Chemistry-An Asian Journal
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2018
·Vol. 13
·期 15
·1932-1940
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IF 3.692
Nianming Jiao,Yanqiang Zhang,Hao Li,Long Liu,Suojiang Zhang
Graphical Yes, it is rocket science ! Both the cations and the anions of hypergolic ionic liquids, [bis(imidazolyl)–BH 2 ] + [bis(triazolyl)–BH 2 ] − (see figure), were functionalized with B−H groups and azoles, which play the roles of ‘hypergolic triggers’ and ‘regulators’, respectively. These ionic liquids show great promise as sustainable rocket fuels. [Bis(imidazolyl)–BH 2 ] + [bis(triazolyl)–BH 2 ] − and [bis(imidazolyl)–BH 2 ] + [tris(triazolyl)–BH] − were synthesized, the cations and anions of which were functionalized with B−H groups and azoles. As B−H groups contribute to the hypergolic activity and azole groups improve the energy output, the resulting ionic liquids exhibited ignition delay times as low as 20 ms and energy outputs as high as 461.1 kJ mol −1 . In addition, densities (1.07–1.22 g cm −3 ) and density-specific impulse (≈360 s g cm −3 ) values reached a relatively high level. These ionic liquids show great promise as sustainable rocket fuels.
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高影响因子
WOOD SCIENCE AND TECHNOLOGY
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2018
·Vol. 53
·期 1
·177-189
·
IF 1.706
Liu Chao,Li Youming,Hou Yi
Three basic ionic liquids (BILs), 1,3-dimethyl-imidazole dimethyl phosphate([MMIM][DMP]), 1-butyl-3methylimidazolium acetate([BMIM][Ac]) and 1-ethyl-3-methylimidazolium acetate([EMIM][Ac]), were applied to the pretreatment of eucalyptus biomass under microwave conditions with the decreasing alkalinity order of [EMIM][Ac] > [BMIM][Ac] > [MMIM][DMP]. The results showed that the alkalinity of ionic liquids has great effects on the pretreatment of biomass; the greater the alkalinity is, the more capable are the ionic liquids to dissolve hemicellulose, and [MMIM][DMP] with moderately weak alkalinity has a uniquely stronger ability to remove lignin from biomass. Dissolved lignin could easily be separated by using the acetone/water (1:1, v/v), and [MMIM][DMP] pretreatment can extract 41.8% of the total amount of eucalyptus lignin, of which [BMIM][Ac] and [EMIM][Ac] recovered 18.2% and 10.7% of the total amount of raw lignin, respectively. The untreated and ILs-treated eucalyptus samples were characterized by FTIR, XRD, TGA and SEM. Lower thermal stability and changes in crystal structure were observed after pretreatments.
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高影响因子
ENERGY & FUELS
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2018
·
IF 3.024
Jie Li,Yong Kang,Bohao Li,Xin Wang,Dan Li
In this work, four novel PEG-linked dicationic ionic liquids (DILs) with one kind of thiocyanate anion and chloride anion and a traditional DIL with thiocyanate anion were synthesized and used for SO2 absorption. The physicochemical properties of PEG-linked DILs with thiocyanate anion were measured. The performance of SO2 absorption by the five DILs at different pressures, temperatures, and water contents was also investigated. The results showed that the absorption process was fast and the absorption capacities of the DILs were much higher than those of monocationic ILs; especially, [E3Eim2][Cl]2 had the absorption capacity up to 6.779 mol SO2/mol IL at 20 °C and 1 bar. The mechanism of SO2 absorption by DILs was also studied with FT-IR and NMR, which revealed there just existed physical interaction between DILs and SO2. PEG-linked DILs have a high selectivity between SO2 and CO2. Meanwhile, the good absorption performance of PEG-linked DILs could be maintained after five successive absorption/desorption cycles, implying these ILs show great potential as candidate absorbents for SO2 absorption.
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高影响因子
CHEMICAL ENGINEERING & TECHNOLOGY
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2018
·Vol. 42
·期 1
·174-181
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IF 1.588
Fangxia Yang,Junhua Zhang,Yingjie Guo,Lele Feng,Shijun Wei,Shuai Chen
Three Brønsted acidic imidazole dicationic ionic liquids (ILs) with different length of alkyl chains, [C n (Mim) 2 ][HSO 4 ] 2 ( n = 3, 6, 12), were prepared and used as catalyst for the esterification reaction of free fatty acids and methanol. Taking oleic acid as model acid, the catalytic performances of the synthesized ILs for the esterification were evaluated. The main physicochemical properties of the ILs, thermal stability, acidity, solubility in common solvents, and causticity on Austenitic stainless steel 316, were examined. [C 3 (Mim) 2 ][HSO 4 ] 2 demonstrated the highest catalytic activity and enabled to assess the preliminary optimum esterification condition of oleic acid and methanol. Under optimized reaction conditions, the yield of oleic acid methyl ester was up to 95 %. The ILs have great potential as catalysts for producing fatty acid methyl esters from long-chain free fatty acids.
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高影响因子
ENERGY & FUELS
·
2018
·
IF 3.024
Youan Ji,Yucui Hou,Shuhang Ren,Congfei Yao,Weize Wu
Phenols have wide applications and much commercial value, and they are obtained from oil mixtures by separation. However, the previous separation agents have low separation efficiency or corrosive halide ions or are difficult to be regenerated. In this work, we designed several tetraethylammonium amino acid (TAAA) ionic liquids (ILs) without corrosive halide ions and found that the ILs could separate phenols from oil mixtures with much higher extraction efficiency and could be regenerated using CO2. The effects of separation time, initial phenol content, TAAA type, water content in TAAA, and phenol type on separation were investigated. It has been found that TAAA can separate phenols with high separation efficiencies, and the maximum separation efficiency of phenol can reach up to 99.0% at a TAAA:phenol mole ratio of 0.60. Meanwhile, ultimate phenol contents can reach as low as 1.40 g/dm3. The initial phenol content almost has no influence on the ultimate phenol contents. For real coal tar oil mixtures, the separation efficiency of phenols can reach up to 98.6%. The TAAAs can be regenerated and reused without significant decreases in separation efficiency of phenols. The separation mechanism has also been proposed based on chemical reactions.
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高影响因子
JOURNAL OF MOLECULAR LIQUIDS
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2018
·
IF 4.513
Yunlei Shi,Dazhen Xiong,Yongkui Chen,Huiyong Wang,Jianji Wang
Stimuli-responsive Pickering emulsions have attracted increasing interest because of the advantages of applications in numerous industrial processes. In this work, Pickering emulsions have been obtained by using negatively charged silica nanoparticles in association with very small amount of CO 2 -responsive ionic liquids as stabilizer. Ionic liquids N -alkylimidazole bicarbonates ([C n im] + HCO 3 − , n = 6, 8, 10, 12, 14) are in-situ generated by bubbling CO 2 into aqueous solution of N -alkylimidazoles (C n im, n = 6, 8, 10, 12, 14), and this process is reversible by removal of CO 2 with bubbling of N 2 . Thus the Pickering emulsions may be switched multiple times between emulsification and demulsification states by alternatively bubbling and removal of CO 2 at 25 °C. The effect of concentration and alkyl chain length of [C n im] + HCO 3 − on Pickering emulsions is investigated systematically, and the possible mechanism of CO 2 -responsive Pickering emulsion is also studied by conductivity, surface tension, zeta potential , adsorption isotherm , water contact angle and 13 C NMR spectroscopy. This CO 2 -responsive Pickering emulsion is cheap, simple, eco-friendly, and may have potential applications in emulsification and demulsification.
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高影响因子
ACS Sustainable Chemistry & Engineering
·
2019
·
IF 6.97
Hui Yu,Ke Cui,Tenghui Li,Zidong Zhang,Zhiyong Zhou,Zhongqi Ren
Biobutanol has a high energy density, good miscibility with gasoline, and a low environmental impact; therefore, it is a possible substitute or additive for gasoline. Because biobutanol is typically obtained through so-called ABE fermentation, the effective separation of butanol from the product mixture is important. Ionic liquids (ILs) have been used as extractants, and tailoring the IL structure to promote hydrogen bonding with butanol could improve the extraction performance. In the present work, an amine group was added to the imidazole cation of an IL, paired with bis(trifluoromethylsulfonyl)imide as the anion. Hydroxyl groups were added to the 1,8-diazabicyclo-[5.4.0]-undec-7-ene cation, and an imidazolium-based IL was produced by combining hydroxyl with imidazole. The structures of these three ILs were verified by 1H nuclear magnetic resonance and Fourier transform infrared spectroscopic analyses. The binding energies between these substances and butanol, acetone, and ethanol were calculated using the Gaussian software package based on density functional theory. The results indicated that the interaction energies between N,N-bis(2-hydroxypropyl)octan-1-aminium hydroxide imidazole ([C8DIPA][Im]) and butanol, acetone, and ethanol are greater than that with water. These ILs were examined as extractants for the separation of butanol, acetone, or ethanol with water, and the [C8DIPA][Im] exhibited the best performance. Effects of extraction time, extraction temperature, and IL proportion on extraction rate were assessed, and this IL extracted 78%, 34%, and 6% of the three components, respectively. This performance remained stable after 10 recycling trials, and [C8DIPA][Im] was also used to separate the products in an actual ABE fermentation mixture.
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高影响因子
AICHE JOURNAL
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2018
·Vol. 65
·期 1
·230-238
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IF 3.326
Xiao Y. Luo,Xiao Y. Lv,Gui L. Shi,Qin Meng,Hao R. Li,Cong M. Wang
Generally, amine group captures CO 2 according to 2:1 or 1:1 stoichiometry. Here, we report a kind of improved carbon capture using amino-functionalized ionic liquids (ILs) through 1:2 stoichiometry. A serial of amino-functionalized ILs various with basicity and steric hindrance of anion were designed, prepared, and applied in CO 2 capture. Through a combination of absorption experiment, quantum chemical calculation, spectroscopic investigation and calorimetric method, the results indicated that one amine group could bind two CO 2 through proton transfer (PT) process and intramolecular hydrogen bond formation, which leading to enhanced capacity that breaks through equimolar. The basicity and steric hindrance of anion play a significant role in promoting amine group to capture two CO 2 . [P 66614 ] 2 [Asp] with dual anion was further designed and synthesized to promote PT process, which showed high capacity of 1.96 mol/mol IL at 30°C and 1 atm as well as excellent reversibility. © 2018 American Institute of Chemical Engineers AIChE J , 65: 230–238, 2019
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高影响因子
APPLIED ENERGY
·
2018
·
IF 7.9
Min Xiao,Helei Liu,Hongxia Gao,Wilfred Olson,Zhiwu Liang
In this work, nonaqueous binary absorbents were investigated for CO 2 capture by mixing conventional amines (i.e. monoethanolamine MEA, methyldiethanolamin MDEA) and ionic liquids. Four ionic liquids [BMIM]BF 4 , [BEIM]BF 4 , [BPIM]BF 4 and [BBIM]BF 4 were synthesized. The thermal stability of the ionic liquids was evaluated and viscosity was measured over the temperature range of 298–348 K. The CO 2 absorption performance of the pure ionic liquids was studied at ambient pressure and compared with the hybrid absorbents. The influence factors including temperature, stir rate and cycling numbers were then investigated. Finally, the CO 2 absorption mechanism was verified using NMR spectroscopy. Results showed that additional amine could greatly promote the CO 2 absorption performance of ionic liquids and mixed absorbents revealed different CO 2 absorption behavior depending on the amine type. This work proved that the mixed absorbent MDEA + [BEIM]BF 4 yields high cycling CO 2 capacity, energy saving, good regenerability and especially, low viscosity.
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高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
·
2013
·
IF 2.297
Jun Jing,Zhiyong Li,Yuanchao Pei,Huiyong Wang,Jianji Wang
In this work, a series of novel room temperature ionic liquids (ILs) have been synthesized with cheap, naturally α-amino acid ester as cations and bis(trifluoromethylsulfonyl)imide as anion. The glass transition temperature and thermal decomposition temperature of these ILs, partition coefficients of some coumarins and purine alkaloids between water and the amino acid ester-based ILs at T = 298.15 K, and Gibbs energy, enthalpy and entropy changes for the transfer of caffeine and 6,7-dihydroxycoumarin from water to [LeuC 2 ][Tf 2 N] have been determined. It is shown that these ILs are highly effective materials for the extraction of drug compounds like coumarin, 4-hydroxycoumarin, 7-hydroxycoumarin, 3-aminocoumarin, coumarin-3-carboxylic acid, 6,7-dihydroxycoumarin, 6,7-dihydroxy-4-methylcoumarin, caffeine, theobromine, theophylline, inosine, and 2,6-diaminopurine. The partition process is driven by enthalpy term, and partition coefficients of the drug molecules increase with the increase of hydrophobicity of both the drug molecules and the ILs. Furthermore, the possible partition mechanism has been investigated from 13 C NMR measurements.
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高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2013
·
IF 3.473
Dishun Zhao,Mengshuai Liu,Juan Zhang,Junpan Li,Peibing Ren
Three kinds of imidazole based dicationic [C 2 (Mim) 2 ], [C 3 (Mim) 2 ], [C 4 (Mim) 2 ] with traditional counter anion HSO 4 - ionic liquids (ILs) were synthesized. Key physicochemical properties, such as thermal stability, solubility in common solvents, acidic property and corrosion of ILs for Austenitic stainless steel 316 were determined. Esterification of alcohols by carboxylic acids has been carried out at room temperature in a group of imidazole dicationic ionic liquid. The catalytic performance was found to be much better than that of conventional non-cation functionalized ionic liquids and the corrosion was five times weaker than sulfuric acid. The esters were easily recovered due to immiscibility with the ionic liquid and reported imidazole dicationic ionic liquids were a promising catalyst for esterification reaction.
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高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2014
·
IF 2.613
Zhichang Liu,Pengcheng Hu,Xianghai Meng,Rui Zhang,Huiqing Yue,Chunming Xu,Yufeng Hu
Switchable polarity ionic liquids (SWILs) with low moisture sensitivity were successfully synthesized from organic amidine/fluoroalcohol and guanidine/fluoroalcohol via proton transfer reaction. The ionic liquids showed low polarity and could be converted into high-polarity fluoroalkylcarbonate ILs upon the treatment with CO 2 under mild conditions. Their high polarity state could also readily be reverted to the low polarity state by the removal of CO 2 with heating. Changes in the structures and physical properties resulting from the change from low polarity to high polarity were confirmed by NMR spectroscopy, FTIR spectrophotometry , UV–vis spectroscopy, and conductivity and miscibility measurements. These SWILs have potential applications in solute separation and solvent recovery.
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高影响因子
危险品化学品经营许可证（带存储）