CHINESE JOURNAL OF CHEMISTRY
·
2015
·Vol. 33
·期 8
·939-947
·
IF 1.578
Guo-Feng Zhang,Tao Chen,Ze-Qiang Chen,Matthew P. Aldred,Xianggao Meng,Ming-Qiang Zhu
We have synthesized a series of fluorene-based fluorophores, in which a central fluorene core has been modified with different peripheral arylene vinylene substituents that are able to activate aggregation-induced emission (AIE) characteristics. 9,9-Dioctylfluorene doubly end-capped at the 2,7-positions with triphenylethene groups, such as 4-(2,2-diphenylvinyl)phenyl (F1-(2,2)-HTPE) and 4-(1,2-diphenylvinyl)phenyl (F1-(1,2)-HTPE) were synthesized and compared to the tetraphenylethene analogue (F1-TPE). Both F1-(2,2)-HTPE and F1-(1,2)-HTPE glow with a deep blue fluorescence in THF solution with emission maxima ( λ em ) of 426 and 403 nm, respectively. The λ em slightly red-shifts in the solid-state to 458 nm for F1-(2,2)-HTPE and 437 nm for F1-(1,2)-HTPE. The fluorescence quantum yields ( ø F ) of F1-(2,2)-HTPE ( ø F =35.1 %) and F1-(1,2)-HTPE ( ø F =26.2%) were found to be higher in solution compared to the near quenching of F1-TPE ( ø F =0.1%). Consequently, this results in weaker AIE-stability of F1-(2,2)-HTPE ( α AIE =1.5) and F1-(1,2)-HTPE ( α AIE =1.9) compared to F1-TPE ( α AIE =125), suggesting that four phenyl groups are necessary for efficient AIE-activity of these fluorene bridged arylene vinylene type materials. In addition, decreasing the steric hindrance around the arylene vinylene moiety by removal of a phenyl ring is another method to decrease the AIE characteristics, in a similar manner to the commonly known "phenyl-locking". Non-polar triphenylethenes are poorer AIE materials than their tetraphenylethene analogues. Replacing the hydrogen atom of F1-(2,2)-HTPE with a cyano group affords fluorene end-capped with 2,3,3-triphenylacrylonitrile (F1-TPAN), which boosts the AIE-effect to α AIE =90.5 and red-shifts the solid-state emission ( λ em =528 nm) with near quenching in THF solution ( ø F =0.12%). X-ray crystallographic analysis of F1-TPAN indicates that the introduction of cyano groups can not only diminish the intramolecular steric hindrance in comparison of F1-TPE, but also improve the molecular cohesion ability via multiple C H···N interactions.
研究领域:
有机化学
·
材料科学
·
光学
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DOI
高影响因子
INORGANIC CHEMISTRY
·
2023
·
IF 4.6
Suting Xu,Yanchen Huo,Xiang Hu,Fei Wang,Li Pan,Xiaochao Shi
As indenyl-derivates, the tetrahydrofluorenyl ligands had an expanded “wingspan” with considerable steric hindrance. In this text, the rare-earth metal complexes bearing tetrahydrofluorenyl ligands have been synthesized and fully characterized by NMR (1H and 13C) and X-ray diffraction analyses. Upon the activation by [Ph3C][B(C6F5)4], all the scandium complexes exhibited excellent catalytic activity for highly syndioselective polymerization of styrene with a narrow molecular weight distribution (Mw/Mn < 2.0), suggesting the beneficial influence of tetrahydrofluorenyl ligands in stabilizing the single-site active species during the polymerization. Moreover, the scandium-based catalytic systems also promoted the 1,4-regular polymerization of butadiene and its copolymerization with styrene, affording diblock copolymers featuring a highly syndiotactic polystyrene block and a 1,4-specific PBD block. The kinetics investigation revealed the huge gap in TMS-Sc-catalyzed polymerization reactivity ratios (rBD/rSt > 300) between butadiene and styrene, and this further proved the block structure of styrene–butadiene copolymers. The morphology and mechanical property of the selected diblock copolymer were, respectively, investigated by atomic force microscopy and stress-strain experiments.
研究领域:
有机化学
·
高分子化学
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产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2023
·
IF 7.2
Ao Nan Lai,Pei Zhi Zheng,Shu Chun Li,Yi Fei Zhu,Peng Cheng Hu,Shu Feng Zhou
A new approach is presented here for constructing higher-performance anion exchange membranes (AEMs) by combining block-type and comb-shaped architectures. A series of quaternization fluorene-containing block poly (arylene ether nitrile ketone)s (QFPENK-m-n) were synthesized by varying the length of hydrophobic segment as AEMs. The well-designed architecture, which involved grafting comb-shaped C10 long alkyl side chains onto the block-type main chains, formed efficient ion-transport channels, as confirmed by atomic force microscopy . As a result, the AEMs showed high hydroxide conductivities in the range of 34.3–102.1 mS⋅cm −1 from 30 to 80 °C at moderate ion exchange capacities (IECs). Moreover, the hydrophobic segment with nitrile groups also exhibited a profound anti-swelling property for the AEMs, resulting in ultralow swelling ratios ranging from 4.7% to 7.1% at 30 °C and 7.5%–9.8% at 80 °C, as well as superb conductivity-to-swelling ratios at 80 °C. In addition, the AEMs displayed good mechanical properties , thermal and oxidative stability , and optimizable alkaline stability.
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 JOURNAL
·
2023
·
IF 15.1
Yichang Ma,Lingjing Li,Xueqing You,Huiting Lin,Guiqin Yi,Xiangyu Su,Aimei Zhu,Qinglin Liu,Qiugen Zhang
Durable and high-performance anion exchange membranes (AEMs) are a pivotal issue for the industrial application of AEM water electrolysis (AEMWE). In this study, a series of poly(fluorenyl alkylene) copolymers with different contents of biphenyls and p -terphenyls are synthesized for the high-performance AEMWE. The resulting AEM with an appropriate content of p -terphenyl well facilitates the microphase separation to get a well-defined microstructure that effectively improves the ionic conductivity and reduces the swelling ratio. The AEM with 20% p -terphenyl possesses an OH – conductivity of 155.7 mS cm −1 , a water uptake of 128.7%, and a swelling ratio of 33.8% at 80 °C. Moreover, it also shows durable alkaline stability and retains 83.5% of cationic groups after immersing in 5 M NaOH at 80 °C for 1440 h. The assembled AEMWE cell achieves an excellent current density of 4.9 A cm −2 at 2 V in 1 M KOH (80 °C) and 2200 h of long-term constant current (1 A cm −2 ) operation with a low voltage rising rate of 77 μV h −1 . After this long-term operation, only 13.7% of cationic groups are degraded in the AEM, showing excellent in-situ durability. Therefore, the developed AEMs should have great potential for applications in the AEMWE.
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
SENSORS AND ACTUATORS B-CHEMICAL
·
2018
·
IF 5.667
Bin Qiao,Yansong Li,Pan Hu,Yu Sun,Zhaozhao Si,Shiying Lu,Honglin Ren,Zengshan Liu,Ying Zhang,Lei Meng,Yu Zhou
Fluorene is a priority pollutant in water listed by U.S. Environmental Protection Agency. A fluorescent probe using Eu(III)-marked polystyrene nanoparticles (EuNPs) labelled with a monoclonal antibody (MAb) was synthesized and an immunochromatographic assay (ICA) based on the probe (EuNPs-MAb) was developed for rapid and sensitive detection of fluorene in water samples. The concentration of fluorene was inversely proportional to fluorescence intensity values of T-line in the range 0.98–62.50 ng/mL. The limit of detection (LOD) for quantitative detection of fluorene was 0.09 ng/mL. Recoveries of fluorene in various water samples ranged from 81.50% to 103.00% and coefficients of variation (CVs) were below 13%, which were in a good agreement with those of traditional ELISA (R 2 = 0.99). The assay can be performed within 30 min. The integrated ICA strip gave higher sensitivity and reliable reproducibility. It could be a potential method for rapid and sensitive detection of fluorene in water samples.
研究领域:
环境科学
·
分析化学
·
生物医学工程
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产品关联
DOI
高影响因子
RSC Advances
·
2024
·Vol. 14
·期 25
·17771-17779
·
IF 3.9
Tao Lu,Wei Fang,Qian Zhou,Mengjuan Liu,Guozhang Wu
This study aims to synthesize a specific type of polycarbonate with high refractive index, low birefringence, and resistance to hygrothermal aging by copolymerizing 2,2′-bis(2-hydroxyethoxy)-1,1′-binaphthyl (BNE) with 9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene (BPEF). Comparative analysis revealed that the copolymer synthesized from BNE and BPEF demonstrated superior hydrolytic stability relative to the bisphenol A-based polycarbonate. This augmented stability can be attributed to the monomers' higher pKa values, rendering acidic substances less capable of dissociating and thereby mitigating ester hydrolysis under hygrothermal conditions. Furthermore, the investigation probed into the phenomenon of physical aging in copolymerized polycarbonate when exposed to hygrothermal environments. It was discerned that the enthalpy loss, observable under both dry and hygrothermal conditions, could be linearly correlated with the difference between the aging temperature and the glass transition temperature (Tg), signifying a close correlation between the magnitude of physical aging and Tg. A lower Tg in the copolymerized polycarbonate led to more pronounced physical aging within the same timeframe, resulting in an augmentation of tensile strength and modulus, while higher Tg effectively mitigated the physical aging phenomenon.
研究领域:
材料科学
·
化学工程
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DOI
高影响因子
RSC Advances
·
2017
·Vol. 8
·期 1
·194-205
·
IF 3.108
Bo Deng,Shujiang Zhang,Chang Liu,Wei Li,Xiangdong Zhang,Hua Wei,Chenliang Gong
A series of organo-soluble, high glass transition temperature (Tg), and low dielectric constant aromatic polyimides containing 4,5-diazafluorene in the polymer chain were synthesized from a novel dianhydride monomer, 9,9-di[4-(3,4-dicarboxyphenoxy)phenyl]-4,5-diazafluorene dianhydride. The introduction of 4,5-diazafluorene units improved the solubility of aromatic polyimides in commonly used organic solvents, and even in dichloromethane, 1,4-dioxane and tetrahydrofuran. The obtained polyimide films also exhibited excellent thermal stability with Tg between 270 °C and 311 °C, and decomposition temperatures at 10% weight loss (T10%) between 493 °C and 552 °C. Moreover, the 4,5-diazafluorene-containing polyimides showed low dielectric constant located between 2.78 and 3.38, good mechanical properties with tensile strength between 92 and 105 MPa and elongations at break in the range of 4.49–24.8%.
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
EUROPEAN POLYMER JOURNAL
·
2019
·
IF 3.621
Tongmou Geng,Guofeng Chen,Lanzhen Ma,Can Zhang,Weiyong Zhang,Heng Xu
Two new spirobifluorene-based conjugated microporous polymers, TS-TAD and TS-TADP, were constructed via Friedel-Crafts coupling reactions. TS-TAD and TS-TADP possess high BET surface area of 828 and 783 m 2 g −1 , large pore volume of 1.51 and 0.54 cm 3 g −1 , good stability, and display excellent guest uptake of 4.15 and 3.65 g g −1 in iodine vapour as well as reversible adsorption of iodine in solution. The specific surface areas of CMPs were increased by the introduction of bispirofluorene rings compared with the corresponding parent polymers. TS-TAD has a similar structure to TS-TADP, but possesses larger specific surface area and pore values than TS-TADP, hence, TS-TAD has a higher adsorption capacity for iodine than TS-TADP. Moreover, the adsorption rate of TS-TAD is slower than that of TS-TADP in I 2 vapor, while it is faster than that of TS-TADP in cyclohexane solution. We also highlight that the both resulting CMPs exhibit outstanding performance for fluorescent sensing to iodine and nitroaromatic compounds, thus making the resulting CMPs ideal absorbent materials for reversible iodine capture, sensing iodine and nitroaromatic compounds to address environmental issues.
研究领域:
材料科学
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环境科学
·
化学
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产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2016
·Vol. 24
·期 1
·363-371
·
IF 2.76
Jin Jingnan,Yao Jun,Liu Wenjuan,Zhang Qingye,Liu Jianli
In this study, a gram-positive fluoranthene-degrading bacterial strain was isolated from crude oil in Dagang Oilfield and identified as Microbacterium paraoxydans JPM1 by the analysis of 16S rDNA sequence. After 25 days of incubation, the strain JPM1 could degrade 91.78 % of the initial amount of fluoranthene. Moreover, four metabolites 9-fluorenone-1-carboxylic acid, 9-fluorenone, phthalic acid, and benzoic acid were detected in the culture solution. The gene sequence encoding the aromatic-ring-hydroxylating dioxygenase was amplified in the strain JPM1 by PCR. Based on the translated protein sequence, a homology modeling method was applied to build the crystal structure of dioxygenase. Subsequently, the interaction mechanism between fluoranthene and the active site of dioxygenase was simulated and analyzed by molecular docking. Consequently, a feasible degrading pathway of fluoranthene in the strain JPM1 was proposed based on the metabolites and the interaction analyses. Additionally, the thermodynamic analysis showed that the strain JPM1 had high tolerance for fluoranthene, and the influence of fluoranthene for the bacterial growth activity was negligible under 100 to 400 mg L −1 concentrations. Taken together, this study indicates that the strain JPM1 has high potential for further study in bioremediation of polycyclic aromatic hydrocarbon (PAH)-contaminated sites.
研究领域:
环境微生物学
·
生物化学
·
分子生物学
·
生物修复技术
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产品关联
DOI
PubMed
高影响因子
THERMOCHIMICA ACTA
·
2018
·
IF 2.189
Feng Bao,Lishuai Zong,Nan Li,Yuanyuan Song,Yunxing Pan,Jinyan Wang,Xigao Jian
In this study, a series of poly(phthalazinone fluorenyl ether ketone ketone) (PPFEKK) copolymers were designed and synthesized via nucleophilic aromatic substitution polymerization of 1,4-bis(4-fluorobenzoyl)benzene (BFBB), 4-(4-hydroxyphenyl)(2 H)-phthalazin-1-one (DHPZ) and 9,9-bis(4-hydroxyphenyl)fluorene (BHPF) to investigate the effects of bulky fluorene units on the processability and thermal degradation behavior of the polymers. The structures of the PPFEKKs were investigated and confirmed by FTIR, 1 H NMR, wide-angle X-ray diffraction (WAXD) and gel permeation chromatography (GPC) techniques. Traditional thermal measurements showed that the T d 5% and T d 10% values of the copolymers increased as the content of BHPF units increased from 0 to 100 mol%, while their glass transition temperatures gradually decreased. The rheological measurements showed that the processability of the copolymers significantly improved upon incorporation of BHPF units; the poly(aryl ether)s were less viscous and thus more processable. The thermal degradation kinetics were clarified using TGA with Kissinger’s method. The copolymer undergoes two thermal degradation processes: as the content of BHPF units in the copolymers increased from 0 to 100 mol%, the activation energy of the first degradation reaction increased from 228 to 254 kJ mol −1 , and the activation energy of the second degradation reaction increased from 271 to 298 kJ mol −1 . The resulting films displayed excellent tensile strength (higher than 76 MPa), and their Young’s modulus values were inversely proportional to their BHPF contents. Dynamic mechanical analysis showed storage modulus values at 30 °C of approximately 2662, 2826, 2698, 2791 and 2830 MPa for the prepared polymers. Furthermore, the PPFEKKs were soluble in a variety of organic solvents, making them suitable for film casting.
研究领域:
高分子化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2022
·
IF 10.753
Xiaoxuan Zhou,Tao Liu,Shengyi Zhang,Bo Kang,Xu Duan,Yuanyuan Yan,Leiyu Feng,Yinguang Chen
Fluorene (Flu) occurs widely in various environments and its toxicity to organisms is well-known. However, the impact of Flu on complicated biochemical processes involving functional microbial community has been reported rarely. In this study, the facilitation of Flu on the volatile fatty acids (VFAs) generation executed by acidogenic microbial population during sludge acidogenic fermentation (37 °C, SRT = 8 d, pH = 10.0) was investigated. The accumulation of VFAs (particularly acetic acid) increased initially and then declined with the increasing of Flu concentration (0‐500 mg/kg dry sludge), which reached a maximum (3211.1 mg COD/L) as Flu content was 200 mg/kg dry sludge . The Flu-enhanced VFAs production was primarily attributed to the shift of hydrolysis/acidification, as well as the corresponding functional microbial community and the activity of enzymes. Based on the metagenomics analysis, the conversion of organic substrates, i.e. amino acid and monosaccharide , into VFAs embraced in hydrolysis/acidification shaped by Flu was constructed at the genetic level. The relative abundances of genes included in aminotransfer and deamination process of amino acid and glycolysis of monosaccharide into VFA-precursors (pyruvate, acetyl-CoA and propionyl-CoA), and the further formation of VFAs were improved due to the Flu presence. This study shed light on the Flu-affected microbial processes at the molecular biology level during acidogenic fermentation and was of great significance in resource recovery of sludge containing persistent organic pollutants.
研究领域:
环境科学
·
分子生物学
·
微生物学
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产品关联
DOI
PubMed
高影响因子
POLYMER INTERNATIONAL
·
2021
·Vol. 70
·期 11
·1612-1620
·
IF 2.99
Kuan Liu,Yuhan Wei,Jinyao Xu,Lingfei Qiu,Shaping Hu,Jiayi Wan,Juhua Feng
A novel conjugated polymer PFCZ-IM containing 2-(thiophen-2-yl)-1H-benzo[d]imidazole units was synthesized and characterized. The basic photophysical properties of the polymer and its fluorescence recognition behaviors toward metal ions and amino acids were investigated. In the study of the response of metal ions, PFCZ-IM had high sensitivity to Fe 3+ , Ag + and Cu 2+ , which significantly quenched the fluorescence of the polymer. The binding of the 2-(thiophen-2-yl)-1H-benzo[d]imidazole moiety to Cu 2+ was investigated by density functional theory calculation. Interestingly, [PFCZ-IM-Cu 2+ ] also exhibited outstanding characteristics of fluorescence ‘turn on’ in the presence of cysteine (Cys), as the interaction between Cu 2+ and Cys caused the polymer to dissociate from the complex. In particular, addition of 30 μmol L –1 of Cys can increase the Cu 2+ -quenching fluorescence of PFCZ-IM by 34.8 times with short response time, demonstrating that [PFCZ-IM-Cu 2+ ] has tremendous potential in the actual detection of Cys. This polymer is expected to be utilized for dual fluorescence detection of specific metal ions and Cys. © 2021 Society of Industrial Chemistry.
研究领域:
材料科学
·
分析化学
·
生物化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）