RSC Advances
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2013
·Vol. 4
·期 5
·2360-2367
·
IF 2.562
Jin-Quan Wang,Wei-Guo Cheng,Jian Sun,Tian-Yuan Shi,Xiang-Ping Zhang,Suo-Jiang Zhang
Several novel 2-hydroxymethyl-functionalized ILs act as the catalysts for synthesis of cyclic carbonates from CO2 and epoxides without the use of any co-catalysts or organic solvent. Moreover, the 2-hydroxymethyl-functionalized ILs were compatible with base, which combined with K2CO3 were used as effective catalytic system for green synthesis of dimethyl carbonate from CO2via ethylene carbonate without catalyst separation. Additionally, the mechanistic details of the fixation of CO2 into cyclic carbonate catalyzed by 2-hydroxymethyl-functionalized ILs were also elucidated by density functional theory. The process reported here represents a simple, ecologically safer, cost-effective and energy-saving route to organic carbonates from CO2.
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高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2014
·
IF 2.235
Penglei Cui,Hongyan He,Dong Chen,Hui Liu,Suojiang Zhang,Jun Yang
The synthesis of noble metal nanoparticles (NMNPs) using, or in the presence of, ionic liquids (ILs) represents a burgeoning direction in materials chemistry. Processing these nanomaterials synthesized in ILs would be drastically simplified if they could be routinely dispersed into a wide variety of polar/nonpolar solvents. We herein demonstrate the phase transfer of the as-prepared nanoparticles from ILs to an organic or aqueous medium. The protocol involves first mixing the noble metal sols in ILs and an ethanolic or a methanolic solution of transfer agent and then extracting the transfer-agent-stabilized NMNPs into toluene or aqueous phase. Electron micrographs reveal that the particles are fully dispersed after transfer, and the size/morphology of the NMNPs could be significantly tuned by the ILs. In particular, electrochemical measurements of the Pt nanoparticles upon methanol oxidation reaction demonstrate that the particles are dominated by low-index crystal planes.
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GREEN CHEMISTRY
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2013
·Vol. 16
·期 3
·1326-1335
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IF 6.828
Benlian Lu,Airong Xu,Jianji Wang
As a kind of promising solvents, ionic liquids (ILs) have been used to dissolve cellulose and great progress has been made in recent years. However, the dissolution mechanism, especially the role of cations of ILs in the dissolution of cellulose, is still in debate. In this work, 13 kinds of ILs with a fixed anion [CH3COO]− but varied cationic backbones and alkyl chains have been prepared and characterized. The solubilities of cellulose in these ILs were measured at different temperatures. This allowed us to systematically study the effect of cationic structures on the cellulose dissolution at a given temperature. In order to investigate the dissolution mechanism, Kamlet–Taft parameters of these ILs in the temperature range from 25 to 65 °C and 13C NMR spectra of 1-benzyl-3-methylimidazolium acetate ([phC1mim][CH3COO]) + cellulose systems at 90 °C were also determined. It was found that acidic protons on the heterocyclic rings of the cations are essential for the dissolution of cellulose in the ILs, but the van der Waals interaction of cation with cellulose is not important. These protons may form C–H⋯O hydrogen bonds with hydroxyl and ether oxygen of cellulose to increase cellulose solubility. Cations of the ILs may also decrease cellulose solubility by strong interaction with anions or steric hindrance effect of large size group in their alkyl chains. These interactions together with strong O–H⋯O hydrogen bonds between the anion and hydroxyl protons of cellulose resulted in the disruption of the inter- and intra-molecular hydrogen bonds and thus effective dissolution of cellulose.
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高影响因子
INDUSTRIAL CROPS AND PRODUCTS
·
2013
·
IF 2.468
Zhao Hu,Bing Liu,Zehui Zhang,Lianqing Chen
An efficient process was developed for the conversion of carbohydrates into 5-hydroxymethylfurfural (HMF) using DMSO as the solvent and an acidic ionic liquid 1-carboxypropyl-3-methyl imidazolium chloride ([CMIm]Cl) as the catalyst. The effects of various reaction parameters on HMF yields were investigated. HMF yields of 95.7% and 88.4% were obtained from fructose and inulin when reactions were carried out 120 °C after 120 min and 180 min, respectively. The combination of ZrOCl 2 and [CMIm]Cl resulted in a 50.6% yield of HMF from glucose. HMF could also be synthesized using other carbohydrates with moderate to high yields.
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ENERGY & FUELS
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2015
·
IF 2.79
Pengcheng Hu,Rui Zhang,Zhichang Liu,Haiyan Liu,Chunming Xu,Xianghai Meng,Meng Liang,Shuangshuang Liang
Several amine-based ionic liquids (ILs) were synthesized via a one-step method using low-priced organic amines and inorganic acids, and they were mixed with water to form new CO2 absorbents. The effects of the ionic structure, IL concentration, temperature, and pressure on the CO2 absorption performance were investigated. The absorption performance of ILs was closely related to the ionic structure, and the CO2 molar absorption capacity in ILs with the same cation followed the order of [NO3] > [BF4] > [SO4] or [HSO4], whereas that with the same anion ranked in the following order: multiple amine > diamine > monoamine. The IL [TETA][NO3] with 40 wt % concentration showed the best capacity for CO2 absorption. Moreover, low temperature and high pressure favored CO2 absorption. The reaction mechanism of the amine group with CO2 in aqueous solutions of [TETA][NO3], primary amine, and secondary amine was studied via in situ infrared (IR) spectrophotometry. The results showed that the primary and secondary amines first reacted with CO2 to form carbamate, which decomposed further into bicarbonate with the continuous addition of CO2. However, carbamate generated from the reaction of [TETA][NO3] with CO2 did not decompose further.
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JOURNAL OF CHEMICAL THERMODYNAMICS
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2015
·
IF 2.679
Fufeng Cai,Guomin Xiao
In this work, the feasibility of ionic liquids (ILs), 1,3-dimethylimidazolium dimethylphosphate ([MMIM][DMP]), 1-ethyl-3-methylimidazolium diethylphosphate ([EMIM][DEP]), and 1-butyl-3-methylimidazolium dibutylphosphate ([BMIM][DBP]), as solvents for the extraction of methanol from its mixtures with hexane and heptane was analyzed. The knowledge of (liquid + liquid) equilibria (LLE) of these mixtures is necessary for the design of the extraction separation process. Hence, the LLE data for the ternary systems, {methanol + hexane + ([MMIM][DMP], or [EMIM][DEP], or [BMIM][DBP])}, and {methanol + heptane + ([MMIM][DMP], or [EMIM][DEP], or [BMIM][DBP])}, were measured at T = 298.2 K and atmospheric pressure. The experimental results were correlated with the thermodynamic nonrandom two-liquid (NRTL) model. The solute distribution ratios of methanol and methanol/alkane selectivities, derived from the experimental LLE data, were calculated and analyzed to evaluate the capability of the studied ILs to accomplish the separation target. Meanwhile, these capabilities were also compared with that of other ILs obtained from the literature.
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AICHE JOURNAL
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2015
·Vol. 61
·期 6
·2028-2034
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IF 2.748
Kaihong Chen,Wenjun Lin,Xini Yu,Xiaoyan Luo,Fang Ding,Xi He,Haoran Li,Congmin Wang
Five kinds of anion-functionalized ionic liquids (ILs) with different basicity and substituent were selected, prepared and applied in the capture of SO 2 from flue gas, where the concentration of SO 2 is only 2000 ppm. The effect of the anion on SO 2 absorption capacity, desorption residue, and available absorption capacity under 2000 ppm was investigated. The relationship between available absorption capacity and absorption enthalpy was also studied. Through a combination of thermodynamic analysis and quantum calculation, the results indicated that the effect of the cation in the IL on absorption enthalpy was significant. However, the effect of chain length in the cation was weak. Hence, a new IL with low molecular weight, [P 4442 ][Tetz], was further designed and applied for the capture of SO 2 , which shows the high absorption capacity of 0.18 g SO 2 per g IL and excellent reversibility for 2000 ppm SO 2 . © 2015 American Institute of Chemical Engineers AIChE J , 61: 2028–2034, 2015
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ACS Sustainable Chemistry & Engineering
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2015
·
IF 4.642
Yuanbang Xie,Huabin Xing,Qiwei Yang,Zongbi Bao,Baogen Su,Qilong Ren
Ionic liquid-based aqueous biphasic systems (IL-based ABSs) offer a benign alternative process for conventional extraction systems with volatile organic solvents to separate biomass. Designing an IL-based ABS with excellent phase splitting ability, remarkable extraction efficiency, and good biocompatibility remains challenging. In this work, we report a series of novel ABSs using biocompatible ILs composed of long chain carboxylate anions and a cholinium cation that are all derived from biomass. This strategy introduced long alkyl chains into the anions, which not only significantly increased the hydrogen bond (HB) acceptor ability of the carboxylate anions through a remarkable electron-donating effect but also ensured good hydrophobicity for achieving better phase splitting. The developed IL-based ABS demonstrated a relatively broad biphasic area and extraordinary extraction efficiency for amino acids and bioactive compounds with distribution coefficients for tryptophan, phenylalanine, and caffeine of 58.5, 120 (120 was set as a maximum value for the partition coefficient because in some cases the concentration of the extracted material in the salt-rich phase was below the limit of detection), and 120, respectively, which were remarkably higher than those obtained in ABS with conventional ILs. This work shows that the long chain carboxylate anion is critical for the excellent extraction performance of the developed ABS and that their distribution coefficients increased with increasing anion alkyl chain lengths. In addition, liquid crystal structures were observed when the carbon number of the carboxylate anion of the ILs exceeded eight; thus, IL-based ABS with liquid crystal structures were reported for the first time.
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JOURNAL OF HAZARDOUS MATERIALS
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2014
·
IF 4.331
Shidong Tian,Yucui Hou,Weize Wu,Shuhang Ren,Jianguo Qian
The capture of SO 2 by ionic liquids (ILs) has drawn much attention all over the world. However, ILs can absorb not only SO 2 but also water from flue gas. The removal of water from ILs is necessary for reusing the absorbent. In order to reduce the energy costs of removing water, it would be helpful to weaken the interactions between ILs and water. In this work, two kinds of hydrophobic task-specific ILs, 1-(2-diethyl-aminoethyl)-3-methylimidazolium hexafluorophosphate ([Et 2 NEmim] [PF 6 ]) and 1-(2-diethyl-aminoethyl)-1-methylpyrrolidinium hexafluorophosphate ([Et 2 NEmpyr][PF 6 ]), were designed and synthesized. Thermal stability and physical properties of the ILs were studied. Furthermore, the application of the ILs for the capture of SO 2 and the absorption mechanism were systematically investigated. It has been found that both of the ILs are immiscible with water, and [Et 2 NEmim][PF 6 ] has much lower viscosity, much higher thermal stability and much higher SO 2 absorption rate than [Et 2 NEmpyr][PF 6 ]. [Et 2 NEmim][PF 6 ] shows high SO 2 absorption capacities up to 2.11 mol SO 2 per mole IL (pure SO 2 ) and 0.94 mol SO 2 per mole IL (3% SO 2 ) under hydrous conditions at 30 °C. The result suggests that [Et 2 NEmim][PF 6 ] is a promising recyclable absorbent for the capture of SO 2 .
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PubMed
高影响因子
KOREAN JOURNAL OF CHEMICAL ENGINEERING
·
2014
·Vol. 31
·期 8
·1377-1383
·
IF 1.241
Ouyang Fan,Zhou Yan,Li Zhang-Min,Hu Na,Tao Duan-Jian
Five tetrabutylphosphonium amino acid ionic liquids ([P 4444 ][AA]) were prepared, characterized, and used as catalysts for solvent-free Knoevenagel condensation reactions. The tetrabutylphosphonium prolinate ([P 4444 ][Pro]) showed excellent catalytic activity and selectivity in Knoevenagel condensation reactions of active methylene compounds with various aromatic aldehydes, and all the yields of corresponding products were more than 85% under mild conditions. Furthermore, a plausible reaction mechanism for the excellent performance of [P 4444 ][Pro] has been proposed, and [P 4444 ][Pro] could be used repetitively at least six times without obvious decrease in activity and quantity.
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Journal of Materials Chemistry C
·
2017
·Vol. 5
·期 20
·4951-4958
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IF 5.256
Xiaofeng Sun,Keyang Yin,Baoyong Liu,Shengju Zhou,Jiamei Cao,Geping Zhang,Hongguang Li
Carbon quantum dots (CQDs) have appeared as attractive photoluminescent (PL) materials that overcome the poor photostability of organic dyes and the environmental hazards of heavy metal-containing quantum dots. Engineering CQDs into PL inks that can find applications in anti-counterfeiting and information encryption is promising. However, current methodologies are limited by several disadvantages, including blocking of the writing/printing tools caused by the slow evaporation of the solvent and the aggregation-induced quenching of CQDs in their dry state, when practical applications are concerned. Herein, a new generation of CQD-based PL inks applying room-temperature ionic liquids (RTILs) as the solvent was prepared. The concept presented herein relies on functionalizing the CQDs with the same or similar cationic moieties as those involved in RTILs and facilely obtaining the PL inks through a one-step phase transfer of the as-prepared water-soluble CQDs to the hydrophobic RTILs. The so-obtained CQDs/RTILs inks are highly photoluminescent and compatible with most commonly used writing and templating tools including gel ink pens, brush pens and stamps. Letters or patterns obtained by these PL inks show impressive photostability under various harsh conditions.
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JOURNAL OF POWER SOURCES
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2016
·
IF 6.333
Tianqiao Yong,Lingzhi Zhang,Jinglun Wang,Yongjin Mai,Xiaodan Yan,Xinyue Zhao
Three choline-based ionic liquids functionalized with trimethylsilyl, allyl, and cynoethyl groups are synthesized in an inexpensive route as safe electrolytes for high-voltage lithium-ion batteries. The thermal stabilities, viscosities, conductivities, and electrochemical windows of these ILs are reported. Hybrid electrolytes were formulated by doping with 0.6 M LiPF6/0.4 M lithium oxalydifluoroborate (LiODFB) as salts and dimethyl carbonate (DMC) as co-solvent. By using 0.6 M LiPF6/0.4 M LiODFB trimethylsilylated choline-based IL (SN1IL-TFSI)/DMC as electrolyte, LiCoO2/graphite full cell showed excellent cycling performance with a capacity of 152 mAh g -1 and 99% capacity retention over 90 cycles at a cut-off voltage of 4.4 V. The propagation rate of SN1IL-TFSI)/DMC electrolyte is only one quarter of the commercial electrolyte (1 M LiPF6 EC/DEC/DMC, v / v / v = 1/1/1), suggesting a better safety feature.
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高影响因子
危险品化学品经营许可证（带存储）