CARBOHYDRATE POLYMERS
·
2020
·
IF 7.182
Yingying Cao,Yongqiang Zhang,Ying Zhang,Ling Wang,Lunchao Lv,Xifei Ma,Shaojuan Zeng,Hui Wang
Artemisinin is mainly derived from Artemisia annua L. Since the leaves composition is complex, artemisinin purification faces great challenges. In this work, functional chitosan membranes were fabricated by a one-step hydrolysis method through grafting long-chain alkyl group on the surface of chitosan to increase its hydrophobicity. The as-prepared membranes were used to adsorb wax oil ( i.e. , the impurity components) in Artemisia annua L. and to avoid co-precipitation of wax oil along with artemisinin using the crystallization technique for purification. Octyl-trimethoxysilane modified chitosan membrane (FCM-C 8 ) showed excellent capability to intensify this purification process. The product purity could reach more than 98 % using one crystallization step under the optimal conditions, and in this case, adsorption capacity of FCM-C 8 for wax oil was 478.9 mg/g. In addition, the adsorption kinetics and mechanism of wax oil on FCM-C 8 were studied. The membrane can simultaneously adsorb multiple components in wax oil through interactions like electrostatic forces, hydrogen bondings.
研究领域:
生物工程
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制药工程
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产品关联
DOI
PubMed
高影响因子
Separations
·
2022
·Vol. 9
·期 3
·64
·
IF 3.344
Weibin Cai,Jiangyu Xie,Jingyu Luo,Xiaohan Chen,Mingqian Wang,Yujun Wang,Jiding Li
In this study, zeolite molecular sieve SAPO-34/polydimethylsiloxane (PDMS) mixed matrix membranes (MMMs) were prepared to recover propane. n-Octyltrichlorosilane (OTCS) was introduced to improve compatibility between SAPO-34 and PDMS, and enhance the separation performance of the MMMs. Physicochemical properties of the MMMs were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and water contact angle (WCA). Results showed that, after modification, alkyl chains were successfully grafted onto SAPO-34 without changing its crystal structure, particles in the MMMs were evenly distributed in the base film, and the hydrophobicity of the MMMs was enhanced. Moreover, the effects of SAPO-34 filling content, operating pressure, and feed gas concentration on the separation performance was explored. This indicated that the modification with OTCS effectively enhanced the separation performance of SAPO-34/PDMS MMMs. When the filling content of modified SAPO-34 was 15%, the maximal separation factor of 22.1 was achieved, and the corresponding propane permeation rate was 101 GPU.Keywords:MMMs;SAPO-34;PDMS;OTCS;propane recovery
研究领域:
材料科学
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化学工程
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产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2020
·
IF 5.774
Rehan Khan,Ihtisham Ul Haq,Heng Mao,Ao-Shuai Zhang,Li-Hao Xu,Hong-Gang Zhen,Zhi-Ping Zhao
Phenol is highly toxic and carcinogenic even at low concentrations. This study focused on preparing high-performance mixed matrix membranes (MMMs) for the pervaporation separation of phenol from its aqueous solution. A highly-efficient zeolitic metal azolate framework, RHO-[Zn(Heim) 2 ] (MAF-6, Heim = 2-ethylimidazole) was incorporated into the polyether block amide (PEBA-2533) supported on the polyvinylidene fluoride (PVDF) ultrafiltration membrane. The MAF-6 was chosen as the filler due to its inherent hydrophobic surfaces and aperture size (7.6 Å), which is larger than the molecular kinetic diameter of phenol (6.6 Å). Effects of the casting solution concentration, active layer thickness, MAF-6 loading, operating temperature, and phenol concentration were systematically investigated. With the increase of the MAF-6 loading ratio X from 0 to 7, the phenol flux of the membrane was gradually enhanced, but the water flux was reduced. For 1000 ppm phenol aqueous solution at 80 °C, MAF-6–7@MMM displayed the optimal separation factor of 25.9 with a phenol flux of 89.2 g∙m −2 ∙h −1 . The pervaporation separation index (PSI) of the MAF-6–7@MMM was 1317.7 kg∙µm∙m −2 ∙h −1 at 80 °C, which was much higher than the PEBA/PVDF membrane (787 kg∙µm∙m −2 ∙h −1 ). Impressively, an increasing feed temperature enhanced the phenol flux more prominently than water, owing to the hydrophobicity and porosity of MAF-6. Consequently, the resultant MAF-6-X@MMMs broke the trade-off limitation between phenol permeability and selectivity. The as-prepared membrane also exhibited exceptional long-term stability, suggesting its prospect of industrial application.
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
高影响因子
CHEMISTRY-A EUROPEAN JOURNAL
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2020
·Vol. 26
·期 35
·7918-7922
·
IF 4.857
Yichen Zhou,Mingmin Jia,Xiongfei Zhang,Jianfeng Yao
Graphical Filling the voids : Etched ZIF-8 (ZIF-8-E) crystals permeated by open through pores of size about 100 nm have been introduced into a polyethersulfone membrane matrix. The resulting material shows enhanced CO 2 /N 2 separation performance (see scheme). Zeolite ZIF-8 has been etched with acid to form microporous ZIF-8-E crystals. These were then introduced into a polyethersulfone (PES) membrane matrix to enhance its CO 2 /N 2 separation performance. Open through pores of size about 100 nm formed in the ZIF-8 crystals allow the ingrowth of polyethersulfone chains, ensuring a reduction in the number of nonselective voids, thereby achieving better interaction between ZIF-8-E and PES. As a result, the CO 2 /N 2 separation performance of the ZIF-8-E/PES membrane increased significantly, showing a CO 2 permeability of 15.7 Barrer and a CO 2 /N 2 ideal selectivity of 6.5.
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
Soft Matter
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2025
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IF 2.8
Manas Kumar Mandal,Shujiao Chen,Shuai Zhang,Qunhui Yuan,Wei Gan
Biocompatible and bioavailable ionic liquids (ILs) are generally used to modify the physicochemical properties of lipid monolayers and bilayers. Understanding the influence of ILs on lipid properties and the molecular level mechanism is crucial for applying ILs in lipid membrane modifications. Here the modification of a lipid membrane composed of 1,2-dioleoyl-sn-glycero-3-phosphoglycerol (DOPG) and cholesterol using alkyl methyl imidazolium-based ILs [Cnmim]Cl with varied alkyl chains (n = 4, 6, 8 and 10) was investigated. Langmuir monolayers were used to evaluate the influence of the ILs on the rigidity and robustness of the membranes. Then, selected compositions were used to prepare small unilamellar vesicles (SUVs) as nanocarriers. A small amphiphilic molecule (4-(4-diethylaminostyry)-1-methyl-pyridinium iodide, D289) was used as a probe to investigate the loading capability and encapsulation efficiency of the SUVs. The permeability of the lipid membrane to small molecules was also evaluated using second harmonic generation spectroscopy analysis. The different effects of the ILs with increasing chain length imposed on the membranes were compared and analyzed.
研究领域:
生物物理学
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药剂学
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产品关联
DOI
PubMed
高影响因子
MOLECULES
·
2024
·Vol. 29
·期 18
·4465
·
IF 4.2
Yun Xiong,Yifan Shu,Niyan Deng,Xiaogang Luo,Shengpeng Liu,Xiaoyu Wu
This study investigated the enhancement in bioethanol recovery from mixed matrix membranes (MMMs) by functionalizing zeolite framework-8 (ZIF-8) with imidazolate. This study focused on the separation of ethanol from low-concentration ethanol/water mixtures (typical post-fermentation concentrations of 5–10 wt%). Specifically, ZIF-8 was modified by the shell–ligand exchange reaction (SLER) with 5,6-dimethylbenzimidazole (DMBIM), resulting in ZIF-8-DMBIM particles with improved hydrophobicity, organophilicity, larger size, and adjustable pore size. These particles were incorporated into a PEBAX 2533 matrix to produce ZIF-8-DMBIM/PEBAX MMMs using a dilution blending method. The resulting membranes showed significant performance enhancement: 8 wt% ZIF-8-DMBIM loading achieved a total flux of 308 g/m2·h and a separation factor of 16.03, which was a 36.8% increase in flux and 176.4% increase in separation factor compared with the original PEBAX membrane. In addition, performance remained stable during a 130 h cycling test. These improvements are attributed to the enhanced compatibility and dispersion of ZIF-8-DMBIM in the PEBAX matrix. In conclusion, the evaluation of nanofiller content, feed concentration, operating temperature, and membrane stability confirmed that ZIF-8-DMBIM/PEBAX MMM is ideal for ethanol recovery in primary bioethanol concentration processes.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION SCIENCE AND TECHNOLOGY
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2024
·
IF 2.3
Chengpeng Zhang,Hongjing Liu,Hanyu Qiu,Wei Zhao,Xu Zhao,Xiaochun Jing,Hui Yao
Nano-organic hybrid materials (Al2O3-NOHMs) were synthesized with nano-alumina as the core, γ-(2,3-epoxypropyl) propyl trimethoxysiane (KH560) as the corona, and three of polyetheramine M2070, D2000, M1000 as the canopy, respectively. Al2O3-NOHMs were used as fillers to prepare MMMs with Pebax as substrate to improve the CO2 separation performance. The Al2O3-NOHMs were characterized by TEM and rheological properties. The results showed that the synthesized Al2O3-NOHMs were liquid-like and had a core-shell structure, which can effectively reduce Al2O3 agglomeration in the membrane. FT-IR analysis of MMMs showed that Al2O3-NOHMs and Pebax were physically blended, TGA indicated that Al2O3-NOHMs do not affect the thermal stability of the membrane, and XRD indicated that the addition of Al2O3-NOHMs destroyed the interchain hydrogen bond of Pebax and reduced the crystallinity of MMMs. The gas permeability of the membrane was tested under ideal gas conditions, compared with pure membrane, the CO2 permeability of Al2O3-NOHM(M2070)/Pebax MMMs and Al2O3-NOHM(D2000)/Pebax MMMs reached 137.15 Barrer (24.68%) and 147.52 Barrer (34.11%), and the selectivity of CO2/N2 reached 77.82 (58.84%) and 72.31 (47.59%) at 30°C and 0.3 MPa, respectively, surpassing 2008 Robeson upper bound.
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 MANAGEMENT
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2024
·
IF 8
Tian Zhang,Wenlong Zhang,Peizhe Sun
Nitrogen, phosphorus and potassium are essential for crop growth, which are abundant in urine. Although numerous studies have developed techniques to recover ammonium and phosphorus from urine, limited research made efforts on the recovery of potassium, which is a non-renewable resource with uneven global distribution. In this study, we explored the possibility of zeolite based mixed matrix membranes (MMMs) to selectively recover ammonium and potassium from urine, with minimal detention of sodium. The findings demonstrated that upon the pre-treatment of zeolites with sodium chloride solution, a 70 wt% zeolite loaded MMM could achieve 69.3 % recovery of potassium and almost full recovery of ammonium. By varying the desorption temperatures and MMMs production process, it was discovered that stepwise backwash at low temperature (276 K) greatly lowered sodium recovery whilst simultaneously enhancing the recovery of potassium and ammonium. This study demonstrates the potential of recovering potassium and ammonium from urine using zeolite-loaded MMMs, coupled with achieving low-sodium recovery.
研究领域:
环境工程
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废水处理
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资源回收
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产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Jianwei Yuan,Chengcheng Zhou,Jiawei Zheng,Qianqian Jia,Zhenggang Wang,Haipeng Zhu,Guozhen Liu,Yanan Guo,Zhenwei Zhang,Shuping Zhang,Pin Zhou,Gongping Liu,Wanqin Jin
The membrane-based pervaporation process presents substantial promise for the challenging separation of azeotropic mixtures. However, the efficiency of conventional polymeric membranes in achieving this remains suboptimal. To tackle this issue, there has been notable attention directed towards the amalgamation of metal–organic frameworks (MOFs) with polymer matrices, giving rise to the creation of mixed matrix membranes (MMMs). In this study, for the first time, we integrated MOF-303 crystals into a chitosan (CS) matrix, thereby pioneering the development of MOF-303/CS MMMs designed for the separation of azeotropic mixtures of methanol/methyl tert -butyl ether (MTBE). By employing the spin-coating method, a thin and defect-free MOF-303/CS membrane layer was effectively deposited onto a porous substrate. The morphology and physiochemical attributes of the synthesized MOF-303 crystals and the subsequent MOF-303/CS MMMs were analyzed using techniques such as SEM, XRD, TGS, and FTIR. The separation data revealed a marked enhancement in flux and methanol permeance upon the introduction of MOF-303 crystals into the CS membrane, whereas the increase in MTBE flux and permeance was relatively few, resulting in an augmented methanol/MTBE separation factor and selectivity. The optimized MOF-303/CS MMM demonstrated outstanding and enduring separation efficacy, demonstrating a total flux of 173 g/m 2 ·h and a methanol/MTBE separation factor of 209 at 40 °C for 10 wt% methanol-MTBE mixtures. Notably, this performance surpassed that of the pure CS membrane by nearly 1.6 times in total flux and 3.68 times in separation factor, respectively, underscoring its substantial potential in the efficient separation of azeotropic mixtures.
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
SEPARATION AND PURIFICATION TECHNOLOGY
·
2018
·
IF 3.927
Xiaolong Han,Tingting Hu,Ye Wang,Huiyong Chen,Yuqi Wang,Ruiqing Yao,Xiaoxun Ma,Jiding Li,Xifei Li
In this article, ZIF-8 nanoparticles were synthesized in water and directly added to a polyethyleneglycol (PEG) aqueous solution (water-based mixing process) to prepare ZIF-8/PEG mixed matrix membranes (MMMs) for pervaporation desulfurization. The structure and properties of ZIF-8 particles were characterized by Fourier Transform-Infrared Spectroscopy (FT-IR), scanning electron microscopy (SEM), X-ray diffraction (XRD), and BET analysis. The surface composition and structural morphology of all ZIF-8/PEG MMMs were systematically investigated by FT-IR and SEM. The effect of ZIF-8 content on the pervaporation performance of ZIF-8/PEG membranes was investigated. Versus pure PEG membranes, both the total flux and the sulfur enrichment factor of the ZIF-8/PEG MMMs were remarkably increased. This phenomenon is attributed to the good compatibility between PEG and ZIF-8 particles and the high thiophene selective sorption of ZIF-8 particles (confirmed by molecular simulation). Optimal pervaporation performance was achieved at a 4 wt% loading of ZIF-8 particles with the flux of 1.96 kg/(m 2 h) and the sulfur enrichment factor of 8.93. These increased by 397.46% and 18.75% versus pristine PEG membrane, respectively. In addition, the effect of operation temperature and feed sulfur content on membrane performance were also systematically investigated.
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
SEPARATION AND PURIFICATION TECHNOLOGY
·
2016
·
IF 3.299
Xiaolu Wang,Jinxun Chen,Manquan Fang,Tao Wang,Lixin Yu,Jiding Li
In this contribution, zeolitic imidazolate framework (ZIF-7)/polydimethylsiloxane (PDMS) mixed matrix membranes (MMMs) with uniformly dispersed ZIF-7 were fabricated. The homogeneous dispersion of ZIF-7 nanoparticles in PDMS matrix and better interface compatibility were characterized by SEM and EDS. PV performance reveals that the MMMs display increased total flux and the highest separation factor occurs at 20 wt% ZIF-7 loading, which were 1689 g m −2 h −1 and 66 respectively as compared to 1080 g m −2 h −1 and 51 for pure PDMS membrane when separating 1 wt% butanol aqueous solution at 60 °C. The total flux reaches 3496 g m −2 h −1 with 80 wt% butanol in permeate for the enrichment of 5 wt% butanol solution at 60 °C. The enhanced flux may result from enlarged free volume in the polymer matrix caused by the incorporation of ZIF-7 nanoparticles. Moreover, the super-hydrophobic ZIF-7 pore channels and butanol preferential permeation may contribute to the improvement of separation factor. The result also shows that there is a 21.1% reduction of energy barrier for penetrant transportation for 20 wt% ZIF-7 filled PDMS membrane as compared to pristine PDMS membrane. A long period of pervaporation experiment was also carried out to investigate the structure stability of the ZIF-7/PDMS membrane, and the MMM remains intact during the 240 h continuous operation, which is the key to industrial application for membrane-based separation process. All above indicated that ZIF-7 is a good filler to fabricate butanol permselective pervaporation membranes for butanol separation and enrichment.
研究领域:
材料科学
·
化工分离技术
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产品关联
DOI
高影响因子
Membranes
·
2021
·Vol. 11
·期 9
·693
·
IF 4.106
Fei Guo,Bingzhang Li,Rui Ding,Dongsheng Li,Xiaobin Jiang,Gaohong He,Wu Xiao
Mixing a polymer matrix and nanofiller to prepare a mixed matrix membrane (MMM) is an effective method for enhancing gas separation performance. In this work, a unique UiO-66-decorated halloysite nanotubes composite material (UiO-66@HNT) was successfully synthesized via a solvothermal method and dispersed into the Pebax-1657 matrix to prepare MMMs for CO2/N2separation. A remarkable characteristic of this MMM was that the HNT lumen provided the highway for CO2diffusion due to the unique affinity of UiO-66 for CO2. Simultaneously, the close connection of the UiO-66 layer on the external surface of HNTs created relatively continuous pathways for gas permeation. A suite of microscopy, diffraction, and thermal techniques was used to characterize the morphology and structure of UiO-66@HNT and the membranes. As expected, the embedding UiO-66@HNT composite materials significantly improved the separation performances of the membranes. Impressively, the as-obtained membrane acquired a high CO2permeability of 119.08 Barrer and CO2/N2selectivity of 76.26. Additionally, the presence of UiO-66@HNT conferred good long-term stability and excellent interfacial compatibility on the MMMs. The results demonstrated that the composite filler with fast transport pathways designed in this study was an effective strategy to enhance gas separation performance of MMMs, verifying its application potential in the gas purification industry.Keywords:composite material;UiO-66;HNT;mixed matrix membrane;CO2/N2separation
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）