SEPARATION AND PURIFICATION TECHNOLOGY
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2026
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IF 9.1
Shibo Zhao,Xinjun Wen,Hongge Jia,Mingyu Zhang,Yanqing Qu,Chengbao Geng
The continuous increase in greenhouse gas emissions is having a significant impact on the global climate system. To address this issue, efforts worldwide are promoting the development of clean energy source, with methane-rich biogas being a primary focus. However, the dilution of biogas with CO₂ significantly reduces its calorific value. Therefore, efficient methane purification and resource utilization are urgently required. This study specifically developed a high-efficiency gas separation membrane suitable for large-scale industrial applications. By precisely separating CO₂ from biogas, it provides crucial technological support for enhancing biogas energy quality and promoting its industrialization. Specifically, using a conventional polyimide membrane (6FDA-APAF) as the template, a series of intrinsically microporous polyimide membranes (PIM-PI membranes) were innovatively synthesized by incorporating fluorene-containing microporous units—Namely, 9,9′-bis(4-aminophenyl)fluorene (FDA) or 9,9′-bis(4-amino-3-fluorophenyl)fluorene (FFDA). Subsequent thermal rearrangement (TR) treatment produced PIM-PI(TR) membranes. Both the introduction of fluorene groups and TR treatment increased the interchain spacing of the membranes, with the thermally rearranged PIM-PI(TR) membranes exhibiting larger d-spacings and broader micropore peaks. The 6FDA-FFDA (PIM-PI membrane) achieved a CO₂ permeability coefficient of 151.87 barrer, which is 9.9 times higher than that of the nonporous conventional polyimide membrane (6FDA-APAF, 15.4 barrer). The 6FDA-APAF/FDA (8,2) TR400 [PIM-PI(TR) membrane], subjected to thermal rearrangement, further increased its CO₂ permeability coefficient to 813.80 barrer, representing a 19-fold improvement over the untreated membrane. Simultaneously, this membrane exhibited a CO₂/CH₄ permeability selectivity factor as high as 39.03, surpassing the 2019 Robeson upper bound. Furthermore, both macro- and micro-characterizations reveal structurally uniform and intact membranes. With superior fabrication quality that lays a solid foundation for industrial applications. These results highlight the promising potential of TR-treated PIM-PI (TR) membranes containing fluorene-based pore-forming units for gas separation. This study also offers essential technical support for the industrial application of polyimide membranes in biogas purification
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DYES AND PIGMENTS
·
2025
·
IF 4.2
Shanting Liu,Xi Kang,Bumeng Guo,Zewei Song,Shuang Li,Yinghan Li,Sheng Hua Liu,Zhao Chen
Due to their distinctive stimulus-responsive properties, materials exhibiting hypsochromic mechanofluorochromism (MFC) or force-induced substantial weakening of fluorescence intensity have demonstrated remarkable application potential in the field of information security. This study designed and synthesized two novel fluorene-based dinuclear gold(I) complexes, 1 and 2 . Both molecules exhibited aggregation-induced emission (AIE) characteristics. Specifically, complex 1 showed reversible hypsochromic MFC. In contrast, complex 2 exhibited force-induced substantial weakening of fluorescence intensity. It is worth noting that 2 is the first example of gold(I)-based luminogen capable of simultaneously exhibiting AIE and force-induced substantial weakening of fluorescence intensity. Based on the force-induced significant fluorescence attenuation feature of luminogenic complex 2 , an interesting information anticounterfeiting system involving a pizza model was successfully established. This work not only reports the first example of AIE-active gold(I) complex featuring anisotropic mechanical force-induced pronounced fluorescence reduction but also provides a valuable reference for anticounterfeit applications of mechanically responsive luminogens.
研究领域:
材料化学
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超分子化学
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发光材料
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智能响应材料
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防伪技术
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高影响因子
JOURNAL OF POLYMER SCIENCE
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2024
·
IF 3.9
Lei Yang,Jinglei Xing,Minghui Bai,Xingzhong Fang,Guofei Chen
Transparent polyimides were expected to be an alternative to glass substrates. To meet the requirements of high transparency, high heat resistance, and low coefficients of thermal expansion (CTE) for substrate materials, a series of poly(amide-imide)s (PAIs) were synthesized from 2,2′-bis(trifluoromethyl)benzidine (TFDB), (hexafluoroisopropylidene)diphthalic anhydride (6FDA), cyclobutane-1,2,3,4-tetracarboxylic dianhydride (CBDA), terephthaloyl chloride (TPC) and 9,9-bis(4-aminophenyl)fluorene (FDA) with different substituents. And the corresponding films were prepared by adding 0 or 2 pph lithium chloride (LiCl). Through the adjustment of monomer ratio, regulation of the amino ortho -position of diamine monomer, and coordination of Li ions, all PAIs exhibited high glass transition temperatures ( T g ) of 390°C–436°C, low CTE of 12.5–60.9 ppm K −1 , excellent optical transmittances of 71%–84% at 400 nm, high tensile strengths of 140–204 MPa, and high tensile moduli of 4.4–7.2 GPa. In particular, PAI-M-1-2-2Li showed the best comprehensive properties with the transmittance of 83% at 400 nm, T g of 432°C, CTE of 18.7 ppm K −1 , tensile modulus of 6.9 GPa and tensile strength of 204 MPa, which made it competitive in flexible display applications. Graphical
研究领域:
材料科学
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高分子化学
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Chemosensors
·
2023
·Vol. 11
·期 1
·53
·
IF 4.2
Xiang-Dong Qing,Xiao-Hua Zhang,Rong An,Jin Zhang,Ling Xu,Ludovic Duponchel
Human activity today produces a large number of pollutants that end up in the environment, such as soil, water, and airborne particles. The first objective of this work is to introduce a new third-order multivariate calibration approach called self-weighted alternating quadrilinear decomposition (SWAQLD) for the analysis of organic pollutant of fluorene (FLU) in different water systems. One simulated and two real four-way data sets are used to study the potential of the proposed approach in comparison with two classical algorithms, namely alternating quadrilinear decomposition (AQLD) and parallel factor analysis (PARAFAC). The results of simulated data show that SWAQLD inherits the advantages of PARAFAC in terms of not only tolerance to experimental noise but also a fast convergence and a certain robustness to overestimation of the rank of the models from AQLD. The second objective of this work is to propose a new way of generating third-order data using excitation–emission matrix phosphorescence (EEMP) at room temperature for the study of the kinetic process of oxidation of FLU in complex chemical systems. The obtained rate constant and half-life of the FLU oxidation, on average, are 0.015 min−1and 45.5 min for free-interference water and 0.017 min−1and 40.0 min for wastewater, respectively. Research results show that SWAQLD coupled with EEMP allows the quantification and kinetic monitoring of FLU in analytical conditions of different complexities with excellent robustness to the choice of the number of model components.Keywords:third-order multivariate calibration;SWAQLD;AQLD;PARAFAC;phosphorescence;fluorene;wastewater
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