SEPARATION AND PURIFICATION TECHNOLOGY
·
2017
·
IF 3.359
Sheng Xu,Lifen Liu,Yan Wang
Amine cross-linking is one of the popular modifications of polyimide membranes in order to improve their operation stability and separation performance. In this work, a novel kind of cross-linker tricarbohydrazide — 1,3,5-benzenetricarboxylic acid trihydrazide (BTCH), is synthesized and incorporated into polyimide membranes for isopropanol dehydration via pervaporation. The chemical structure of BTCH is examined by NMR and FTIR to confirm the successful synthesis. The effects of BTCH content and membrane-forming temperature on the membrane physicochemical properties and separation performance are studied and characterized by various techniques. And the possible reaction mechanism during the chemical cross-linking is proposed and analyzed. This work is believed to shed useful insights on the chemical modification of polyimide membranes for pervaporation and other membrane-based separation applications.
研究领域:
材料科学
·
分离技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2015
·
IF 5.056
Ling Ling Xia,Cai Lian Li,Yan Wang
In this work, two novel poly(vinyl alcohol) (PVA)/organosilica hybrid membranes are developed via the sol–gel process, with phenyltriethoxysilane (PTES) and diethoxydiphenylsilane (DEDPS) as crosslinkers and organosilica precursors, and employed for ethanol dehydration via pervaporation . Effects of organosilane type on the membrane morphology, physicochemical properties and pervaporation performance of the as-fabricated membranes are studied. In addition, the effects of the organosilane loading and the thermal treatment temperature on the physicochemical properties and pervaporation performance of the membrane are explored systematically. Various characterization techniques (FT-IR, TGA, SEM , etc) are employed to illuminate physicochemical changes of membranes. The optimal pervaporation performance of PVA–PTES hybrid membrane with 0.4 mmol/g PTES loading and thermally treated at 80 °C has a flux of 145 g/m 2 h and a separation factor of 1026 for the pervaporation dehydration of 85% ethanol aqueous solution at 40 °C.
研究领域:
化学工程
·
膜科学
·
材料科学
·
分离技术
✓ 已验证
DOI
高影响因子
Materials Today Communications
·
2024
·
IF 3.7
Weibin Cai,Qi Zhang,Gary Q. Yang,Hong Ye,Meijie Song,Zhiping Wang
Pervaporation membranes are used to dehydrate ethanol, but standalone sodium alginate (SA) and polyvinyl alcohol (PVA) membranes pose challenges owing to their inherent issues, such as low stability and limited separation performance. Despite employing various complex and costly membrane preparation methods to address these shortcomings, the improvement in separation performance, especially in permeate flux , remains limited. In addition, the complexity and costliness of these methods hinder their industrial applications. Herein, we developed a simple and cost-effective method to prepare high-performance pervaporation membranes. First, a SA solution was cast on the polyacrylonitrile (PAN) bottom membrane to form a SA separation layer, and subsequently a PVA separation layer was applied atop of the SA separation layer, yielding double-separation-layer PVA/SA/PAN membranes. The smooth, compact and hydrophilic SA intermediate layer apparently decreased the defects in the PVA separation layer and the presence of the PVA separation layer isolated the SA layer from the liquid feed on the outer side and inhibited the swelling of SA separation layer, leading to high selectivities and stabilities. Under operating conditions of 69°C and a feed ethanol concentration of 90 wt%, the permeate flux and separation factor of the PVA4/SA/PAN membrane are 1201 g m −2 h −1 and 5164, respectively. Notably, the pervaporation separation index (PSI) of this membrane is 79 times that of the PVA4/PAN membrane. Moreover, the membrane performance remained stable over a continuous 10-day operation at 69°C, affirming its reliability and durability. We successfully prepared a high-performance two-separation-layer pervaporation membrane for ethanol dehydration.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2022
·
IF 10.53
Wenhe Yang,Xue Yang,Yuxuan Wang,Rujing Hou,Qihan Gong,Yichang Pan
The metal-organic framework (MOF) membrane has been widely studied in gas separation applications. However, less attention was paid to organic liquids separation, particularly for the separation of straight and branched alkane isomers which is critical to producing high-octane gasoline. Our work is the first example of a dense and defect-free Al-bttotb membrane synthesized on α-Al 2 O 3 support surface through solvothermal in-situ synthesis. The microstructure of the membrane surface was adjusted by controlling the growth rate of the crystal facet through the addition of formic acid during synthesis. The resultant membrane showed great thermal stability, long-term stability, and chemical stability due to the bonding reaction between the ligands and the support surface. The pervaporation test showed that Al-bttotb membrane preferentially permeated straight and mono-branched alkane. The mass fraction of n-hexane (nHEX, straight) and 3-methylpentane (3MP, mono-branched) was accumulated from 66.66% on the feed side to 88.53% on the permeate side after 20 h of the test, while a mass fraction of 2,2-dimethylbutane (22DMB) decreased from 33.33% to 11.47%. This work sheds new light on the separation of organic liquids through MOF polycrystalline membrane.
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2015
·
IF 5.056
Sheng Xu,Yan Wang
In this work, two novel carboxyl-containing polyimides , 2,2′-bis(3,4-dicarboxyphenyl) hexafluoropropane dianhydride-4,4′-diaminodiphenylmethane/3,5-diaminobenzoic acid (6FDA-MDA/DABA, FMD) and 3,3′,4,4′-benzophenone tetracarboxylic dianhydride-4,4′-diaminodiphenylmethane/3,5-diaminobenzoic acid (BTDA-MDA/DABA, BMD), are synthesized via chemical and thermal imidization methods, respectively, and employed as pervaporation membranes for ethanol dehydration. Chemical structures of the two polyimides are examined by FTIR and TGA to confirm the successful synthesis. A post thermal treatment of the polyimide membranes with the temperature range of 250 to 400 °C is applied, and its effects on the membrane morphology and separation performance are studied and characterized by FTIR, TGA, WXRD, solubility and sorption test. It is believed that the thermal treatment of the carboxyl-containing polyimide membrane at a relative low temperature only leads to the physical annealing, while it may cause the decarboxylation-induced cross-linking at a higher temperature. In addition, the operation temperature in pervaporation is also varied and shown to be an important factor to affect the final membrane performance. Performance benchmarking shows that the developed polyimide membranes both have superior pervaporation performance to most other flat-sheet dense membranes. This work is believed to shed useful insights on polyimide membranes for pervaporation applications.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
POLYMER ENGINEERING AND SCIENCE
·
2017
·Vol. 57
·期 10
·1127-1135
·
IF 1.449
Liangliang Liu,Xiaolong Han,Wenling Hu,Binxia Zhao,An Fan
Polydimethylsiloxane (PDMS), as one of the typical membrane, has been widely applied in gasoline desulfurization via pervaporation. In this work, the PDMS/PVDF composite membranes were prepared by curing PDMS with three different crosslinking agents. They were 3-Aminopropyltrimethoxylsilane (APTMS), 3-Glycidyloxypropyltrimethoxylsilane (GPTMS), and 3-Mercaptopropyltrimethoxylsilane (MPTMS), respectively. These PDMS/PVDF composite membranes were characterized by Fourier transform infrared (FT-IR), X-ray photoelectron spectroscopy (XPS), Scanning electron microscopy (SEM), and then evaluated by static tensile test, swelling degree test and surface detach experiment. The results showed that A-PDMS membrane had highest crosslinking density, best anti-swelling ability and excellent combination between the separation layer and support layer. Moreover, the effect of operation temperature and the feed sulfur content on separation performance were investigated systematically. Experimental results indicated that PDMS membrane crosslinked with APTMS presented the highest enrichment factor with 3.46°C at 45°C, and PDMS membrane crosslinked with MPTMS presented the highest permeation flux with 21.19 kg/(m 2 ·h) at 45°C. Finally, long-term stability test showed that these PDMS membranes all have desirable stability. POLYM. ENG. SCI., 57:1127–1135, 2017. © 2017 Society of Plastics Engineers
研究领域:
高分子科学
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膜技术
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化学工程
·
分离过程
·
材料科学
✓ 已验证
DOI
高影响因子
Advanced Membranes
·
2023
·
IF 0
Zhihu Zhao,Guoke Zhao,Gongqing Tang,Yiqun Liu,Pei Li
In this study, a multi-layer pervaporation composite membrane was prepared by spray-coating a hydrophilic layer consisting of poly(allylamine hydrochloride) (PAH)/polyvinyl alcohol (PVA)/trimesic acid (BTA) onto a polyethersulfone (PES) porous substrate. The presence of amine groups facilitated the transport of water molecules, enabling the composite membrane to exhibit excellent water/ethanol separation properties. When a feed solution consisting of 90 wt% ethanol and 10 wt% water was dehydrated using the PV membrane at 70 °C, a flux of 1.46 kg m −2 h −1 with a water/ethanol separation factor of 3300 was realized. In addition, after coating a 267 nm silicone rubber layer on top of the membrane, the separation factor was further increased by 70.79 % to 5285, while the flux was slightly decreased by 12.33 % to 1.28 kg m −2 h −1 . This was because the hydrophobic silicone rubber layer reduced the water swelling effect of the selective layer and hindered the permeation of ethanol-water coupling molecules, resulting in a reduction in the ethanol flux of the composite membrane and an improvement in the separation factor. This simple but effective method to improve dehydration properties was very useful for fabricating PV composite membranes.
研究领域:
材料科学
·
化学工程
·
膜技术
✓ 已验证
DOI
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Zhongxiao Du,Shun Gong,Zijian Yu,Kai Pan,Rui Zhang
In this study, we synthesized and developed a novel desalination pervaporation (PV) composite membrane material. The matrix consisted of customized thermoplastic polyether block-amides (PEBA), and a hydrophilic interpenetrating chemical cross-linking structure was formed by the addition of polyethyleneimine (PEI) and ethylene glycol diglycidyl ether (EGDE) to make PEBA/PEI/EGDE/PTFE composite membranes. In order to improve the desalination performance, we investigated the effect of changing the ratio of PEI, EGDE and PEBA in the separation layer on the desalination efficiency of the composite PV membrane. Under the optimal conditions, the PEBA/PEI/EGDE/PTFE (M 4-1 ) composite membrane exhibited a water flux of 74.04 ± 0.79 kg/(m 2 ·h), and the salt rejection was maintained at 99.9 % in a 3.5 wt% NaCl solution at 70 °C. The M4-1 composite membrane also exhibited excellent acid-base stability, demonstrating salt removal rates after treatment in solutions at both pH = 2 and pH = 14, with removal exceeding 99.9 % in both cases after 360 h. Additionally, the measured water flux of the M 4-1 composite membrane was 39.84 ± 0.17 kg/(m 2 ·h) at 70 °C and a NaCl concentration of 20 wt%, highlighting its potential for treating high salinity solutions. This study presents a strategy of physical and chemical cross-linking of interpenetrating hydrophilic modified structures, which sheds light on the long-term stable operation of PV desalination membranes and lays the foundation for industrial applications in the concentration and purification of seawater or high salinity water under complex conditions.
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
CHEMICAL ENGINEERING & TECHNOLOGY
·
2018
·Vol. 42
·期 1
·65-72
·
IF 1.588
Yingfei Hou,Yang Xu,Haiping Li,Yiyu Li,Qingshan Jason Niu
Pervaporation (PV) has many potential advantages in fluid catalytic cracking (FCC) gasoline desulfurization. The PV membrane performance was improved by incorporating SiO 2 nanoparticles in polyvinyl butyral (PVB). The coupling agent was used to enhance the compatibility between the inorganic phase and the organic phase to avoid the occurrence of film defects. Polyurethane membranes were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and atomic force microscopy. To evaluate the PV performance, the real FCC gasoline was tested. The effects of the SiO 2 content, the operating temperature, and the active layer thickness on the PV performance of the PVB/SiO 2 membranes were investigated.
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Royal Society Open Science
·
2019
·Vol. 6
·期 7
·
IF 2.515
Yifang Li,Dandan Yan,Yanhui Wu
Because of the preferential butanol selectivity of some ionic liquids (ILs), an increasing amount of research has appeared regarding their application in butanol separation. In this research, two ionic liquids, namely, 1-ethyl-3-vinylimidazolium bis[(trifluoromethyl)sulfonyl]imide ([EVIM][Tf2N], IL1) and N-octyl-pyridinium bis[(trifluoromethyl)sulfonyl]imide ([OMPY][Tf2N], IL2), were applied to modify a mesoporous molecular sieve MCM-41. The IL-modified MCM-41 samples were characterized by XPS, BET, XRD, SEM and TEM. The ionic liquid-modified MCM-41 was incorporated into the polymer PEBA to prepare mixed matrix membranes to study the influences of the filling of IL-modified MCM-41 and operating conditions on the performance of the mixed matrix membrane for butanol pervaporation. The results indicated that the pervaporation performance of the PEBA membrane was enhanced by the incorporation of IL-modified MCM-41. When the temperature of the feeding liquid was 35°C and the mass fraction of butanol was 2.5 wt%, the 5% MCM-41-IL2-PEBA membrane showed a permeation flux of 421.7 g m−2 h−1 and a separation factor of 25.4. The permeation flux and the separation factor of the membrane increased as the temperature of the feeding liquid increased. The results of the long-period experiment suggested that the 5% MCM-41-IL2-PEBA membrane exhibited high stability within 100 h of operation.
研究领域:
化学工程
·
材料科学
✓ 已验证
DOI
高影响因子
DESALINATION
·
2025
·
IF 9.8
Wuqi Cai,Dongpu Hu,Huying Li,He Wen,Yimeng Shi,Jing Wang,Ziwen Dai,Wenbo Yu,Sha Liang,Jiakuan Yang,Shushan Yuan
Membrane-based methods offer a promising alternative for phosphoric acid concentration, addressing the limitations of conventional techniques. In this study, we employ a pervaporation system to achieve phosphoric acid concentration, evaluating its efficiency and stability under industrial-relevant conditions. Composite PVA-COF membranes were successfully prepared through vacuum filtration of TpPa-SO 3 H nanosheets and PVA on hydrophilic polytetrafluoroethylene (PTFE) support membranes and the followed crosslinking with glutaraldehyde. The incorporation of PVA effectively eliminates boundary defects and enhances the mechanical and operational stability of the composite membrane. The optimum COF-PVA composite membrane exhibits excellent rejection of NaCl (99.9 %) and an ultrafast water flux of 268.6 kg m −2 h −1 . The water flux surpasses that of most reported membranes. Moreover, the membrane exhibited outstanding acid resistance and durability in phosphoric acid concentration tests, maintaining stable operation for 420 min at 40 °C with no phosphorus leakage detected in permeate. The membrane demonstrated notable concentration efficiency, achieving an increase in phosphoric acid concentration from 20 % to 25 % during a sustained 180-min operational period at 70 °C. This work helps to explore the prospects for the application of pervaporation membranes in the fields of seawater desalination and phosphorus chemical industry. Synopsis The hybrid membrane composed of poly (vinyl alcohol) and covalent organic framework, which is characterized by high permeate flux, salt rejection rate and acid stability.
研究领域:
材料科学
·
化学工程
·
膜技术
·
分离过程
·
可持续化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2024
·
IF 8.4
Qian Wang,Changchao Zhou,Li Shen,Eryue Song,Yu Yang,Haiqian Lian,Rujing Hou,Yichang Pan
The pervaporation (PV) technology is attractive for azeotrope component separation of the MeOH/MTBE mixture due to the reduced energy and cost relative to the traditional ternary distillation process. However, the membrane separation performance is largely affected by its microstructure including pore size and shape as well as its surface properties such as hydrophilicity. Herein, we report a Co-gallate MOF membrane that features preferential adsorption and diffusion of methanol (MeOH) relative to the methyl tert -butyl ether (MTBE) molecules during the PV separation process. The high-quality Co-gallate MOF membrane has been prepared by introducing a regulator of KOH. The MeOH flux of the Co-gallate MOF membrane was 0.565 kg m −2 h −1 and the separation factor was up to 721 at 15 wt% MeOH/MTBE feed composition. It is worth noting that the separation performance exceeds most of the reported membrane materials for MeOH/MTBE separation in the PV process. Furthermore, the separation performance of the Co-gallate MOF membrane for MeOH/MTBE mixtures remained almost unchanged over 70 h, indicating the reliable long-term stability of the membrane. Thus, the Co-gallate MOF membrane demonstrated a potential practical application for MeOH/MTBE separation.
研究领域:
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）