APPLIED ORGANOMETALLIC CHEMISTRY
·
2021
·Vol. 35
·期 4
·e6147
·
IF 4.105
Sujuan Ge,Yuming Zhou,Xiaoli Sheng,Chunfeng Mao,Lina Zhao,Jianxing Xu,Lei Qiu
Piperidinium-based ionic liquids (ILs) were synthesized under mild conditions by coordinating N -alkyl- N -methylpiperidinium bromide ([Pip 1,x ]Br) with anhydrous AlCl 3 . The weak basicity of N -methylpiperidine had little impact on downstream problems from proton impurities and catalyst poisoning. The results of Fourier transform infrared (FT-IR), electrospray ionization mass spectrometry (ESI-MS), and nuclear magnetic resonance ( 27 Al NMR) confirmed that the active components in [Pip 1,x ]Br-2AlCl 3 ( χ = 0.67) were [Al 3 Cl 9 Br] − and [Al 2 Cl 6 Br] − . Besides, the reaction performance of [Pip 1,8 ]Br-2AlCl 3 under different conditions was carried out by single-factor experiment and further confirmed by orthogonal experimental method. Among these reaction conditions, the optimal combination was the reaction temperature of 40°C, ILs/O molar ratio of 0.2:1, px/O molar ratio of 12:1, and the reaction time of 30 min. Furthermore, [Pip 1,8 ]Br-2AlCl 3 had excellent stability and can be recycled 14 times. It was the high-efficiency catalytic activity and prominent recyclability that made continuous industrial production possible.
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Journal of Oleo Science
·
2017
·
IF 1.076
Gaoshang Wang,Shangde Sun
Estolides of ricinoleic acid (RA) have been used as lubricants and pigment dispersant in many industries. In this paper, functional acid ionic liquids (ILs) were firstly used as catalysts to prepare RA estolides by the esterification of RAs in solvent-free system. Different ILs were used as catalysts for the esterification. Effect of reaction variables (IL amount, reaction temperature and reaction time) on the esterification were also investigated and optimized using response surface methodology (RSM). Among all tested ILs, [BSO3HMIM]TS showed the best performance for the esterification. Arrhenius equation for the esterification was lnV0 =14.897-7558.7/T, and the activation energy (Ea) was 62.84 kJ/mol. A high degree of polymerization with an acid value of 48.0±2.5 mg KOH/g was achieved at the optimized conditions (IL load 12%, reaction temperature 140°C, and reaction time 12 h). The effect of reaction variables on the esterification decreased in the order of catalyst loading of IL > reaction temperature > reaction time.
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Energetic Materials Frontiers
·
2021
·
IF 0
Yang Liu,Yang Guo,Li-han Fei,Zhao-ming Mai,Cheng-long Tang,Zhi Wang,Ying-tao Wu,Zuo-hua Huang
Ionic liquids have a wide engineering application foresight due to their easy and safe storage and handling while are limited by the unclear mechanism of hypergolic ignition. In this study, three dicyanamide-based ionic liquids with different cations, 1-allyl-3-methyl imidazolium ([AMIm]), 1-ethyl-3-methylimidazolium ([EMIm]) and 1-butyl-3-methyl-imidazolium ([BMIm]), are prepared to react with white fuming nitric acid through drop tests. The diameter of ionic droplet is 2.2 mm, the impact velocities are controlled at 0.16/0.45/0.62/0.82/1.01 m s -1 by adjusting the dropping height, and the whole reacting process is recorded by three cameras to provide macroscopic, microscopic and infrared details. The promotion effect of impact velocity on hypergolic ignition probability is confirmed for all the ionic liquids, and the minimum impact velocity for successful hypergolic ignition of each ionic liquid was determined. The temperature evolution of hypergolic process shows a non-monotonic trend, and a four-stage process was performed to reveal the hypergolic mechanism. The experimental results indicate that short-chain alkyl and unsaturated substituents in cations are favored for hypergolic ignition, and the datasets are conducive for kinetic model construction.
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INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2019
·
IF 3.375
Long Liu,Sheng Gao,Zhiyi Jiang,Yanqiang Zhang,Dayong Gui,Suojiang Zhang
A series of amide-functionalized ionic liquids (ILs), e.g., 1-R-3-(2-amino-2-oxoethyl)-imidazolium (R = −vinyl, −methyl–butyl) cations combined with Cl–, N(CN)2–, or NTf2– anions, were synthesized and fully characterized as curing agent for diglycidyl-4,5-epoxy-cyclohexane-1,2-dicarboxylate (TDE-85). Studies of curing behaviors showed that ILs with N(CN)2– anions exhibit moderate curing conditions. As to thermosets of TDE-85 cured by these curing agents, their tensile strength (95.1–111.7 MPa) and elongation at break (2.69 to 4.20%) are significantly improved compared with the traditional curing systems of DDS/TDE-85 (DDS, 4,4′-diamino diphenyl sulphone). These thermosets also exhibit good thermal mechanical properties with the glass transition temperature (Tg) > 200 °C and thermal degradation temperature (Td) > 300 °C. The possible mechanisms of curing reactions were analyzed by using IR, and results indicated that curing reactions of TDE-85 with amide-functionalized ionic liquids may include three steps, −NH2 groups reacted with oxirane at lower temperatures, and then the anions further participated in the reaction to strengthen the cross-linking networks. This study provides informative guidelines for designing new curing agents.
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JOURNAL OF MOLECULAR LIQUIDS
·
2020
·
IF 5.065
Mengyi Qin,Fei Zhong,Yu Sun,Xiaoyan Tan,Kehui Hu,Huiwen Zhang,Mengke Kong,Guowei Wang,Linghua Zhuang
Anionic surface active ionic liquid (SAIL), 1-butyl-3-ethoxycarbonylimidazolium dodecanesulfate ([Etbim][C 12 H 25 SO 4 ]) was synthesized. The dependence of micellization of dodecanesulfate-based anionic SAILs on cation substituents of anionic SAILs was analyzed using experimental and theoretical studies. Critical micelle concentration of [Etbim][C 12 H 25 SO 4 ] was 1.17 mmol/L at 298.15 K. [Etbim][C 12 H 25 SO 4 ] showed superior surface property than [Bmim][C 12 H 25 SO 4 ] with same dodecanesulfate anion. Theoretical density functional theory (DFT) calculation was used to determine the micellization tendency of anionic SAILs ([Bmim][C 12 H 25 SO 4 ] and [Etbim][C 12 H 25 SO 4 ]). CMC difference of [Etbim][C 12 H 25 SO 4 ] and [Bmim][C 12 H 25 SO 4 ] was ascribed to the electrostatic interaction (repulsion or attraction) and hydrophobic interaction of cations ([Bmim] + and [Etbim] + ), dodecanesulfate anion, anionic SAILs ([Bmim][C 12 H 25 SO 4 ] or [Etbim][C 12 H 25 SO 4 ]), and the interactions toward water molecules in aqueous solution. The hydrocarbon chain lengths of [Bmim] + and [Etbim] + reflected the different hydrophobic interaction of cations, which clarified that the important role of cation substituents on micellization of [Etbim][C 12 H 25 SO 4 ] and [Bmim][C 12 H 25 SO 4 ]. Atomic charge distribution of cations will play important role on the further hydration toward water molecules or electrostatic attraction toward [C 12 H 25 SO 4 ] − anion. Typical hydrogen bonds and charge changes of typical atoms were beneficial for electrostatic attraction and electrostatic repulsion between polar groups of SAILs. The electrostatic repulsion and electrostatic attraction between polar groups of SAILs affected the CMC values of [Bmim][C 12 H 25 SO 4 ] and [Etbim][C 12 H 25 SO 4 ]. Changes of binding energy (D 0 ) and difference of binding energy (ΔD 0 ) confirmed the tendency of [Etbim][C 12 H 25 SO 4 ] micelle formation was higher than that of [Bmim][C 12 H 25 SO 4 ].
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JOURNAL OF PHARMACEUTICAL AND BIOMEDICAL ANALYSIS
·
2018
·
IF 2.831
Yanjie Zhang,Yingxiang Du,Tao Yu,Zijie Feng,Jiaquan Chen
In this paper, two spiral structure CILs, 1-butyl-3-methylimidazolium(T-4)-bis[(2S)-2-(hydroxy-κO)-3-methyl-butanoato-κO]borate(BMIm + BLHvB − ) and 1-butyl-3-methylimidazolium (T-4)-bis[(αS)-α-(hydroxy-κO)-4-methyl-benzeneacetato-κO]borate (BMIm + BSMB-)were applied to evaluate their potential synergistic effect with dextrin for CE enantiomeric separation. The established dextrin-based synergistic system with CILs as additives showed good separation performance towards four tested drugs, including duloxetine, ketoconazole, sulconazole and citalopram. It was also observed that significantly improved separation and selectivity for tested analytes were achieved in CILs/dextrin synergistic system compared to single dextrin system. Primary parameters, such as the concentration of CIL, dextrin concentration, buffer pH and applied voltage, were systematically investigated to optimize the enantiomeric separation with BMIm + BLHvB − /dextrin as model system. Finally, the method of Statistical Product and Service Solutions (SPSS) was exploited to further elucidate the influence of experimental parameters on the synergistic effect.
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JOURNAL OF CHROMATOGRAPHY A
·
2013
·
IF 4.612
Changzeng Wu,Jianji Wang,Zhiyong Li,Jun Jing,Huiyong Wang
In this work, glycine ionic liquids tetramethylammonium glycine ([N 1111 ][Gly]), tetraethylammonium glycine ([N 2222 ][Gly]), tetra-n-butylammonium glycine ([N 4444 ][Gly]), tetra-n-butylphosphonium glycine ([P 4444 ][Gly]) and tetra-n-pentylammonium glycine ([N 5555 ][Gly]) were synthesized and used to prepare aqueous two-phase systems (ATPSs) in the presence of K 2 HPO 4 . Binodal curves of such ATPSs and partition coefficients of a series of dinitrophenylated (DNP) amino acids in these ATPSs were determined at 298.15 K to understand the effect of cationic structure of the ionic liquids on the phase-forming ability of glycine ionic liquids, relative hydrophobicity between the phases in the ionic liquids ATPSs, and polarity of the ionic liquids-rich phases. With the attempt to correlate the relative hydrophobicity of the phases in the ATPSs with their extraction capability for proteins, partition coefficients of cytochrome-c in the ATPSs were also determined. It was shown that partition coefficients of cytochrome-c were in the range from 2.83 to 20.7 under the studied pH conditions. Then, hydrophobic interactions between cytochrome-c and the ionic liquid are suggested to be the main driving force for the preferential partition of cytochrome-c in the glycine ionic liquid-rich phases of the ATPSs. Result derived from polarity of the ionic liquids-rich phases supports this mechanism.
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ANALYTICAL SCIENCES
·
2022
·Vol. 38
·期 10
·1277-1287
·
IF 1.967
Liu Cuicui,Zhao Buyi,Liu Xiaobing,Zhang Ailin
A novel capillary electrochromatography method has been developed for the simultaneous quantification of ten benzimidazole fungicides in fruits. Herein, covalent organic frameworks (COFs) and ionic liquids (ILs) were successfully introduced to prepare open-tubular capillary column to improve the loading capacity and separation performance. The parameters effecting the analytical performance including pH and concentration of running buffer, separation voltage and the addition of organic solvent were investigated systematically. Under the optimized conditions, the method allowed the baseline separation of ten benzimidazole fungicides, and showed a good linearity in the range of 3.5–200 μg kg −1 with the detection limits between 1.0 and 2.8 μg kg −1 . The intraday and interday precisions for recoveries were lower than 7.9% and 12.2%, respectively. Intraday and interday precisions for their retention times were lower than 3.2% and 6.6%, respectively. Satisfactory recoveries for grape, pear and orange samples at two concentrations were obtained ranging from 85.0 to 95.9% with RSDs lower than 7.8%, demonstrating the potential applications of the open-tubular capillary electrochromatography method for trace benzimidazole fungicides analysis in fruits. Graphical abstract
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Green Chemical Engineering
·
2022
·
IF 0
Lingling Peng,Mingzhen Shi,Xiaomin Zhang,Wenjie Xiong,Xingbang Hu,Zhuoheng Tu,Youting Wu
Selective separation of CO 2 and H 2 S from CH 4 is of importance to the natural gas upgrading because of its corrosivity. As is well known, amine group can recognize reversibly CO 2 and H 2 S with a moderate interaction. With this in mind, this work prepared a series of amine-functionalized supported-protic-ionic-liquid membranes (SPILMs) for the selective separation of CO 2 and H 2 S from CH 4 . For comparison, aprotic ionic liquid membrane was also prepared for natural gas sweetening. The effect of temperature and transmembrane pressure difference on the permeability of single gas and ideal selectivity of CO 2 /CH 4 and H 2 S/CO 2 were studied. Facilitated transport mechanism was studied by NMR spectra. The permeability of CO 2 in primary amine functionalized [DMPDAH][Tf 2 N]-based membrane decreases with the increasing transmembrane pressure, indicating a typical feature of facilitated transport membrane. The permeability of CO 2 and the ideal selective of CO 2 /CH 4 are as high as 2000 barrers and 53.2 at 313.2 K in [DMPDAH][Tf 2 N] membrane, significantly higher than those in conventional ILs membrane. It is anticipated that these amine-functionalized SPILMs can provide alternative insight for the selective separation of CO 2 and H 2 S from CH 4 .
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RSC Advances
·
2015
·Vol. 5
·期 63
·50747-50755
·
IF 3.84
Bin Jiang,Xiaowei Tantai,Luhong Zhang,Li Hao,Yongli Sun,Lin Deng,Zhiqiang Shi
Polylactic acid (PLA) is a representative biodegradable polymer, which is expected to be a promising replacement for some petroleum-based materials. Noticeably, the properties of PLA products depend strongly on the quality of the lactide monomer, a crucial precursor of PLA production. In this work, a large range of different chlorostannate(II) ionic liquids (ILs), prepared by mixing 1-butyl-3-methyl-imidazolium chloride and tin(II) chloride in various molar ratios, xSnCl2, were firstly applied for the preparation of L-lactide of high chemical and optical purity. The cation–anion interaction, the thermal stability and the acidity of imidazolium-based chlorostannate(II) ionic liquids were experimentally determined and systematically analyzed. Compared with the conventional SnCl2 catalyst, the depolymerization of oligomeric poly(L-lactic acid) catalyzed by chlorostannate(II) ionic liquids occurred in a moderate yield. Interestingly, using [Bmim]Cl–SnCl2 (xSnCl2 = 0.63) as a catalyst, L-lactide of 99.9% optical purity was obtained, simultaneously leaving a high-Mw oligomeric residue with high isotacticity (99.1%). Furthermore, the effects of various reaction parameters were investigated in order to obtain the highest possible yield of lactide. A plausible reaction mechanism was suggested and discussed. Finally, owing to the reutilization of PLLA residue of high isotacticity, a reiterative lactide synthesis was realized. The recycled catalyst showed no notable loss of activity. By combining this chlorostannate(II)-based IL (xSnCl2 = 0.63) catalyst technology with the cyclic resynthesis process, high-quality L-lactide could be selectively produced in high yield (>80%, based on L-lactic acid replenished).
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高影响因子
APPLIED SURFACE SCIENCE
·
2017
·
IF 3.387
Dan Liu,Gang Li,Haiou Liu
A kind of multi-functional sites metal-organic framework (MOF) composite (MIL-101-IMBr) was successfully prepared by post-synthesis modification of MIL-101 with imidazolium-based ionic liquids. The ionic liquids not only functionalize as basic sites but also provide halide anions, which serve as a nucleophile in cycloaddition reaction. The prepared functional MOF materials were characterized by X-ray diffraction, fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive spectroscopy, N 2 adsorption-desorption and CO 2 temperature programmed desorption. The results of fourier transform infrared spectroscopy and energy dispersive spectroscopy show that the MIL-101-IMBr composite was successfully synthesized. The N 2 adsorption-desorption results clearly demonstrated that the modified composites still preserve high BET surface area and total pore volume. The composite exhibits high catalytic activity for the cycloaddition of CO 2 with epoxides under mild and co-catalyst free conditions. The conversion of propylene oxide was 95.8% and the selectivity of cyclic carbonate was 97.6% under 0.8 MPa at 80 °C for 4 h. Moreover, the catalyst can be used for at least five times.
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Applied Sciences-Basel
·
2018
·Vol. 8
·期 5
·770
·
IF 1.689
Peng Lu,Yong Cao,Xiaolan Wang
Macroporous cardo polyetherketone (PEK-C) powder catalyst bearing covalently ionic liquids (PEK-C-ILs) was prepared, it exhibited a high catalytic performance for biomass hydrolysis. A hydrolysis mechanism of inulin over this new catalyst was proposed as well. The influences of degree of chloromethylation of PEK-C, catalyst dosage, reaction temperature, pore size of PEK-C-ILs and inulin concentration were investigated. A high conversion of inulin of 99.7% was obtained under the optimal reaction conditions. Meanwhile, the hydrolysis kinetics was studied under different conditions. The proposed kinetic model of inulin hydrolysis catalyzed by PEK-C-ILs was established and it successfully predicted the inulin hydrolysis in wider ranges of experimental conditions. The results demonstrated that the catalytic inulin hydrolysis performance of PEK-C-ILs is better than that of homogenous ILs due to that there was a high-density spatial distribution of active sites on the surface and inner pore wall of PEK-C after the ILs was immobilized. Furthermore, the stability including chemical structure and physical appearance and reusability tests showed that PEK-C-ILs catalyst could be effectively separated and recovered from hydrolysates and has excellent reusability. Importantly, using the PEK-C-ILs as catalyst makes the recycling of ILs simplified, efficient and the hydrolysis process more economical. At the same time, it avoided the potential hazards of homogenous ILs to the environment. Therefore, it is a kind of green catalyst with potential application prospect in many catalysis fields.Keywords:cardo polyetherketone;ionic liquids;immobilization;macroporous powder catalyst;inulin hydrolysis
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危险品化学品经营许可证（带存储）