JOURNAL OF MEMBRANE SCIENCE
·
2023
·
IF 9.5
Zhenyuan Li,Tianliang Han,Wei Lai,Jie Ma,Yang Zhang,Qi Wu,Can Wang,Chunfa Liao,Shuangjiang Luo
Herein, we develop and investigate the performance of defect-free hollow fiber membranes (HFMs) based on a novel 6FDA-mPDA 0.65 -DABA 0.3 -TFMB 0.05 copolyimide for helium separation from multi-component natural gas. The copolyimide is synthesized using a two-step condensation polymerization, and the hollow fiber membranes are fabricated using a dry-jet/wet-quench spinning approach. Thermal crosslinking of hollow fiber membranes is conducted to enhance plasticization resistance. The crosslinked membranes exhibit improved He selectivity (α(He/CH 4 ) = 259) compared to the pristine hollow fiber membrane (α(He/CH 4 ) = 210). Gas permeation tests are performed on the pristine and crosslinked hollow fiber membranes using pure-gas and mixed-gas at various pressures. The results demonstrate that the crosslinked membranes effectively resist plasticization even under high-pressure gas feeds containing CO 2 , light hydrocarbons, and heavy hydrocarbons. In contrast, the uncrosslinked membranes experience plasticization, dramatically decreasing selectivity. The findings provide valuable insights into the plasticization behavior of different impurity compounds in hollow fiber membranes and highlight the potential of thermal crosslinking as an effective strategy to improve the plasticization resistance of HFMs for He recovery. These defect-free and plasticization-resistant membranes hold promise for efficient He recovery from mixed-gas streams, offering a viable and energy-efficient alternative to traditional separation methods.
研究领域:
材料科学
·
化学工程
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2024
·
IF 4.1
Yongyue Zhang,Hua Wang,Lin Li,Xiaolu Zhang,Xinyu Dong,Xiaowen Wang,Yanqiu Pan,Tonghua Wang
In this work, polyacrylonitrile (PAN) membranes were hydrolyzed with NaOH solution, and then hydrolyzed PAN (HPAN) membranes were used to prepare organic solvent nanofiltration (OSN) membranes with thermal crosslinking method. The chemical structure and pore structure evolutions of membrane during hydrolysis and thermal crosslinking were systematically investigated. The influences of hydrolysis carboxylation on permeation performances of membranes were studied in detail. Benefiting from the carboxylic groups generated by hydrolysis reaction of nitrile groups, the cyclization reaction of HPAN molecular chains was more easily initiated by ionic mechanism at a lower temperature, and the pore structure fusion of thermally crosslinked membranes was effectively inhibited. The permeances of the thermally crosslinked membranes derived from HPAN membranes were greatly improved. Furthermore, the thermally crosslinked membrane showed stable OSN performance due to the generation of ladder structure during thermal crosslinking. Therefore, the OSN membranes prepared in this work have great potential for practical applications.
研究领域:
材料科学
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化学工程
·
膜技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2021
·
IF 8.742
Liang Wang,Xiang Guo,Feng Zhang,Nanwen Li
The polybenzimidazoles (PBI) has been employed as blends and macromolecular crosslinkers into bromomethylated polymers of intrinsic microporosity (PIM-Br) to prepare anti-plasticized gas separation membrane . Interestingly, the PBI showed excellent miscibility with PIM-Br probably due to the interaction between the benzimidazole and –CN groups, and thus a series of flexible, tough and transparent membranes were obtained by simply blending. After thermal treatment of the blending membrane, the crosslinked PIM-Br/PBI membranes with ionic and covalent crosslinking were achieved as confirmed by XPS results. Although the blending PIM-Br/PBI membranes showed the decreased gas permeabilities due to the lower gas permeability of PBI moieties, the increased gas permeabilities of PIM-Br/PBI membrane has been observed after crosslinking without significant sacrificing of selectivity. Moreover, higher crosslinking temperature induced the higher gas permeability. The PIM-Br/PBI membrane having PBI content of 5 wt% treated at 300 °C has a CO 2 permeability of 3313.7 Barrer which is much higher than that of the PIM-Br/PBI blending membrane (1645.3 Barrer) probably due to the formation of more open matrix in membrane after crosslinking. However, comparable CO 2 /CH 4 selectivity of ~13 were observed for all of the crosslinked membranes. Importantly, both of the blending and thermal crosslinking between PIM-Br and PBI resulted in the excellent CO 2 anti-plasticization ability of the membrane. Particularly, a single gas plasticization pressure as high as more than 600 psi and mixed-gas plasticization resistance for crosslinked PIM-Br/PBI have been observed. This value is much higher than that of the pristine PIM-Br membrane (100 psi).
研究领域:
材料科学
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化学工程
✓ 已验证
DOI
高影响因子
Journal of Coatings Technology and Research
·
2020
·Vol. 17
·期 4
·1065-1074
·
IF 1.815
Liu Zhiqiang,Chen Hongxiang,Hu Gang,Wang Jun,Xin Yufei,Xiang Chuanxi,Zhou Yu
There is a trade-off between water resistance and mechanical properties of the waterborne polyurethane film. Aiming to solve this problem, the waterborne polyurethane-acrylate (WPUBH) was prepared by post-chain extension of dithiol instead of diamine, which could improve the storage stability and reduce the water absorption rate due to the absence of urea groups, and by terminating with hydroxyethyl acrylate, which could reduce the water absorption rate and improve the mechanical properties at the same time deriving from the crosslinking of double bonds after heating. The rate of water absorption for WPUBH-2 film decreased down to 2.87%, and the tensile strength reached 8.5 MPa. The water resistance and the mechanical properties of WPUBH obtained a good balance compared with those of the carboxylate-based waterborne polyurethane-acrylate in the previous reports. They had excellent bonding properties for wood joints, and the tensile shear strength was up to 4.53 MPa.
研究领域:
材料科学
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化学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2023
·
IF 9.5
Chao Han,Huan Liu,Yida Wang,Fuxin Zheng,Gang Han,Yan Wang
Organic solvent nanofiltration (OSN) offers an energy-efficient alternative to conventional thermal distillation processes for organic solvent separations. However, the fabrication of polymeric OSN membranes with adequate chemical stability in strong polar aprotic solvents remains a remarkable challenge. In this work, chemically robust polyamide thin-film composite (TFC) OSN membranes were fabricated by utilizing an innovative chemical modification of polyimide (PI) nanofiber substrate via one-step crosslinking and thermal cyclodehydration of terephthalic hydrazide (TPDH). The crosslinking and cyclodehydration reaction mechanisms were thoroughly elucidated and the effects of TPDH loading and thermal treatment conditions on solvent resistance and pore structure of the resulting TPDH/PI nanofiber substrates as well as the formation of the polyamide selective layer were systematically studied. The resulting TFC membranes show excellent stability in polar aprotic solvents (i.e., DMF, DMAC, and NMP), and a high DMF permeance of 9.4 L m −2 h −1 bar −1 was achieved with a 99.8% rejection to Rose Bengal at 2.0 bar. The outstanding long-term performance stability revealed the robust structure of the developed TFC OSN membranes. This work demonstrates a facile strategy to address the chemical stability limitations of TFC OSN membranes through a multifaceted yet generalizable approach of chemical crosslinking and thermal cyclodehydration. We believe this strategy can be broadly applied to different substrates, enabling TFC membranes to address a wide variety of unmet OSN needs.
研究领域:
材料科学
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化学工程
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膜技术
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产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2023
·
IF 9.5
Yuchen Zhang,Junhao Xin,Guolong Huo,Zhiguang Zhang,Xiaowei Zhou,Jicheng Bi,Shuanyan Kang,Zhongde Dai,Nanwen Li
Polyimides (PIs) have gained recognition as highly desirable membrane materials for efficient CO 2 /CH 4 separation. However, the practical utilization of these materials has been impeded by the issue of the substantial susceptibility to plasticization when exposed to high-feed-pressure conditions. Although thermal cross-linking has been widely employed to enhance plasticization resistance in PI membranes, cross-linking will normally sacrifice CO 2 permeability. Thus, the advancement of PI membranes that exhibit both remarkable CO 2 permeability and exceptional plasticization resistance is highly desired. The current work designed a series of cross-linkable PIs with different polymer chain orientation degrees. Different from conventional PIs, by properly controlling the polymer chain orientation, the CO 2 permeability can be enhanced by 2.3 times without compromising the membrane plasticization resistance. Various techniques, including FTIR, WAXD , TGA , and DMA, were employed to thoroughly characterize the obtained membranes. These characterizations verified that optimizing the polymer chain orientation constitutes an efficacious strategy to enhance the resistance of PI membranes against plasticization, while simultaneously preserving their CO 2 permeability. Additionally, the thermally cross-linked membranes exhibited good long-term stability during an 1100-h test.
研究领域:
材料科学
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化学工程
·
膜分离技术
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产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2021
·
IF 9.229
Xiaojing Lv,Jin Li,Libin Xu,Xuchen Zhu,Alexey Tameev,Alexander Nekrasov,Grigory Kim,Haofei Xu,Cheng Zhang
Transparent-to-colored electrochromic devices exhibit promising application prospects and have gained popularity. Herein, two triphenylamine derivatives TPA-OCH3 and TPA-CN with styryl moieties and different donor or acceptor units were designed and synthesized to further prepare solvent-resistant thermally cross-linking polymer P(TPA-OCH3) and P(TPA-CN) without any additional initiator. P(TPA-OCH3) and P(TPA-CN) possess two pairs of redox peaks, and P(TPA-OCH3) shows a lower onset oxidation potential compared to P(TPA-CN) because of the pendent donor unit. Correspondingly, both polymers exhibit multicolored changes from the neutral colorless state to noticeable oxidized colors under different potentials. Furthermore, the thermally cross-linking copolymer P(TPA-OCH3-co-TPA-CN) was obtained by TPA-OCH3 and TPA-CN (the molar ratio is 2:1) and presents outstanding electrochromism with four color changes (colorless–orange–blue–purple) due to the multistep redox process of TPA-OCH3 and TPA-CN units. It is more intriguing that the electrochromic device based on the copolymer films possesses a high optical contrast of 57.8% at 680 nm, fast switching time (0.52 and 0.66 s), and robust cyclic stability over 30 000 cycles with very little decay. Therefore, the thermally cross-linking copolymer is a promising candidate material for high-performance transmittive electrochromic devices, such as smart windows, sunglasses, and E-papers.
研究领域:
材料科学
·
化学
✓ 已验证
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2020
·
IF 8.247
Ming Cai,Ding Yuan,Xiao Zhang,Yi Pu,Xiaofang Liu,Hongwei He,Lixue Zhang,Xin Ning
Here, a novel PVDF-HFP/PI side-by-side bicomponent electrospun separator with cross-linked structure is successfully fabricated for lithium-ion batteries (LIBs). The bicomponent composite fiber not only integrates the excellent characteristics of PVDF-HFP and PI , but also improves the mechanical strength of the electrospun nonwoven and maintains a high level of porosity, up to 85.9 %. Moreover, the PVDF-HFP/PI(T) fibrous separator emerges outstanding performance, including the thermal dimensional stability (up to 200 °C), self-extinguishment, high electrolyte uptake (483.5 %), good ionic conductivity (1.78 × 10 −3 S/cm), wide electrochemical stability window (up to 4.94 V vs. Li + /Li) and favorable interface structure . It is further confirmed by the 3D simulation that the PVDF-HFP/PI(T) nonwoven using as the LIBs separator is beneficial to the homogeneous transmission of lithium ions . As a result, the coin cells with PVDF-HFP/PI(T) separator possess the best first discharge capacity (120.41 mAh g −1 ) and coulombic efficiency (99.36 %) with respect to that of Celgard2320 separator and cross-electrospun PVDF-HFP + PI(T) separator. After 50 cycles, the discharge capacity of Li/PVDF-HFP/PI(T)/LiFePO 4 is found to be retained around 98.13 %, which is higher than 94.91 % of Celgard2320 separator and 96.09 % of cross-electrospun PVDF-HFP + PI(T) separator. Moreover, the coin cell using the PVDF-HFP/PI (T) separator exhibited good discharge capacity under different discharge C-rate at 45 °C, indicating its potential for the high-temperature safety of LIBs. In sum, the PVDF-HFP/PI(T) nonwoven with excellent property has an application prospect in the field of LIBs separator, which also provides a reliable strategy for designing the electrospun separator with improved performance.
研究领域:
材料科学
·
能源存储技术
✓ 已验证
DOI
高影响因子
HIGH PERFORMANCE POLYMERS
·
2021
·
IF 2.161
Kai Ma,Hanzhou Jiang,Guofei Chen,Wei Wang,Yonggang Zhang
Several polyimides were prepared via two-step polycondensation from novel 2,5-furandicarboxylic acid–based diamine, 2,5-bis[4-(4-aminophenoxy)benzoyl]furan, with commercial dianhydrides. The chemical structures of the monomers and polymers were characterized by FT-IR and NMR in detail, respectively. The polyimides exhibited high performances with 5 wt% weight loss temperatures of over 410 oC, glass transition temperatures of over 214 oC, and tensile strengths and Young’s moduli of up to 130 MPa and 3.2 GPa, respectively. The thermal crosslinking mechanism was studied by FT-IR, Raman spectroscopy, and model reaction analysis, which showed the Diels–Alder reaction between the furan group and diphenylethylene group was the main reaction. The crosslinked polyimide films showed improved solvent resistance, and thermal and mechanical properties.
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
CARBOHYDRATE POLYMERS
·
2020
·
IF 7.182
Zeyu Qin,Xiwen Jia,Qian Liu,Baohua Kong,Hao Wang
In this study, electrospun chitosan/pullulan composite nanofiber films were crosslinked by two green methods (heating and cinnamaldehyde). With the increase of chitosan content, the morphology results indicated that the nanostructures of thermal crosslinking chitosan/pullulan (TCP) and cinnamaldehyde crosslinking chitosan/pullulan (CCP) nanofiber films became more stable. The decreases in weight loss (83.65 % to 43.85 % for TCP and 23.42 % to 15.58 % for CCP) and the increases in water contact angle (31.8° to 54.1° for TCP and 83.65 % to 43.85 % for CCP) confirmed the improved water stability. The decreases in water vapor permeability indicated that the crosslinking processes significantly improved the barrier properties of the films. Mechanical and thermal properties of TCP and CCP films were enhanced respectively. Furthermore, the corresponding properties of CCP films were more excellent than TCP films. FTIR results indicated the occurrence of Maillard reaction during the thermal crosslinking process and Schiff base reaction during the cinnamaldehyde crosslinking process.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF POLYMERS AND THE ENVIRONMENT
·
2022
·Vol. 31
·期 1
·131-148
·
IF 4.705
Wang Yanli,He Junwei,Sun Hong,Zou Liming,Li Yan Vivian
Hyperbranched poly (phenylalanine-lysine) (HBPL) is obtained by phenylalanine and lysine and then mixed with Polyvinyl Alcohol (PVA) polymer to electrospin PVA/HBPL fluorescent nanofiber mats (FNM), which is an excellent sensing material for Cu 2+ ions in aqueous solutions. In this work, the relationship between mechanical properties, fluorescent properties and the sensing for Cu 2+ ions of PVA/HBPL FNM are investigated. PVA/HBPL FNM with different mass ratio of PVA and HBPL are characterized by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectra, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), fluorescence spectrum and tensile tester. To further improve the water solubility of PVA/HBPL FNM, thermally cross-linking (TCL)-PVA/HBPL FNM is fabricated. The results indicate that the neat PVA FNM couldn’t emit fluorescence under any excitation wavelength, whereas the PVA/HBPL FNM emit blue fluorescence green fluorescence when the irradiation of the excitation wavelength is at 330–385 nm and 450–480 nm, respectively. The tensile strength and Young’s modulus of PVA/HBPL FNM are 8.67 MPa and 342.92 MPa, respectively, which suggested 43.1% and 242.7% than that of neat PVA NM. Furthermore, the solubility rate of TCL-PVA/HBPL FNM is significantly decreased in comparison of FNM in absent of cross-linking. It’s worth noting that TCL-PVA/HBPL FNM possessed higher recognition than other mental ions and could be used as metal ion detection sensor to combine with Cu 2+ . Moreover, it represented a linear relationship between the fluorescence intensity and the concentration of Cu 2+ in the range of 5 µM to 100 µM. The fabricated TCL-PVA/HBPL FNM exhibit high mechanical and fluorescence properties, which make it be potentially envisaged for heavy metal ions detection sensor.
研究领域:
材料科学
·
分析化学
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产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2023
·Vol. 59
·期 2
·728-741
·
IF 4.5
Zhang Yongyue,Li Lin,Wang Hua,Wang Xiaowen,Pan Yanqiu,Wang Tonghua
In this work, in situ sol–gel strategy was used to introduce silica gel in polyacrylonitrile (PAN) membrane pores, by which the pore structure of organic solvent nanofiltration (OSN) membrane prepared with thermal crosslinking was maintained well. The chemical structure, microstructure and morphology changes of membrane during sol–gel and thermal crosslinking were systematically studied by FTIR, XPS, XRD and SEM. Benefitting from the introduction of silica gel, the fusion of membrane pore structure during thermal crosslinking was effectively inhibited by supporting the pore with silica gel. Therefore, the permeances of the thermally crosslinked membranes supported by in situ silica gel were greatly improved. Furthermore, the thermally crosslinked membrane showed excellent stability of OSN performance due to the generated ladder structure of membrane during thermal crosslinking. This work showed that in situ silica gel supporting is a promising strategy to stabilize the pore structure of PAN membrane during thermal crosslinking.
研究领域:
材料科学
·
化学工程
·
膜技术
✓ 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）