MACROMOLECULES
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2023
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IF 5.5
Yu Zhang,Junming Dai,Hua Lai,Yinhua Wan,Young Moo Lee,Yongbing Zhuang
The development of proton exchange membrane fuel cells (PEMFCs) that operate over a wide temperature range without additional humidification systems remains challenging. In this work, wide-temperature-range proton exchange membranes (PEMs) were constructed from novel Tröger’s base (TB)-based intrinsically microporous copolyimides (co-PIs) finely adjusted by incorporating crown ether units into chain backbones. Owing to the strong siphoning effect of existing microporosity and hydrogen bonds or the acid–base interactions of crown ether and TB units with phosphoric acid (PA) and/or H2O, the PA-doped co-PI membrane electrode assemblies (MEAs) can easily operate stably from 30 to 160 °C under H2/air conditions even without any external humidifiers. Regarding its single-cell performance, PI-TB-N30C achieved maximum power densities of 250 and 361 mW cm–2 at 80 and 160 °C, respectively, under anhydrous conditions. In addition, PA-doped co-PI MEA can accomplish long-term stable operation under low or high temperatures for 120 h. The structural architectures for PEMs based on finely adjusted microporous co-PIs extend beyond the current capabilities of existing PEMFCs.
研究领域:
材料科学
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能源工程
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2024
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IF 8.1
Bingyu Zhao,Haojie Li,Zian Chen,Jiawei Lin,Yaodong Liu
The potential of carbon molecular sieve membranes (CMSM) for gas separation is widely recognized, and the key precursor for these membranes is polyimide (PI). This study focuses on enhancing the gas separation properties of CMSMs by introducing a unique structural element, Tröger’s bases, into polyimides, resulting in the creation of five distinct polyimides containing Tröger’s bases (PI-TBs). The incorporation of Tröger’s bases has a profound impact on the arrangement of polymer chains within the PIs, leading to a substantial improvement in gas permeability without compromising selectivity. Following carbonization at 600 °C, the resultant CMSMs exhibit significantly enhanced gas permeability while preserving, and in some cases, improving gas selectivity. Among the various types of diamines considered, the 6FDA variant of PI-TB stands out, boasting outstanding gas permeability with a H 2 permeability of 4991.0 Barrer and a H 2 /CH 4 selectivity of 30.7; this level of performance surpasses the 2015 Robeson’s upper bound. Furthermore, thermal analysis coupled with mass spectrometry (TG-MS) reveals that the pyrolysis of Tröger’s bases commences prior to that of polyimide . This sequential degradation process facilitates the formation of pyridine N and promotes the π-stacking of PI chains; both of which are instrumental in maintaining excellent gas selectivity. These findings provide valuable insights into the roles of Tröger’s bases in enhancing the gas separation performance of PIs and CMSMs, offering a promising avenue for further advancements.
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
MACROMOLECULES
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2025
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IF 5.2
Mengtao Wang,Luxin Sun,Chen Luo,Jiachen Chu,Congcong Wu,Kunying Li,Xuepeng Li,Kai Song,Jianxin Li,Xiaohua Ma
Formation of porous organic polymer (POP) membranes is a great challenge due to their highly cross-linked nature that prevents film formability. Here, we reported a series of mechanically strong POP membranes derived from a cross-linked Tröger’s base using 3,3′-dimethylbiphenyl-4,4′-diamine as a linear monomer and 1,3,5-tris(4-aminophenyl)benzene (TPB) as a cross-linking node. As the TPB content increased from 0% (TPB-0) to 75% (TPB-75), these POP membranes show a continuously decreased chain spacing from 7.96 to 6.22 Å, increased Brunauer–Emmet–Teller surface areas from 250 to 531 m2 g–1, and enhanced ultramicropore volumes from 0.046 to 0.143 cm3. Thereby, a huge increase in permeability without sacrificing selectivity was observed for these TPB-based POP membranes. For example, TPB-75 exhibited not only over 19 times larger O2 permeability (790 vs 50.3 Barrer) but also slightly higher O2/N2 selectivity (4.8 vs 4.5) than the linear TPB-0. The overall separation performances quickly improved from below the 2008 trade-off curves for TPB-0 to near the latest 2015 curves for O2/N2, H2/N2, and H2/CH4 as the TPB content increased. These results are attributed to the significantly improved ultramicroporosity that enhanced the molecular sieving effect by the POP structure induced by in situ cross-linking. This design protocol and the POP membranes provide a novel direction for advanced gas separation membranes.
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
CHEMICAL ENGINEERING SCIENCE
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2024
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IF 4.1
Xueting Zhao,Qingqing Qiu,Jinshan Sun,Xinhao Cheng,Lifen Liu,Jiefeng Pan
Nanofiltration (NF) membrane technology serves as an efficient method for separation and purification, playing a vital role in various industrial fields such as water treatment, food processing, and pharmaceutical manufacturing. However, there are still drawbacks, such as limited flux due to densely crosslinked composite layer and poor stability in solvents. In this study, we report the fabrication of the thin-film composite (TFC) NF membrane using Tröger’s base-derived building block, aiming to manipulate intrinsic pore structures of the as-synthesized ultra-thin composite layer by introducing rigid dihedral units. The interfacial polymerization process is employed to enable the polycondensation of Tröger’s base-based diamine monomer and tri-aldehyde monomer via Schiff base reaction. The effects of monomer concentration, immersion time, interfacial polymerization reaction time, heat treatment time and temperature on the performance of NF membrane were studied. The optimized NF membrane presents a rejection of Methyl blue (MB) above 95.3 % and achieves a high water permeance of 43.4 L·m −2 ·h −1 ·bar −1 . The water permeance is 2–3 times higher than the reported NF membranes with similar rejection ability. In addition, Tröger’s base-derived TFC NF membrane exhibits excellent long-term stability and good organic solvent tolerance. Considering the high water permeance and separation efficiency, the present membrane has significance in dye removal and separation processes.
研究领域:
材料科学
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环境工程
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
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2025
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IF 4.3
Yongchao Sun,Xudong Bi,Lu Bai,Tianyou Li,Fangxu Fan,Zeyuan Gao,Yijun Liu,Jianyu Guan,Fake Sun,Hongjin Li,Gaohong He,Canghai Ma
Membrane separation technology holds great potential for CO 2 capture and H 2 separation due to its simplified process, low energy consumption, and environmental benefits. Consequently, there is a pressing demand for membranes with ultra-high gas separation performance that can surpass the Robeson upper bound. To address this challenge, mixed matrix membranes (MMMs) were designed by combining rigid bridging ring polymer-Tröger’s base (TB) polymer with UiO-66 or UiO-66-Br to enhance gas separation properties of membranes. DFT calculations reveal that the interaction energy between UiO-66-Br ligands and TB is significantly lower than that of UiO-66 ligands with TB, suggesting the stronger interaction between the UiO-66-Br and TB polymer. The addition of UiO-66-Br enhances gas separation performance by providing additional gas transport pathways and increasing molecular sieving through its optimized pore size and functional groups. As a result, MMMs with a 40.0 wt% MOF loading exhibit CO 2 and H 2 permeabilities of 764.4 and 1127.8 Barrer, respectively, along with CO 2 /CH 4 , CO 2 /N 2 , H 2 /CH 4 , and H 2 /N 2 selectivities of 15.6, 19.1, 23.0, and 28.2, surpassing the 2008 Robeson upper bound. Compared to TB membranes, the permeability of H 2 and CO 2 in the MMMs increased by over 247% and 222%, demonstrating exceptional gas separation performance. The design approach in this study offers an effective pathway for fabricating MMMs with high gas separation performance for efficient CO 2 capture and H 2 separation.
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
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2022
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IF 4.326
Zan Chen,Zongping Hong,Hong Wu,Cheng Li,Zhongyi Jiang
Hybrid membranes based on the Tröger’s base polyimide (PI-TB) as a rigid microporous polymer matrix containing a kinked N-heterocycle and a kind of CO2-philic porous UiO-66-NH2 nano-filler were successfully fabricated for gas separation. This new hybrid membrane exhibits good interfacial compatibility through hydrogen bonds and charge transfer interactions between the PI-TB matrix and the UiO-66-NH2 nano-filler, thus enabling a relatively high loading and well dispersion of nano-filler. Meanwhile, the as-synthesized UiO-66-NH2 nanoparticles increase the average inter-chain spacing distance of PI-TB by interfering with the packing of polymer chains and thus providing additional transport pathways in the membranes. The pure gas permeabilities and ideal selectivities for CO2/CH4, CO2/N2, and O2/N2 systems were investigated at 35 °C and a feed pressure of 1 bar. Among them, the hybrid membrane containing 30 wt % UiO-66-NH2 exhibits the optimal gas separation performance with enhanced permeabilities of CO2 and O2 increased by ∼166% (415 and 92.3 Barrer, respectively) while maintaining comparable CO2/CH4, CO2/N2, and O2/N2 gas pair selectivities (25.0, 18.9, and 4.2, respectively) with the pristine PI-TB membrane. This work enriched the studies on the post-modification of PI-TB as a potential candidate membrane material for gas separation.
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
危险品化学品经营许可证（带存储）