GREEN CHEMISTRY
·
2020
·Vol. 23
·期 1
·405-411
·
IF 9.48
Huiyong Wang,Jingjing Cui,Yuling Zhao,Zhiyong Li,Jianji Wang
Ionic liquids (ILs) have been widely studied as effective reaction media or catalysts for the conversion of renewable resources to 5-hydroxymethhylfurfural (5-HMF). However, the separation of 5-HMF from ILs remains a significant challenge. Thus, the aim of this work is to develop a useful guideline for the selection and design of greener solvents for efficient separation of 5-HMF from ILs by a simple solvent extraction approach. To this end, 9 kinds of low-toxic and medium boiling point organic solvents and 10 kinds of ILs typically used in biomass conversion have been evaluated for the separation of 5-HMF. The effects of the solvent hydrogen bond acceptor capacity, anion type and cationic structure of the ILs on the separation of 5-HMF from the ILs are systematically investigated and the molecular interactions among 5-HMF, ILs and the solvent contained in the mixtures have been revealed by FTIR and 1H NMR measurements. It has been found that besides a low mutual solubility with ionic liquids, an ideal solvent should have strong hydrogen bond acceptor properties. At the same time, the interactions between the anion and cation of the ILs and the hydrogen bonding interaction of the anion with 5-HMF are also very important for the separation of 5-HMF. A weak interaction of the anion with 5-HMF and a strong interaction between the anion and cation of the ILs all result in the high extraction efficiency. Under the optimized conditions, the extraction efficiency of 5-HMF from the ILs is up to 61.0%, which is a record-breaking value at the current time. This finding provides a useful guide for the selection of greener solvents for the separation of 5-HMF from ILs.
✓ 已验证
产品关联
DOI
高影响因子
Molecular Catalysis
·
2020
·
IF 3.687
Qianqian Zhang,Xianbao Cui,Tianyang Feng,Ying Zhang,Xuemei Zhang,Jie He,Jixiao Wang
Acidic ionic liquids were employed to catalyze the hydrolysis of methyl acetate . The optimal ionic liquid catalyst 1-butylsulfonic-3-methylimidazolium trifluoromethanesulfonate ([BSO 3 HMIm][OTf]) was selected from four Brönsted acidic ionic liquids. The reaction kinetics and chemical equilibrium of hydrolysis reaction catalyzed by [BSO 3 HMIm][OTf] were investigated. The hydrolysis mechanism catalyzed by [BSO 3 HMIm][OTf] was proposed, and non-ideal pseudo-homogeneous (NIPH) model was derived based on the hydrolysis mechanism. The hydrolysis reaction with mixed ionic liquids as catalyst and solvent was also conducted. The influence of solvent 1-octyl-2,3-dimethylimidazolium bis((trifluoromethyl)sulfonyl)imide ([OMMIm][Tf 2 N]) on the reaction rate was investigated. The chemical-phase equilibrium (CPE) was measured to investigate the effects of [BSO 3 HMIm][OTf] and [OMMIm][Tf 2 N] on chemical equilibrium and vapor-liquid equilibrium of the reaction mixture. The results show that chemical equilibrium constant is not affected by IL catalyst and solvent, but the vapor-liquid equilibrium is significantly influenced by IL solvent.
✓ 已验证
产品关联
DOI
高影响因子
Applied Sciences-Basel
·
2020
·Vol. 10
·期 3
·894
·
IF 2.474
Jianhui Gu,Huimin Zang,Shun Yao,Xuejiao Wang,Minghui Zhu,Hang Song
Ionic liquids (ILs) are considered to be a new type of solvent due to their low vapor pressure, some unique properties and are expected to be used widely in the following days. Given their water solubility, stable chemical structure, and biological toxicity, ILs probably reach aquatic environments and become long-term pollutants. We studied the fate of benzothiazolium-based ionic liquids catalyzed by UV-H2O2in water. Due to the synergistic effect of UV and H2O2, the degradation efficiency can be significantly improved compared to any of them alone. Fitting results showed that the degradation reaction follows pseudo-first-order kinetics and reaction rate constants with hydroxyl radicals ranging from 0.0005 s−1to 0.0529 s−1. The experimental data showed that satisfactory results can be obtained at a temperature of 45 ℃, an initial concentration of ionic liquid of 0.1 M, and a hydrogen peroxide concentration of 0.1 M. We also explored the effects of chloride ions and pH on degradation reactions. In an appropriate situation, the degradation yield of [C4Bth]PF6could achieve 97% in 60 min and 99% in 90 min. The UV-H2O2combination process could provide an effective technique for the treatment of benzothiazolium-based ionic liquids in wastewater.Keywords:photocatalysis;degradation;benzothiazole ionic liquid;H2O2
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2020
·
IF 5.578
Hongyan Wang,Song Ma,Zhimao Zhou,Minjie Li,Hui Wang
The alkylation process of iso butane with butene is important in the petroleum industry. Ionic liquids (ILs) are considered as attractive alternative catalysts for iso butane alkylation besides strong liquid acids (H 2 SO 4 or HF) and solid superacids. In this study, ILs based on amides-aluminum chloride (AlCl 3 ) were synthesized and characterized, which exhibited both Lewis and Brønsted acidities. These deep eutectic ILs were found to be efficient catalysts for iso butane alkylation. The influences of the amide substrate, AlCl 3 /amide molar ratio, and metal additive on Lewis and Brønsted acidities were observed together with the synergetic effect of Lewis and Brønsted acid sites in the catalytic process. CuCl modified Urea-1.6AlCl 3 showed the best catalytic performance. The butene conversion was about 99.9% and C8 selectivity reached 57.6% under optimized reaction conditions (temperature of 15 °C, stirring rate of 1500 rpm, hydrocarbon feeding rate of 300 mL/h, iso butane/olefin molar ratio of 15:1, and reaction time of 15 min). In addition, Urea-1.6AlCl 3 -0.13CuCl could be recycled and reused for at least 20 times without obvious loss in catalytic activity.
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2018
·
IF 0
Yuan Wang,Cailv Zheng,Yilin Wang,Hanxiang Chen,Yun Xu
A new kind of ionic liquids has been synthesized which comprised double bonds in the structure of anions (DB-ILs). Their physical properties, including densities, viscosities, activation energies and diffusion coefficients were determined. Temperature-dependent Krichevsky-Kasarnovsky (K-K) was used to deal with the data of solubility of CO 2 in DB-ILs, thermo-properties including solve enthalpy (ΔH sol ), entropy (ΔS sol ) and Gibbs free energy (ΔG sol ) were obtained. The research shows that DB-ILs perform well at the capturing CO 2 and can be regenerated four times.
✓ 已验证
产品关联
DOI
Royal Society Open Science
·
2018
·Vol. 5
·期 12
·
IF 2.504
Yi-Xin Sun,Ying-Ying Wang,Bing-Bing Shen,Bi-Xian Zhang,Xiao-Mei Hu
A series of dicationic ionic liquids (ILs) including [C4(MIM)2][PF6]2, [C5(MIM)2][PF6]2, [C6(MIM)2][PF6]2 and [C4(PYR)2][PF6]2 were synthesized. Their thermal stability and melting points were analysed. It was found that dicationic ILs presented important implications in the design of homogeneous and heterogeneous system with water. A homogeneous system of dicationic ILs with water could be formed at a relatively high temperature and then a heterogeneous system was formed when the solution was cooled to a low temperature. The ILs recovered by altering the temperature were obtained in high percentage yields of [C4(MIM)2][PF6]2 (97.6%), [C5(MIM)2][PF6]2 (97.3%), [C6(MIM)2][PF6]2 (98.0%) and [C4(PYR)2][PF6]2 (94.2%). On the other hand, [C4(MIM)2][PF6]2 and [C5(MIM)2][PF6]2 exhibited good solubility in acetonitrile and acetone. A homogeneous system could be achieved with imidazolium-based ILs with a relatively low amount of water and acetonitrile at room temperature. All of the properties of dicationic ILs have a strong correlation with the nature of dications, the linkage chain and the symmetry of dications. Dicationic ILs may provide a new opportunity for some specific applications in order to enable the effective separation and isolation of products.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Cleaner Production
·
2018
·
IF 5.651
Junli Wang,Shaojuan Zeng,Feng Huo,Dawei Shang,Hongyan He,Lu Bai,Xiangping Zhang,Jianwei Li
A large number of NH 3 emissions from industries, such as ammonia plant purge gas , tail gases of urea plants and ammonium molybdate plants, inevitably cause serious air pollution problems, such as fog and haze, which has raised extensive attentions worldwide. However, the commercial methods, like water scrubbing and acid scrubbing, substantially transfer the NH 3 pollute from gas phase to liquid or solid phase, which does not mean total elimination. How to realize efficiently separate and recover NH 3 form NH 3 -containing gas mixtures is still a great challenge. In order to develop efficient absorbents for NH 3 removal, a series of metal (copper (Cu), stannum (Sn), nickel (Ni), manganese (Mn), cadmium (Cd), zinc (Zn), ferrum (Fe)) ionic liquids (MILs) were synthesized, and their physicochemical properties and NH 3 absorption performance were systematically investigated. The results implied that the incorporation of metal center into ILs has a great effect on NH 3 absorption. Among the investigated MILs, bis(1-butyl-3-methyl imidazolium) copper tetrachloride salt ([Bmim] 2 [CuCl 4 ]) and bis(1-butyl-3-methyl imidazolium) stannum tetrachloride salt ([Bmim] 2 [SnCl 4 ]) show excellent NH 3 absorption capacities up to 0.172 gNH 3 ·gIL −1 and 0.106 gNH 3 ·gIL −1 , respectively, which are far more than most of the conventional ILs. Moreover, the high selectivity for NH 3 /N 2 , NH 3 /CO 2 and NH 3 /O 2 of [Bmim] 2 [CuCl 4 ] and [Bmim] 2 [SnCl 4 ] indicated that these MILs can selectively separate NH 3 from NH 3 -containing gases. The absorption mechanism was further studied using Fourier transform infrared (FT-IR) spectroscopy and quantitative chemical calculations. It was demonstrated that the chemical complexation between [Bmim] 2 [CuCl 4 ] and NH 3 plays a dominant role in NH 3 absorption, but the stronger hydrogen bonding between [Bmim] 2 [SnCl 4 ] and NH 3 enhances the absorption performance. In addition, [Bmim] 2 [SnCl 4 ] can keep good stability after five absorption and desorption cycles, implying this MIL shows great potentials as an efficient and reversible absorbent for NH 3 capture applications.
✓ 已验证
产品关联
DOI
高影响因子
MOLECULES
·
2014
·Vol. 19
·期 12
·20157-20169
·
IF 2.095
Caili Dai,Mingyong Du,Yifei Liu,Shilu Wang,Jianhui Zhao,Ang Chen,Dongxu Peng,Mingwei Zhao
Micelles formed by the long-chain piperidinium ionic liquids (ILs)N-alkyl-N-methylpiperidinium bromide of general formula CnPDB (n= 12, 14, 16) in ethylammonium nitrate (EAN) were investigated through surface tension and dissipative particle dynamics (DPD) simulations. Through surface tension measurements, the critical micelle concentration (cmc), the effectiveness of surface tension reduction (Πcmc), the maximum excess surface concentration (Гmax) and the minimum area occupied per surfactant molecule (Amin) can be obtained. A series of thermodynamic parameters (ΔGm0,ΔHm0andΔSm0) of micellization can be calculated and the results showed that the micellization was entropy-driven. In addition, the DPD simulation was performed to simulate the whole aggregation process behavior to better reveal the micelle formation process.Keywords:aggregation behavior;long-chain piperidinium ionic liquid;surface tension;dissipative particle dynamics
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Pharmaceutical Analysis
·
2013
·
IF 0
Nan Zhou,Xia-Shi Zhu
Ionic liquids functionalized β-cyclodextrin polymer, a mono-6-deoxy-6-(1,2-dimethylimidazolium)-β-cyclodextrin iodide polymer (ILs-β-CDCP), was synthesized as a solid-phase adsorbent coupled with high-performance liquid chromatography for separating or analyzing magnolol in drug samples. The results showed that magnolol was adsorbed rapidly on ILs-β-CDCP and eluted with methanol. Under the optimum conditions, preconcentration factor of the proposed method was 12. The linear range, limit of detection (LOD), correlation coefficient ( R ) and relative standard deviation (RSD) were found to be 0.02–8.00 μg/mL, 1.9 ng/mL, 0.9992 and 2.76% ( n =3, c =2.00 μg/mL), respectively. The interaction between ILs-β-CDCP and magnolol was studied through the inclusion constant, FTIR and TGA analysis. This proposed method has been successfully applied to the determination of magnolol in real samples.
✓ 已验证
产品关联
DOI
PubMed
International Journal of Polymer Science
·
2015
·
IF 1.195
Shi-Jia Dong,Bi-Xian Zhang,Yun-Fei Gao,Xiao-Mei Hu
Background and Aims. The complex structure of the lignocelluloses is the main obstacle in the conversion of lignocellulosic biomass into valuable products. Ionic liquids provide the opportunities for their efficient pretreatment for biomass. Therefore, in this work, pretreatment of corn stalk was carried out in ultrasonic-assisted ionic liquid including 1-butyl-3-methylimidazolium chloride [BMIM]Cl, 1-H-3-methylimidazolium chloride [HMIM]Cl, and 1-(1-propylsulfonic)-3-imidazolium chloride [HSO3-pMIM]Cl at 70°C for 2 h. We compared the pretreatments by ionic liquid with and without the addition of deionized water. Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were employed to analyze the chemical characteristics of regenerated cellulose-rich materials. Results. [HMIM]Cl and [HSO3-pMIM]Cl were effective in lignin extraction to obtain cellulose-rich materials. FTIR analysis and SEM analysis indicated the effective lignin removal and the reduced crystallinity of cellulose-rich materials. Enzymatic hydrolysis of cellulose-rich materials was performed efficiently. High yields of reducing sugar and glucose were obtained when the corn stalk was pretreated by [HMIM]Cl and [HSO3-pMIM]Cl. Conclusions. Ionic liquids provided the ideal environment for lignin extraction and enzymatic hydrolysis of corn stalk and [HMIM]Cl and [HSO3-pMIM]Cl proved the most efficient ionic liquids. This simple and environmentally acceptable method has a great potential for the preparation of bioethanol for industrial production.
✓ 已验证
产品关联
DOI
高影响因子
BIOCHEMICAL ENGINEERING JOURNAL
·
2016
·
IF 2.463
Yunchang Fan,Xing Dong,Yingying Zhong,Jing Li,Juan Miao,Shaofeng Hua,Yan Li,Boyu Cheng,Wenqiong Chen
In this work, the hydrolysis of casein by lumbrokinase in the presence of ionic liquids (ILs) was studied. The experimental results indicated that the effects of ILs on the casein hydrolysis depended on their concentrations; at low IL concentration, the addition of ILs could remarkably increase the lumbrokinase activity due to enhancing the hydrophilicity of casein by forming the IL-casein complex. However, at higher IL concentration, significant decrease in lumbrokinase activity was observed because the presence of ILs disturbed the hydrogen bond network in the active site of lumbrokinase. At the IL concentrations beyond their critical micelle concentrations, the incorporation of substrate into the micellar pseudo-phase also contributed to the decrease in lumbrokinase activity. When a more hydrophilic substrate was adopted, the effects of ILs on the lumbrokinase activity were negative in all cases. Fluorescence analysis indicated that hydrogen bonding was the main driving force ruling the interaction of ILs and lumbrokinase.
✓ 已验证
产品关联
DOI
高影响因子
ChemSusChem
·
2016
·Vol. 9
·期 8
·806-812
·
IF 7.116
Qiwei Yang,Zhiping Wang,Zongbi Bao,Zhiguo Zhang,Yiwen Yang,Qilong Ren,Huabin Xing,Sheng Dai
Graphical Soak it up : The electrostatic environment around amine groups in ionic liquids (ILs) has critical influence on their CO 2 absorption mechanism, which enables the achievement of higher CO 2 capacity by tuning the local structure around the amine. Moreover, this work indicates that the actual CO 2 absorption mechanism by amino-acid ILs goes beyond the apparent CO 2 /amine stoichiometry. The last decade saw an explosion of interest in using amine-functionalized materials for CO 2 capture and conversion, and it is of great importance to elucidate the relationship between the molecular structure of amine-functionalized materials and their CO 2 capacity. In this work, based on a new quantitative analysis method for the CO 2 absorption mechanism of amino-acid ionic liquids (ILs) and quantum chemical calculations, we show that the small difference in the local structure of amine groups in ILs could lead to much different CO 2 absorption mechanisms, which provides an opportunity for achieving higher CO 2 capacity by structure design. This work revealed that the actual CO 2 absorption mechanism by amino-acid ILs goes beyond the apparent CO 2 /amine stoichiometry; a rigid ring structure around the amine group in ILs creates a unique electrostatic environment that inhibits the deprotonation of carbamic acid and enables actually equimolar CO 2 /amine absorption.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）