SENSORS AND ACTUATORS B-CHEMICAL
·
2016
·
IF 4.758
Yunsheng Dong,Tianqi Liu,Xuejuan Wan,Hang Pei,Lisi Wu,Youwei Yao
A bipyridine-based colorimetric/fluorometric chemosensor (LBD) was designed and prepared via a facile one-step synthesis with high yield, and the obtained chemosensor exhibited a specific detection performance toward Al 3+ in DMSO/H 2 O solution (7:3, v/v, 10 mM HEPES, pH 7.4) with relative low interference of other common metal cations. As a colorimetric sensor, the absorbance peak centered at 315 nm and 400 nm enhanced after the addition of Al 3+ , while the absorbance peak centered at 275 nm and 344 nm gradually decreased. Distinctive colorimetric transition of LBD from colorless to light yellow was also clearly discerned. Simultaneously, a significant turn-on fluorescence response of LBD at 495 nm and an apparent fluorescence emission variation from non-fluorescent to strong bright cyan was also observed by naked eye, which can be ascribed to the inhibited C = N isomerization and photo-induced electron transfer (PET) in LBD after the addition of Al 3+ . A stoichiometric complexation of 1:1 molar ratio between LBD and Al 3+ was confirmed and the detection limit of LBD was found to be 9 nM.
研究领域:
分析化学
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材料科学
✓ 已验证
DOI
高影响因子
Molecular Catalysis
·
2025
·
IF 4.9
Qingtao Niu,Maifen Yang,Xingan Wang,Aihua He,Manman Jin
Immobilization of active site on solid support plays great roles in improving catalyst performance. In this study, a series of solid supported iron precatalysts via the immobilization of iron halides (FeX n , X = Cl, Br or I, n = 2 or 3) on the metal-organic frameworks of UiO type bearing bipyridine moiety (bpy-UiO) were synthesized and used for isoprene polymerization. These bpy-UiO supported iron precatalysts (bpy-UiO-FeX n ) were also well characterized by the powder X-ray diffraction, elemental analysis and N 2 adsorption measurement. Upon activation with trialkylaluminums (AlEt 3 , Al(i-Bu) 3 and AlOct 3 ), bpy-UiO-FeX n exhibited excellent catalytic activity for isoprene polymerization. Interestingly, the iron(III) precatalysts had higher activity than the iron(II) precatalysts, and the highest activity was 1726.4 Kg⋅P/(mol⋅Fe⋅h) for bpy-UiO-FeBr 3 with AlEt 3 . Moreover, the activity gradually increased as the polymerization temperature increased from 0 °C to 50 °C, reflecting the fact that the MOFs supported iron catalysts had excellent thermal stability. Notably, the obtained polyisoprene had the ultrahigh molecular weight ( M w = 1.20×10 6 –3.13×10 6 Daltons), and predominantly consisted of 38.5–54.4 mol % cis -1,4 configuration and 45.6–61.5 mol % 3,4-configuration. This work offers an opportunity to design the high active and stable iron catalyst for conjugated diene polymerization based on the solid support.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
Polymer Chemistry
·
2020
·Vol. 11
·期 31
·5057-5066
·
IF 5.342
Jianrui Zhang,Xiaocui Han,Cheng Yue,Di Liu,Ziyu Lin,Yirong Sun,Liyuan Chen,Jinhui Pang,Zhenhua Jiang
A new diamine monomer with a dioxinyl bipyrimidine group was synthesized. Polyimide containing a bipyrimidine group was successfully homopolymerized by chemical imidization. Analyses to determine the structure and properties of these polymers were conducted using 1H NMR and FTIR spectroscopy and gel permeation chromatography (GPC). For the first time, cobalt acetate was incorporated into the synthesized polyimide to fabricate cobalt-complexed polyimide thin film composite membranes (TFCMs) by spin coating. To fully understand the behavior of cobalt complexed TFCMs, these membranes were synthesized and then characterized by FTIR spectroscopy, X-ray diffraction (XRD), and differential scanning calorimetry (DSC) to survey the effects of cobalt acetate on polyimide. The morphologies of TFCMs were determined using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). Phase separations and defects were absent in all cobalt-complexed TFCMs; the average thickness of the films ranged from 550 to 600 nm. This strongly suggested that cobalt acetate has good compatibility with bipyrimidine polyimide. The gas separation performance for TFCMs was also determined with the following results: the CO2 permeance of DMD-PI-3.0 (mixing 3.0 wt% cobalt acetate) TFCMs was 69.9 GPU at 35 °C and 1.5 bar while the selectivity of CO2/CH4 was 44.79 for DMD-PI-15 TFCMs. In short, this work reports a promising method to utilize the separation characteristics of polyimide TFCMs by incorporating cobalt ions.
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
JOURNAL OF MOLECULAR LIQUIDS
·
2021
·
IF 6.165
Juantao Zhang,Minjian Kong,Jiangtao Feng,Chengxian Yin,Danping Li,Lei Fan,Qibin Chen,Honglai Liu
A new type of the dimeric imidazolium-type amphiphile, BDBC m IB (m = 1, 4 and 8), was synthesized using the bipyridiyl as the spacer, and its inhibition performance and mechanism for the corrosion of N80 carbon steel in 1.0 mol·L −1 HCl were evaluated using chemical and electrochemical measurements, surface analyses and density functional theory (DFT) calculations. Results show that the inhibition efficiency of BDBC m IBs increases with their concentrations and the length of tail chains. BDBC 8 IB exhibits the best inhibition performance among them and its inhibition efficiency almost exceeds 90% in a wide concentration range from 1.0 × 10 −6 to 5.0 × 10 −4 mol·L −1 mol·L −1 at 25.0 °C, which attains the maximum over 95% at 5.0 × 10 −4 mol·L −1 . Moreover, three BDBC m IBs all display the high inhibition efficiency at 5.0 × 10 −4 mol·L −1 , nearly exceeding 90%, in the temperature range from 25.0 to 55.0 °C. As a mixed-type inhibitor, BDBC m IBs can retard both cathodic hydrogen evolution and anodic metal dissolution processes, since BDBC m IB molecules bear the imidazolium-based heterocycle with the electron-donating ability and the bipyridine with the electron-accepting ability, thereby facilitating the formation of a protective film on the surface of N80 carbon steel via electrostatic interactions, coordinated and back-donating bonds. The adsorption of BDBC m IBs obeys the Langmuir isothermal model. Our finding demonstrates that the introduction of the bipyridiyl at the spacer does favor improving the inhibition efficiency of such dimeric imidazolium-type amphiphiles, and meanwhile, the proper increase in the number of carbon atoms in the substituents on the imidazole rings can also enhance the inhibition efficiency.
研究领域:
材料科学
·
电化学
·
理论化学
✓ 已验证
DOI
高影响因子
ChemCatChem
·
2021
·Vol. 13
·期 17
·3772-3780
·
IF 5.686
An Li,Xinyang Wang,Yuhang Li,Caiwu Luo,Jiance Zhang,Kun Liu,Cen Zhang,Congshan Zhou
Graphical Quinoline synthesis : A novel gemini sulfonic acidic pyridiniumium ionic liquid immobilized MCM-41 was successfully prepared as a green heterogeneous catalyst, which exhibited high catalytic activity and excellent reusability in quinoline synthesis. A novel 2,2′-bipyridine-based gemini sulfonic ionic liquid was first synthesized and then immobilized on MCM-41 support (named IL1/MCM-41), which was further characterized using XRD, FT-IR, SEM, TEM, N 2 -physisorption, XPS and TG techniques. These characterization results revealed that the IL1/MCM-41 presented a whole ordered mesoporous structure, excellent thermal stability as well as the interaction between ionic liquid with MCM-41. Catalytic activity of the obtained IL1/MCM-41 was systematically evaluated for the Doebner-Von Miller reaction to generate quinoline. Compared to conventional imidazole-type single sulfonic ionic liquid supported on MCM-41 (named IL2/MCM-41), IL1/MCM-41 exhibited higher catalytic activity and better reusability, which was probably due to the synergistic catalytic effect of the dual sulfonic acid group on IL2 and the stronger interaction between dipyridine ring of ionic liquid with MCM-41 support, respectively. Meanwhile, a plausible reaction routes for the synergistic catalytic action of dual sulfonic acid to quinoline over the IL1/MCM-41 catalyst was also proposed in this paper.
研究领域:
化学工程
·
材料科学
✓ 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）