FLUID PHASE EQUILIBRIA
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2017
·
IF 2.473
Xu Zhao,Haihong Wu,Mengshan Duan,Xiaocui Hao,Qiwei Yang,Qi Zhang,Xiping Huang
Ionic liquids (ILs) have been proposed as promising extractants to broaden the potential utility of liquid–liquid extraction process for lithium, but developing an attractive IL from numerous available ILs remains challenging. In this work, a rapid preliminary predicting and screening method based on COSMO-RS was proposed. The design strategy was to collocate anions that had intensive affinity to lithium ion with high hydrophobic cations. Based on it, a series of candidate ILs were prepared and characterized by 1 H and 13 C NMR spectroscopy, including [P 4444 ]-based and [N 4444 ]-based ILs with phosphate, phosphinate and long-chain carboxylate anions. The further extraction experiments indicated that the tetrabutylammonium mono-2-ethylhexyl(2-ethylhexyl)phosphate ([N 4444 ][EHPMEH]) had the highest Li + extraction efficiency. The extraction mechanism was investigated by slope analysis method and ATR-IR spectroscopy. It was determined that every Li + associated with 1.33 molecule [N 4444 ][EHPMEH] to form the extracted species. The stripping study showed that the Li + was able to be stripped by only 0.5 mol/L HCl without additional agents. The extraction experiments of Li + from multi-metal-ion solution were also carried out, and the distribution ratio of Li + was nearly twice those of Na + , K + , and Rb + , indicating that [N 4444 ][EHPMEH] was available to separate lithium ion from the other alkali metal ions.
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EUROPEAN POLYMER JOURNAL
·
2024
·
IF 5.8
Fei Xiao,Wenlong Shao,Xuefei Gao,Yue Shi,Yanyan Liu,Bihe Yuan,Kaiyuan Li
The emergence of ionic liquids provides an effective way to construct new advanced multifunctional epoxy resin (EP) composites with excellent fire retardancy and mechanical properties. In this study, 1-butyl-3-methylimidazolium dibutyl phosphate (BDBP) was synthesized via a facile strategy and then incorporated into the EP matrix. The results showed that ultra-low loading of BDBP (1 wt%) enabled EP composite to achieve a V-0 rating (3.2 mm) in the UL-94 test. When increasing the loading to 4 wt%, the limiting oxygen index (LOI) of EP/BDBP4 composites was improved to 31.9 %. Meanwhile, the peak heat release rate (PHRR), total heat release (THR), and total smoke production (TSP) significantly decreased by 48.1 %, 21.9 %, and 13.5 %, respectively, compared to neat EP. Moreover, the presence of BDBP increased the tensile strength of EP/BDBP2 by more than 7 %, while all EP/BDBP composites maintained high transparency. In summary, this work provides a feasible and low-cost idea for constructing multifunctional EP composites, paving the way for their applications in aerospace, wind turbines, and electronic and electrical fields.
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CHINESE JOURNAL OF CATALYSIS
·
2012
·
IF 1.171
Yanhong BI,Zhaoyu WANG,Yanyong MAO,Shangyong ZHENG,Haijiang ZHANG,Hao SHI
The preparation of salidroside was successfully carried out in fourteen ionic liquids (ILs)-containing systems using β-glycosidase from black plum seeds for the first time. The optimum conditions were determined for C 6 MIm·BF 4 , pH, phosphate buffer content, and molar ratio of tyrosol to D-glucose to be 1% (v/v), 5.9, 20% (v/v), and 8:1, under which the initial reaction rate and yield were 3.3 mmol/(L·h) and 24.5%, respectively. Moreover, the effects of 1-alkylimidazolium-based ILs possessing different alkyl chain lengths from C 2 to C 10 and a variety of anions including BF 4 − , PF 6 − , Cl − , Br − , and I − on enzyme activity in co-solvent systems were investigated. The results indicate that the optimal chain length of the alkyl substituent on the imidazolium ring of the cation was C 6 . 摘要 研究了混合溶剂体系中阴离子分别为 BF 4 − , PF 6 − , Cl − , Br − 和 I − 的 14 种离子液体对来源于黑布林糖苷酶催化合成红景天苷反应的影响. 结果表明, 在最佳反应条件下, β-糖苷酶的反应初速度和红景天苷的产率分别为 3.3 mmol/(L·h) 和 24.5%. 离子液体咪唑阳离子的烷基链长 (C 2 ∼C 10 ) 对 β-糖苷酶的活性影响较大, 当烷基链长为 C 6 时, 糖苷酶表现出较高的催化活性.
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BIOELECTROCHEMISTRY
·
2011
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IF 3.52
Jun-Yong Sun,Ke-Jing Huang,Su-Fang Zhao,Yang Fan,Zhi-Wei Wu
TiO 2 -graphene nanocomposite was prepared by hydrolysis of titanium isopropoxide in colloidal suspension of graphene oxide and in situ hydrothermal treatment . The direct electrochemistry and electrocatalysis of hemoglobin in room temperature ionic liquid 1-Butyl-3-methylimidazolium hexafluorophosphate, chitosan and TiO 2 -graphene nanocomposite modified glassy carbon electrode were investigated. The biosensor was examined by using UV-vis spectroscopy, scanning electron microscopy and electrochemical methods. The results indicated that hemoglobin remained its bioactivity on the modified electrode , showing a couple of well-defined and quasi-reversible redox peaks, corresponding to hemoglobin Fe III /Fe II couple. The kinetic parameters for the electrode reaction , such as the formal potential ( E o' ), the electron transfer rate constant ( k s ), the apparent coverage ( Γ ), and Michaelis–Menten constant ( K m ) were evaluated. The biosensor showed good electrochemical responses to the reduction of H 2 O 2 in the ranges of 1–1170 μM. The detection limit was 0.3 μM (S/N = 3). The properties of this composite film, together with the bioelectrochemical catalytic activity , could make them useful in the development of bioelectronic devices, and investigation of electrochemistry of other heme proteins at functional interface.
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PubMed
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2010
·
IF 2.338
Tao Liu,Xiangbin Zhu,Lin Cui,Peng Ju,Xiangjin Qu,Shiyun Ai
A novel and reliable electrochemical sensor based on PbO 2 -carbon nanotubes-room temperature ionic liquid (i.e., 1-butyl-3-methylimidazolium hexafluorophosphate, BMIMPF6) composite film modified glassy carbon electrode (GCE) (PbO 2 –MWNT–RTIL/GCE) was proposed for simultaneous and individual determination of guanine and adenine . The guanine and adenine oxidation responses were monitored by differential pulse voltammetric (DPV) measurement. Compared with the bare electrode, the PbO 2 –MWNT–RTIL/GCE not only significantly enhanced the oxidation peak currents of guanine and adenine, but also lowered their oxidation overpotentials, suggesting that the synergistic effect of PbO 2 , MWNT and RTIL could dramatically improve the determining sensitivity of guanine and adenine. The PbO 2 –MWNT–RTIL/GCE showed good stability, high accumulation efficiency and enhanced electrocatalytic ability for the detection of guanine and adenine. Besides, the modified electrode also exhibited good behaviors in the simultaneous detection of adenine and guanine with the peak separation of 0.29 V in 0.1 M pH 7.0 phosphate buffer solution (PBS). Under the optimal conditions, the detection limit for individual determination of guanine and adenine was 6.0 × 10 −9 M and 3.0 × 10 −8 M ( S / N = 3), respectively. The proposed method for the measurements of guanine and adenine in herring sperm DNA was successfully applied with satisfactory results.
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RSC Advances
·
2015
·Vol. 5
·期 76
·62241-62247
·
IF 3.84
Yibo He,Chao Wan,Qinghua Zhang,Xiaoli Zhan,Dang-guo Cheng,Fengqiu Chen
Friedel–Crafts alkylation of benzene with 1-dodecene, which is an important reaction of synthetic detergent, was studied using the catalyst [bmim][TFSI]/AlCl3 (1-butyl-3-methylimidazolium bis((trifluoromethyl)sulfonyl)imide/AlCl3). These ionic liquid catalysts show biphasic behaviors at a specific condition. Active site species and Lewis acidity were determined by NMR and acetonitrile probe FT-IR. NMR spectroscopy investigations indicated that “coordinated” and “uncoordinated” [TFSI]− existed in the ionic liquid catalyst system simultaneously, while tetrahedral 4-coordinate Al2Cl7− was the main active species for Friedel–Crafts alkylation. The complex [AlClx(TFSI)y]− tends to decompose and release 4-coordinated Al2Cl7− and [TFSI]−. The phase behavior study of the ionic liquid [bmim][TFSI]/AlCl3 demonstrated that the upper phase could be used as an efficient heterogeneous catalyst when AlCl3/IL ≥ 1.5. Due to the presence of the anion [TFSI]− around the active sites, especially [TFSI]− at the “uncoordinated” state, the ionic liquid formed a stable and hydrophobic chemical environment, which enhanced catalyst durability. The influence of various reaction conditions including catalyst reusability on the alkylation reaction was studied, and the potential reasons for catalyst deactivation were discussed. The highest 2-LAB selectivity was more than 50% when 1-dodecene conversion was nearly 100%. Compared with liquid or solid acid catalyst, ionic liquid catalysts have many advantages concerning energy and the environment.
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SEPARATION SCIENCE AND TECHNOLOGY
·
2016
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IF 1.083
Runping Wang,Yuena Chang,Zhijian Tan,Fenfang Li
Choline leucine ionic liquid solution was chosen to simultaneously extract flavonoids and pectin from ponkan peels, which were subsequently isolated by the corresponding K3PO4-based aqueous biphasic systems (ABS). Under optimized conditions of 54% solution for 100 min extraction at liquid–solid ratio 17, the predicted yields of flavonoids and pectin achieved 1.33% and 13.42%, respectively, the flavonoids determined directly after extraction and the pectin after ABS purification, with the two corresponding measured yields of 1.26% ± 0.04% and 12.85% ± 0.51%. Under optimal extraction, crude flavonoids contained maximal total flavonoid content of about 20% ± 1% after purification of the ABS involving 25% K3PO4 and dilution precipitation. What was directly isolated from K3PO4-rich phase was presumed to be a modified pectin.
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JOURNAL OF SOLID STATE ELECTROCHEMISTRY
·
2016
·Vol. 20
·期 6
·1783-1792
·
IF 2.327
Yan Huiqiong,Chen Xiuqiong,Shi Zaifeng,Feng Yuhong,Li Jiacheng,Lin Qiang,Wang Xianghui,Sun Wei
In this work, electrodeposition of the mixture of myoglobin (Mb), sodium alginate (SA), and TiO 2 nanoparticles on the carbon ionic liquid electrode (CILE) was performed to fabricate the modified electrode which was abbreviated as Nafion/Mb-SA-TiO 2 /CILE. FT-IR and UV-vis absorption spectra confirmed that Mb could retain its native structure after being immobilized in the SA-TiO 2 composite film. The electrochemical characterization of Nafion/Mb-SA-TiO 2 /CILE revealed that a pair of symmetric redox peaks appeared in the cyclic voltammograms, indicating that direct electron transfer of Mb was realized on the modified electrode. The good biocompatibility of SA, the good electrocatalytic capability of TiO 2 nanoparticles, and their synergistic effects were beneficial to the electron transfer between Mb and CILE. The electrochemical parameters of the electron transfer number ( n ), the charge transfer coefficient ( α ), and the electron transfer rate constant ( k
s
) were calculated as 1.032, 0.402, and 0.511 s −1 , respectively. The modified electrode exhibited good electrocatalytic ability to the reduction of trichloroacetic acid (TCA) and displayed wide linear range from 5.3 to 114.2 mmol/L and low detection limit as 0.152 mmol/L (3 σ ). The apparent Michaelis-Menten constant K
M
app was 32.3 mmol/L. The proposed electrode with good stability and reproducibility had the potential application in the third-generation electrochemical biosensors.
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FUEL
·
2017
·
IF 4.601
Zhong-Qiu Liu,Xian-Yong Wei,Hai-Hong Wu,Wei-Tu Li,Yang-Yang Zhang,Zhi-Min Zong,Feng-Yun Ma,Jing-Mei Liu
Modified microfiber attapulgite (MFA)-supported nickel was prepared by thermally decomposing nickel tetracarbonyl on MFA modified with an acidic ionic liquid (AIL, 1-sulfobutyl-3-methylimidazolium trifluoromethanesulfonate). It was characterized with multiple instruments and used for catalyzing hydroconversion of lignite-related model compounds (LRMCs) oxydibenzene, benzyloxybenzene, and oxybis(methylene)dibenzene. The results indicate that Ni 15% /MFA@AIL effectively catalyzes hydroconversion of the LRMCs to afford cyclanes by inducing the formation of H + , H − , and biatomic active hydrogen.
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RSC Advances
·
2017
·Vol. 7
·期 4
·2315-2322
·
IF 3.108
Jianbo Li,Yanhui Wang,Yuanling Sun,Chaofan Ding,Yanna Lin,Weiyan Sun,Chuannan Luo
A simple and sensitive electrochemical sensor for detection of dopamine has been developed based on ionic liquid functionalized graphene oxide supported gold nanoparticles (GO-IL-AuNPs) coated onto a glassy carbon electrode. The prepared graphene oxide, ionic liquid functionalized graphene oxide and GO-IL-AuNPs were characterized in detail by scanning electron microscopy, X-ray diffraction and Fourier transform infrared spectroscopy. The electrochemical properties of the hybrid nanomaterials were evaluated through cyclic voltammetry and electrochemical impedance spectroscopy. Meanwhile, the activities of hybrid nanomaterials toward the oxidation of dopamine were analyzed via cyclic voltammetry and differential pulse voltammetry. The resulting sensor showed excellent electrocatalytic activity towards dopamine. Under the optimum conditions, differential pulse voltammetry was employed to detect ultra-trace amounts of dopamine, for which a wide linear range of 7 nM to 5 μM and a limit of detection 2.3 nM (S/N = 3) were obtained. The proposed sensor exhibited excellent accuracy and precision and the relative standard deviation (RSD) was less than 5%. The highly sensitive sensor was successfully used for accurate determination of the content of dopamine in practical samples.
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Food Additives and Contaminants Part A-Chemistry Analysis Control Exposure & Risk Assessment
·
2016
·
IF 1.878
Xiaojun Wang,Long Wu,Jiaqi Cao,Xincheng Hong,Rui Ye,Weiji Chen,Ting Yuan
A novel, simple and rapid method based on magnetic effervescent tablet-assisted ionic liquid dispersive liquid–liquid microextraction (MEA-IL-DLLME) followed by graphite furnace atomic absorption spectrometry (GFAAS) determination was established for the speciation of selenium in various food and beverage samples. In the procedure, a special magnetic effervescent tablet containing CO2 sources (sodium carbonate and sodium dihydrogenphosphate), ionic liquids and Fe3O4 magnetic nanoparticles (MNPs) was used to combine extractant dispersion and magnetic recovery procedures into a single step. The parameters influencing the microextraction efficiency, such as pH of the sample solution, volume of ionic liquid, amount of MNPs, concentration of the chelating agent, salt effect and matrix effect were investigated and optimised. Under the optimised conditions, the limits of detection (LODs) for Se(IV) were 0.021 μg l–1 and the linear dynamic range was 0.05–5.0 μg l–1. The relative standard deviation for seven replicate measurements of 1.0 μg l–1 of Se(IV) was 2.9%. The accuracy of the developed method was evaluated by analysis of the standard reference materials (GBW10016 tea, GBW10017 milk powder, GBW10043 Liaoning rice, GBW10046 Henan wheat, GBW10048 celery). The proposed method was successfully applied to food and beverage samples including black tea, milk powder, mushroom, soybean, bamboo shoots, energy drink, bottled water, carbonated drink and mineral water for the speciation of Se(IV) and Se(VI) with satisfactory relative recoveries (92.0–108.1%).
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PubMed
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CHINESE JOURNAL OF CHEMISTRY
·
2017
·Vol. 35
·期 11
·1739-1748
·
IF 1.852
Wenwen Yuan,Yi Huang,Chunyan Wu,Xiang Liu,Yongmei Xia,Haijun Wang
The development of novel methods to obtain biofuels and chemicals from biomass has been an immediate issue in both academic and industrial communities. In this work, a series of novel catalysts were prepared and characterized by FT-IR, TGA, XRD, SEM, TEM, ICP-AES, NH 3 -TPD and BET, which were applied for the conversion of hexose to 5-hydroxymethylfurfural (HMF). The Cr(Salten)-MCM-41-[(CH 2 ) 3 SO 3 HVIm]HSO 4 catalyst was the most active catalyst, and a glucose conversion of 99.8% with 50.2% HMF yield was obtained at 140 °C for 4 h in dimethyl sulfoxide (DMSO). The effects of reaction temperature, reaction time, solvents and catalyst dosages were investigated in detail. MCM-41 immobilized acidic functional ionic liquid and chromium(III) Schiff base complexes as heterogeneous catalysts can be easily recovered by simple filter treatment, exhibiting excellent stability and activity towards hexose conversion. Thus the heterogeneous catalysts were environment-friendly for transforming biomass carbohydrates into fine chemicals.
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危险品化学品经营许可证（带存储）