flux. These induced the enhancements of emulsification efficiency and the degradation of emulsion performance. Different wettability of membrane inflow and outflow influenced the pore activation speed (the speed which droplets are formed at pores). It indicated that the wettability of membrane outflow had a key effect on droplet formation and the high pore activation speed avoided splashing for high emulsion performance.
研究领域:
化学工程
·
材料科学
·
胶体与界面科学
✓ 已验证
产品关联
DOI
高影响因子
DESALINATION
·
2023
·
IF 9.9
Chuqing Cao,Fengnan Liu,Fangqing Li,Onyeagoro Robinson Uzochukwu,Lin Chen
Membrane distillation (MD) is a promising desalination technology that combines traditional distillation processes with membrane separation technology , but when the feed solution contains amphiphilic substances such as surfactant, the hydrophobic membrane is prone to being wetting, which hinders its widespread application. In this study, a novel Janus membrane was developed by embedding Zr-MOF and silver nanowires into the modified graphene oxide composite membrane to improve its separation performance, and the effect of high-concentration SDS on the membrane performance was studied. The experimental results showed that the conductive membrane exhibited excellent performance when powered on for 5 min every 2.5 h under 2 V voltage. The flux stabilized at 19.6 L/(m 2 h) with a desalination rate up to 99.9 % and no obvious signs of membrane wetting. It was found that the effect of electric field caused a negative charge on the membrane surface , forming a charge repulsion force with the SDS. Simultaneously, intermittent electrical flotation can effectively remove SDS that has accumulated on the membrane surface, thus achieving efficient and stable operation of MD system. Moreover, a machine learning approach with Catboost was applied to predict and unveil the complex effects on membrane performance, providing a deep insight to treat wastewater containing surfactant.
研究领域:
材料科学
·
环境工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
ENERGY & FUELS
·
2015
·
IF 2.79
Hongyan Tang,Yi Zhang,Feng Wang,Huapeng Zhang,Yuhai Guo
Membrane wetting is the main obstacle for carbon dioxide (CO2) capture on long-term operation. In order to understand wetting, polytetrafluoroethylene (PTFE) hollow fiber membranes were fabricated through paste extrusion, stretching, and sintering processes. CO2 capture performance over 180 days was performed. It indicates no obvious deterioration of CO2 flux over 180 days. Subsequently, further investigation was performed through immersion of PTFE hollow fiber membranes in different absorbent solutions. Results of Fourier transform infrared (FTIR) spectroscopy, energy-dispersive spectroscopy (EDS), and variations of membrane weight showed the PTFE polymer kept good stability in the absorbent solutions over 24 weeks. Scanning electron microscopy (SEM) images indicated the pore sizes of the PTFE hollow fiber membranes did not markedly enlarge during immersion, which was proved by pore size distributions. Contact angle measurements indicated no obvious reduction (8° reduction) in the membrane hydrophobicity over 24 weeks. Values of the contact angle relied on the surface tension values of the absorbent solutions. AFM images showed that immersion imposed a negative influence on the roughness values, which was the same order as the contact angle. The results suggested that none of the absorbent molecules entered the interior of the PTFE polymer. PTFE hollow fiber membranes may be a promising alternative for CO2 capture on long-term operation.
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
·
2024
·
IF 8.3
Wenting Li,Mengdi Chen,Ganwei Zhang,Weicai Chen,Lei Zhang,Shusu Shen,Dapeng Liu,Xiaoji Zhou,Yaoliang Hong
The DCMD technology for wastewater treatment is very promising. However, it is easily suffered by membrane fouling and wetting. In this study, a Janus membrane was fabricated by coating polyvinylamine (PVAM) and gallic acid (GA) onto one side of a PVDF composite membrane, which another side is covered with POTS-SiO 2 . The PVAM and GA side could bind water to form a hydration layer, thus repel the contaminants. The POTS-SiO 2 side was superhydrophobicity and prevented the membrane wetting. Finally, The Janus membrane presented exceptional performance in separating salt containing emulsified oil by DCMD. It kept a stable flux of 17.0 ± 0.2 Kg·m −2 ·h −1 and a low level conductivity of 0.60 ± 0.02 μS/cm in the cold side during the 36 h DCMD procedure, compared with the pristine PVDF membrane and the PVDF/POTS-SiO 2 membrane. The results presented simultaneously antifouling and antiwetting properties of the Janus membrane. While the Janus membrane can be well used in desalination of emulsified oil containing salt, it has a great potential for application to treat other complex wastewater.
研究领域:
环境工程
·
膜科学
·
水处理
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING RESEARCH & DESIGN
·
2023
·
IF 3.9
Nor Hafiza Ismail,Wan Norharyati Wan Salleh,Farhana Aziz,Norhaniza Yusof,Juhana Jaafar,Ahmad Fauzi Ismail,Ahmad Hafizal Mohd Yamin
Oily wastewater poses a significant environmental concern as it has adverse effects on both ecosystems and human health. The development of highly efficient and robust antifouling membranes for oily emulsion is in great demand to prevent these serious issues in oil/water emulsion filtration. Moreover, fouling was inevitable when dealing with membrane separation . In order to overcome the addressed matters, this paper reported sprayed hydrophilic surface coating using commercialized levodopa ( L -DOPA). The coated solution was mixed with 3-amino-propyltriethoxysilane in various ratios to obtain a smooth coated layer. Based on the results, the highest pure water flux and rejection efficiency of 586.51 ± 23.95 L/m 2 ‧h and 98.22% was achieved in this study, respectively. The abundant hydroxyl and carboxyl functional groups on the membrane surface from L -DOPA benefit the membrane in many ways, especially the membrane wetting properties. The water and oil contact angles of the coated membrane increased by approximately 75% and 85%, respectively. The fouling behaviors are influenced by the presence of the coated layer, resulting in the attainment of 90% fouling resistance ratio (FRR). This is mostly due to the reduction in adherence of oil droplets on the membrane surface, hence enhancing the effectiveness of the anti-oil fouling membrane . Additionally, this provides excellent properties of the membrane to be applied in oily wastewater treatment .
研究领域:
环境科学
·
材料科学
·
化学工程
✓ 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）