JOURNAL OF POWER SOURCES
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2023
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IF 9.2
Hongying Tang,Ge Chao,Jian Gao,Yuntao Shang,Nanwen Li,Kang Geng
To further mitigate the phosphoric acid leakage in high temperature proton exchange membrane (PEM), the microporosity of Tröger's base (TB) membrane based on a V-shaped bridged bicyclic diamine has been fine-tailored readily by polymeric blending with a miscible polymer of intrinsic microporosity (PIM-1). As expected, the average cavity radius in the range of 3.46–4.21 Å has been achieved when the blending ratio of PIM-1 increases from 5 to 20 mol% due to the interaction between the amine group of TB and the nitrile group of PIM-1. The resulting PEMs show excellent PA retention ability. Notably, PIM/TB9 membrane with a suitable cavity radius of 3.5 Å and largest FFV 4 of 49.1% exhibits an exciting PA retention of about 80%, which is much better than the pristine TB membrane. Thus, the remaining proton conductivity of PIM/TB9 is almost 5 times higher than that of TB membrane after 22 relative humidity cycle tests. Moreover, the resulting cell can run smoothly within a wide temperature range from 0 to 160 °C. The single cell performs for over 150 AST cycles and remains stable for >600 h with no visible voltage decay at 80 °C. Therefore, these results indicate the technical feasibility to improve the PA retention via fine-tuning the intrinsic microporosity of the PEMs through a direct blending method.
研究领域:
材料科学
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化学工程
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高影响因子
CHINESE JOURNAL OF CATALYSIS
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2023
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IF 16.5
Nan Yin,Weibin Chen,Yong Yang,Zheng Tang,Panjie Li,Xiaoyue Zhang,Lanqin Tang,Tianyu Wang,Yang Wang,Yong Zhou,Zhigang Zou
The overall photocatalytic conversion of CO 2 and H 2 O to fuel and O 2 is challenging. In this study, a series of three-dimensional Tröger's base-derived porous aromatic frameworks (3D- X -TB-PAFs ( X = TEPE, TEPM, SPF)) featuring designated reaction sites and unique charge transfer properties were developed. The incorporation of V-shaped Tröger's base (TB) units and aromatic alkynes imparts the polymers with permanent porosity, additional photon scattering cross-sections, and enhanced CO 2 adsorption/activation capabilities. Density functional theory calculations and optoelectronic measurements revealed the formation of intramolecular built-in polarization and electron-trap sites induced by TB, which modulated charge separation and customized reaction sites in collaboration with 3D networks. In addition, product allocation during the photoreduction of CO 2 was regulated by the photooxidation of H 2 O. Among the as-prepared 3D-PAFs, the most efficient electron transport channel was demonstrated by the TEPE-TB-PAF with fully conjugated TEPE-T. In the absence of cocatalysts and sacrificial agents, TEPE-TB-PAF exhibits a competitive CO formation rate (194.50 μmol g −1 h −1 ) with near-unity selectivity (99.74%). Significantly, the low energy barrier for CO desorption and the high energy barrier for *CHO formation contribute to the high efficiency of TEPE-TB-PAF, as demonstrated by computational exploration and in situ diffuse reflectance infrared Fourier transform spectra. This work offers efficient building blocks for the synthesis of multifunctional organic photocatalysts and groundbreaking insights into the simultaneous enhancement of photocatalytic reactivity and selectivity.
研究领域:
材料科学
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环境科学
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高影响因子
ChemSusChem
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2018
·Vol. 11
·期 5
·916-923
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IF 7.411
Zhenggong Wang,Huiting Ren,Shenxiang Zhang,Feng Zhang,Jian Jin
Graphical Just touching base : New carbon molecular sieve (CMS) membranes are fabricated with the use of a Tröger's base (TB)-based microporous polyimide as the polymer precursor, and their gas-separation performance is investigated. The comprehensive gas-separation performance of the TB–CMS membranes is improved relative to that of most state-of-the-art CMS membranes derived from common polyimides reported so far. Carbon molecular sieve (CMS)-based membranes have attracted great attention because of their outstanding gas-separation performance. The polymer precursor is a key point for the preparation of high-performance CMS membranes. In this work, a microporous polyimide precursor containing a Tröger's base unit was used for the first time to prepare CMS membranes. By optimizing the pyrolysis procedure and the soaking temperature, three TB–CMS membranes were obtained. Gas-permeation tests revealed that the comprehensive gas-separation performance of the TB–CMS membranes was greatly enhanced relative to that of most state-of-the-art CMS membranes derived from polyimides reported so far.
研究领域:
材料科学
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化学工程
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PubMed
高影响因子
JOURNAL OF MEMBRANE SCIENCE
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2023
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IF 9.5
Peijun Zheng,Wei Xie,Zhili Cai,Yang Jiao,Ying Sun,Tianliang Han,Xiaohua Ma,Nanwen Li,Shuangjiang Luo
Tröger's base (TB) polymer of intrinsic microporosity has aroused increasing attention in various membrane-mediated gas separations. Herein we report macromolecular engineering to tune the microporosity of Tröger's base polymer of intrinsic microporosity (TB-PIM) via ionization for highly permselective helium recovery from natural gas. We reveal that the ionization of TB-PIM tightens polymer chain-packing, leading to dramatic enhancement of gas selectivities. Consequently, the ionic ITB-PIM membranes display the He/CH 4 selectivity increments in the range of 34–158% and impressively high gas selectivities for helium recovery (i.e., α(He/CH 4 ) = 246; α(He/N 2 ) = 229). Due to the enhancement of inter-chain interactions induced by electrostatic interaction , the ITB-PIM membranes exhibit enhanced plasticization resistance compared to the pristine TB-PIM membranes. Notably, the ITB-Trip membrane showed excellent low-temperature gas separation performance with a He permeance of 3162 Barrer and He/CH 4 selectivity of 38.5 at −30 °C, far beyond the 2008 upper bound. It is also proved that the microporosity and gas separation performance of ITB-PIM membranes is highly tailorable by adjusting the TB monomer structure. The facile functionalization method, highly diverse tunability, and excellent gas separation performance render the ITB-PIM membranes promising for helium recovery from natural gas.
研究领域:
材料科学
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化学工程
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高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2024
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IF 8.1
Zhuoyi Huang,Junbo Yue,Shuzheng Sun,Feichao Wu,Jingde Li,Gang Li,Nanwen Li,Yanqin Yang
The typical procedure used to fabricate mixed matrix membranes (MMMs), where the pre-obtained filler and polymer are simply mixed together before casting, often suffers from limited polymer-filler adhesion. Herein, we prepare a series of novel MMMs with improved interfacial compatibility by preparing the matrix (Tröger’s base polymer, TB) and the filler (three-dimensional Tröger’s base-bridged porous network, 3D-TB) under the same reaction system, where in-situ crosslinking reaction between them happens simultaneously. Thanks to the excellent interfacial miscibility, the as-developed 10 wt%_3D-TB@TB membrane shows the tensile strength and elongation stain at break of 65.4 MPa and 10.12 %, respectively, which are higher than those of its counterpart synthesized by conventional procedure (55.82 MPa and 7.05 %, respectively). More importantly, both the gas permeability and selectivity of the in-situ crosslinked MMMs show an obvious improvement involving CO 2 /N 2 , CO 2 /CH 4 , and O 2 /N 2 separation. Specifically, for O 2 /N 2 binary gas separation, the 10 wt%_3D-TB@TB membrane displayed a O 2 permeability of 53.2 Barrers and O 2 /N 2 selectivity of 6.1, which are improved by 72 % and 45 % in comparison to the unfilled membrane, overcoming the 2008 Robson upper bound. Moreover, the physical aging of the in-situ crosslinked MMMs is also effectively controlled. These results demonstrate that the in-situ polymerization and crosslinking is an outstanding approach for the construction of defect-free MMMs with enhanced gas separation performances.
研究领域:
材料科学
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化学工程
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高影响因子
Journal of Materials Chemistry A
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2018
·Vol. 6
·期 27
·13302-13311
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IF 9.931
Chuan Hu,Qiugen Zhang,Chenxiao Lin,Zhen Lin,Ling Li,Faizal Soyekwo,Aimei Zhu,Qinglin Liu
Polymers of intrinsic microporosity (PIMs) represent a novel class of membrane materials attracting much attention over the past decade. But challenges still exist in the preparation of anion exchange membranes (AEMs) due to their poor solubility and brittleness. Here we present a new strategy to synthesize soluble PIMs for high performance AEMs. By combining merits of two Tröger's base units, the synthesized copolymer exhibits good solubility as well as excellent mechanical properties. The copolymer has good solubility in dimethylsulfoxide (DMSO) after little quaternization and thus permits crosslinking with a long-flexible multi-cation agent. The resulting membrane has good dimensional stability (20.8% swelling ratio at 60 °C) and excellent alkaline resistance. Subsequently, this membrane exhibits a high hydroxide conductivity of 103.9 mS cm−1 (80 °C) at a low ion exchange capacity (IEC) of 1.67 meq g−1. Moreover, this membrane achieves a peak power density of 158 mW cm−2 in a single fuel cell at a current density of 330 mA cm−2 at 60 °C. The presented approach is beneficial for developing high performance PIM-based AEMs and highlights the tremendous potential of multi-cation cross-linked Tröger's base AEMs for wide application in energy and separation fields.
研究领域:
材料科学
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化学工程
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能源技术
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高影响因子
危险品化学品经营许可证（带存储）