SEPARATION AND PURIFICATION TECHNOLOGY
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2023
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IF 8.6
Wanzheng Ren,Jian Pan,Wenqiang Gai,Xinyu Pan,Haimei Chen,Jiao Li,Lilan Huang
A crucial step in the purification and recycling of industrial waste oil is the separation and removal of trace water from emulsified oil. After optimizing the polymer content, solvent composition, and SiO 2 nanoparticle addition amount of the spinning precursor solution, a Polyvinylidene fluoride- co -trifluoroethylene chloride (PVDF-CTFE)/SiO 2 nanofibrous membrane with micro and nano-rough structure was prepared by electrospinning. Using scanning electron microscopy, a pore size analyzer, a contact angle tester, a single-fiber strength tester, and a gravity separation experiment, the influence of SiO 2 addition on the morphology, pore size distribution , wettability , mechanical, and separation properties of the modified membranes was characterized. The results demonstrated that the water contact angle of the nanofibrous membrane was increased to 151.3° of superhydrophobic when SiO 2 was added at a concentration of 2.5 wt%. The nanofibrous membranes exhibited outstanding separation performance (>99%) for water-in-oil mixtures and emulsions, as well as for various oil-water systems. Moreover, the PVDF-CTFE/SiO 2 nanofibrous membranes exhibited superior multi-cycle performance and consistent chemical resistance. This research yielded a novel material and a straightforward method for fabricating superhydrophobic nanofibrous membranes, which demonstrated greater application potential in oil-water separation.
研究领域:
材料科学
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环境工程
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DOI
高影响因子
RSC Advances
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2024
·Vol. 14
·期 17
·11992-12008
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IF 3.9
Xinyu Pan,Jian Pan,Zhuoqun Li,Wenqiang Gai,Guangshun Dong,Min Huang,Lilan Huang
Poly(vinylidene fluoride-co-chlorotrifluoroethylene) (PVDF-CTFE) is considered an ideal membrane material for the treatment of complex environmental water due to its exceptional thermal stability and chemical resistance. Thus, to expand its application in the field of nanofiltration (NF) membranes, in this study, N-methylglucamine (N-MG) was used to hydrophilically modify PVDF-CTFE, overcoming the inherent hydrophobicity of PVDF-CTFE as a porous substrate membrane, which leads to difficulties in controlling the interfacial polymerization (IP) reaction and instability of the separation layer structure. The –OH present in N-MG could replace the C–Cl bond in the CTFE chain segment, thus enabling the hydrophilic graft modification of PVDF-CTFE. The influence of the addition of N-MG on the surface and pore structure, wettability, permeability, ultrafiltration separation, and mechanical properties of the PVDF-CTFE substrate membrane was studied. According to the comparison of the comprehensive capabilities of the prepared porous membranes, the M4 membrane with the addition of 1.5 wt% N-MG exhibited the best hydrophilicity and permeability, indicating that it is a desirable modified membrane for use as an NF substrate membrane. The experiments showed that the rejection of Na2SO4 by the NF membrane was 96.5% and greater than 94.0% for various dyes. In the test using dye/salt mixed solution, this membrane exhibited a good separation selectivity (CR/NaCl = 177.8) and long-term operational stability.
研究领域:
环境科学
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材料科学
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产品关联
DOI
PubMed
高影响因子
Journal of Water Process Engineering
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2021
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IF 5.485
Wenyi Ma,Wanzheng Ren,Xiaoyu Bai,Jian Pan,Lilan Huang,Qinglin Huang,Zengge Guo,Xinyan Wang
Poly (vinylidene fluoride) (PVDF) has been widely implemented in fabricating membranes, but pure PVDF membrane need to be modified by blending or copolymerization to cope with its weak alkali resistance. In this work, the function of chlorotrifluoroethylene (CTFE) chain segment was studied, PVDF/ECTFE blending membranes and poly (vinylidene difluoride- co -chlorotrifluoroethylene) (PVDF-CTFE) membranes were prepared via non-solvent induced phase separation (NIPS) method. The effect of modification methods and solvents on the membrane morphology, micropore and physicochemical structure, permeability, ultrafiltration performance, anti-fouling property and alkali resistance were investigated systematically. More than that, the surface charge and roughness of membrane prepared by different solvents were determined in the varying environment to better understand the anti-fouling property. The result presented that the comprehensive properties of PVDF-CTFE copolymerization membrane were better than that of PVDF/ECTFE blending membrane. The microporous structure of PVDF-CTFE membrane surface and sublayer was optimized by adjusting the solvent. The effect of solvent on the rate of L-L de-mixing during phase inversion was investigated from thermodynamic and kinetic factors. The prepared PVDF-CTFE membrane using N -methylpyrrolidone (NMP) as solvent broke the trade-off between the permeability and selectivity, so it was simultaneously possessed superior pure water flux (306.5 L·m −2 ·h −1 ) and higher BSA rejection rate (98.4%). The combination of NMP and PVP significantly decreased the rate of phase inversion without changing the polymer content, and provided a simple and feasible improvement idea for non-solvent-induced phase separation. In addition, the PVDF-CTFE membranes possessed better alkali resistance compared to PVDF membranes, demonstrating its promising potential in harsh environment.
研究领域:
材料科学
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环境工程
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DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
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2024
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IF 8.4
Wanzheng Ren,Jian Pan,Zhuoqun Li,Min Huang,Lilan Huang,Liqiang Gu,Hailin Cong
The substrate membrane plays a crucial role in determining the performance of composite nanofiltration membranes prepared by interfacial polymerization (IP). In this study, persistent hydrophilic modification of polyvinylidene fluoride-co-chlorotrifluoroethylene (PVDF-CTFE) was achieved by incorporating N-methylglucamine (N-MG) without altering the membrane's morphology or pore size. Moreover, thin-film nanofibrous composite (TFNC) nanofiltration membranes were prepared using the surfactant assembly regulated interfacial polymerization (SARIP) method with the modified PVDF-CTFE@N-MG nanofibrous membrane as the substrate. The effect of N-MG addition on the substrate membrane's hydrophilicity and the structure and performance of the polyamide (PA) separation layer was investigated. The results showed that the addition of N-MG significantly improved the hydrophilicity of the PVDF-CTFE nanofibrous membrane. The TFNC-5 membrane, prepared with the modified PVDF-CTFE@N-MG nanofibrous membrane as the substrate, exhibited permeability exceeding 13.5 L m −2 h −1 ·bar −1 for various dye solutions at 3 bar pressure, with rejection rates above 98 %. It also demonstrated excellent selective separation performance (separation factor for NaCl/Orange G reaching 97.38) and long-term operational stability. This work provides a method for the preparation of low-pressure, high-flux nanofiltration membranes, which is applicable to seawater desalination and dye 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
高影响因子
JOURNAL OF MEMBRANE SCIENCE
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2022
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IF 10.53
Wenyi Ma,Jian Pan,Wanzheng Ren,Long Chen,Lilan Huang,Shanshan Xu,Zhaohui Jiang
Despite membrane separation technology has been extensively implemented in various field, the fouling caused by bacterial and organic dye seriously impair the performance and lifespan of the membrane, the anti-fouling modification of the membrane is still a challenging. In this work, the antibacterial and self-cleaning poly (vinylidene fluoride-chlorotrifluoroethylene) (PVDF-CTFE) mixed matrix membranes were prepared by non-solvent induced phase separation method using self-made graphite carbon nitride nanosheet wrapped copper phosphide (Cu x [email protected] 3 N 4 ) as modification additive. The sequel of the incorporated Cu x [email protected] 3 N 4 nanosheet content on the morphology, pore structure and physicochemical structure of membranes was investigated in terms of pure water flux, anti-fouling and antibacterial properties. The results showed that the addition of Cu x [email protected] 3 N 4 nanosheets not only improved the hydrophilicity and mechanical property of the membranes, but also enabled PVDF-CTFE membrane with the ability of inactivation bacteria and self-cleaning, which significantly enhanced the anti-fouling performance of PVDF-CTFE membrane in complex environment. When the amount of Cu x [email protected] 3 N 4 reached 2 wt%, the mixed matrix membrane possessed outstanding comprehensive performance with the pure water flux of 641.1 L m −2 h −1 , antibacterial rate over 99% and self-cleaning under simulated sunlight, making the mixed matrix membrane a potential choice for wastewater treatment . In conclusion, this study enlightened the fabrication strategy of multifunctional mixed matrix membranes.
研究领域:
膜科学
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材料科学
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环境工程
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纳米技术
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DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
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2022
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IF 10.53
Ronghua Ma,Xiaolong Lu,Shaozhe Zhang,Kai Ren,Jie Gu,Chao Liu,Ziqiang Liu,Hanli Wang
In recent years, membrane separation technology has been widely used in various fields. And for the increasingly severe oily wastewater system, there is an increasing demand for the anti-fouling properties of the membranes. Based on the concept of fluorine-free, non-toxic, environmental-friendly and low-cost, this study constructed a discontinuous silicon-island structure with low surface energy on the surface of the hydrophilic membrane, which endows the PVDF-CTFE membrane with fouling resistance and cleaning pH-responsiveness. The discontinuous silicon-island structures were constructed by introducing SiO 2 nanoparticles on the super-hydrophilic layer of the PVDF-CTFE membrane modified by itaconic acid, and then hydrophobically treated with polydimethylsiloxane (PDMS). The experimental results exhibited that the modified membrane reached the hydrophobic and underwater super-oleophobic state when treated by PDMS for 1.0 h. The water contact angle (WCA) and the underwater oil contact angle (OCA) were 124° and 151°, respectively. Furthermore, the water flux remained at 186 L m −2 h −1 with no serious pore-plugging. Moreover, the water flux decay rate (FDR) remained below 19.6%, when modified membrane treating soybean oil/water emulsion for 6 cycles, presenting an excellent anti-fouling performance. Additionally, the water flux recovery rate (FRR) was over 99.3% after alkali cleaning, indicating the modified membrane possessed excellent cleaning pH-responsiveness. The above analysis exhibited that the synergistic effect of hydrophilic micro-domains and oleophobic micro-domains not only slows down the attachment of hydrophobic pollutants but also promotes the separation of hydrophobic pollutants during chemical cleaning, which greatly improves its anti-fouling performance and expands its application prospect.
研究领域:
材料科学
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环境工程
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产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
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2024
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IF 8.4
Shaojin Jia,Sha Yang,Yu Pan,Salah Ud Din,Yuanjie Cai
As an important part of the fields such as renewable energy and electric vehicles, electrochemical energy storage technology faces significant challenges in improving energy density , extending battery life and improving safety. We successfully prepared a composite battery separator of polyvinylidene fluoride-chlorotrifluorinylene (PVDF-CTFE) and fluorinated polyimide (F-PI) -based materials, mixed it with different contents of boehmite nanoparticles , and then modified it by different doses of electron beam irradiation to improve the performance, especially to overcome the problem of maintaining capacity decline in high-speed charging environment. The results showed that the prepared battery separators exhibited outstanding thermal stability, electrochemical properties and ionic conductivity with 12 % boehmite nanoparticles . After 1000 high-speed charge and discharge cycles in current density of 10C, the battery based on the modified separator still maintained a capacity retention rate of 84.4 %, with the initial discharge specific capacity of 111.9 mAhg −1 . This means that irradiated separators not only maintain a high energy density in a high-speed charging environment, but also overcome the problem of maintaining capacity decline. Electron beam irradiation further improved the comprehensive performance of the separator. After 1000 and 1500 cycles at the current density of 10C and 15C, the specific discharge capacity of the battery can still retain more than 90 % and 80 % of the initial specific discharge capacity, which provides a longer life in practical applications.
研究领域:
材料科学
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电化学储能技术
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DOI
高影响因子
危险品化学品经营许可证（带存储）