GREEN CHEMISTRY
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2019
·Vol. 21
·期 11
·3182-3189
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IF 9.405
Xiaocheng Lin,Xiaomei Ling,Jinyi Chen,Meichen Li,Tongwen Xu,Ting Qiu
Different from the common ionic liquids (ILs) as homogeneous catalysts, solid ionic liquids (SILs) as heterogeneous catalysts are simply fabricated herein via an efficient one-step reaction for biodiesel production. Specifically, low-cost aliphatic amines containing secondary and/or primary amine groups are selected as the starting materials followed by the reaction with 1,3-propane sultone under mild conditions to graft sulfonic acid (–SO3H) groups onto the final products. The –SO3H groups are divided into two types: the bonding –SO3H groups (zwitterion arising from the hydrogen bond between sulfonic acid groups and amine groups) make the products turn solid while the free –SO3H groups endow the products with catalytic activity. Such solid ionic liquids (SILs) present pronounced activity, excellent stability and reusability as heterogeneous catalysts in esterification of free fatty acids (FFAs), indicating great potential in biodiesel production because of their high performance and low cost.
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MOLECULES
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2018
·Vol. 23
·期 9
·2154
·
IF 3.098
Yunchang Fan,Dongxu Cai,Xin Wang,Lei Yang
Recently, ionic liquids (ILs) have been regarded as ideal media for non-aqueous bio-catalysis. In this work, the synthesis of warfarin by the lipase-catalyzed Michael addition in IL media and the parameters that affected the warfarin yield were investigated. Experimental results demonstrated that the chemical structures of the ILs were a major factor for influencing the warfarin yield. The ILs containing the NTf2–anion were suitable reaction media due to the high chemical stability of this anion. The incorporation of the hydroxyl group on the IL cation significantly improved the lipase activity due to the H2O-mimicking property of this group. The lipase activity decreased by increasing the alkyl chain length on the IL cation due to the non-polar domain formation of the IL cation at the active site entrance of lipase. The ILs and lipase could be reused no less than five times without reduction in the warfarin yield.Keywords:ionic liquids (ILs);lipase;Michael addition;warfarin;bio-catalysis
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SEPARATION SCIENCE AND TECHNOLOGY
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2013
·
IF 1.164
Guangfei Qu,Jun Zhang,Junyan Li,Ping Ning
Two kinds of phosphate ionic liquids were synthesized and their SO2 absorption performance was investigated. It was found that both ionic liquids could readily absorb SO2, and the absorption capacity could reach 2.8 and 2.7 mol SO2 per mole ILs, respectively, at ambient temperature and under normal pressure. Moreover, the cycle of SO2 absorption and desorption from ionic liquids was repeated for four times and no change in the absorption capacity was observed. FT-IR spectrum and 1H NMR were used to characterize the microstructure of SO2-absorbed ILs and ILs, analysis showed that both ionic liquids absorbed SO2 purely by physical absorption. Comparing with the previous reported ionic liquids such as [Bmim][PF6] and [Emim][BF4], the synthesized ionic liquids showed higher absorption capacity, due to the anion based phosphate (O˭P‒O) with the free electrons on the oxygen interacting with the Lewis acidic sulfur of SO2, and then showing a great affinity for SO2.
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INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2013
·
IF 2.206
Yucui Hou,Yuehong Ren,Wei Peng,Shuhang Ren,Weize Wu
Phenolic compounds, which are important substances in industry, are mainly derived from coal liquefaction oil, coal tar, and petroleum, and also from biomass via pyrolysis. However, the traditional process of separation of phenols from oil using water, NaOH, and H2SO4 causes serious environmental problems. In this work, imidazolium-based ionic liquids (ILs) were used to extract phenol from a model oil of hexane and phenol in order to reduce environmental risk. It was found that these ILs could successfully separate phenols from hexane, and a small amount of [Bmim]Cl, equimolar to that of phenol in hexane, was enough to extract phenol with a high extraction efficiency of 99%. Anions of imidazolium-based ILs have a significant influence on the phenol extraction efficiency, which follows the order: Cl– > Br– > BF4– > PF6–. But the cation of these ILs shows a relatively small influence on the extraction. Particularly, [Bmim]Cl shows best performance in terms of phenol extraction efficiency. Furthermore, it is not sensitive to temperature changes and can be performed at ambient temperature. The extracted phenol in ILs could be recovered by evaporation, and the regenerated ILs could be reused for four cycles with no obvious loss in the phenol extraction efficiency. [Bmim]Cl was also used to extract phenols from real coal liquefaction oil, and the extraction efficiency of phenols could reach 90%.
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CHINESE CHEMICAL LETTERS
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2015
·
IF 1.587
Teng-Jie Ren,Juan Zhang,Yan-Hui Hu,Jun-Pan Li,Meng-Shuai Liu,Di-Shun Zhao
Several metal-based ionic liquids (ILs) were synthesized and used as extractants for the desulfurization of dibenzothiophene (DBT) in simulated fuel oil. The effects of several anion and metal ions, n (ILs)/ n (metal) as mole ratio, V IL / V oil and extractive times on the removal ratio of DBT were investigated in detail. The results showed that [BMIM]HSO 4 /FeCl 3 (BMIM was short for 1-butyl-3-methyl imidazole) was superior to the other ILs for the extractive desulfurization. A total of 100% of DBT was removed at room temperature in 5 min with V [ BMIM ] HSO 4 / FeCl 3 / V oil = 1 : 1 . The extractive activity of [BMIM]HSO 4 /FeCl 3 IL did not change almost after five runs. Extractive desulfurization of different sulfur compounds and commercial diesel fuel oil were also examined. The removal ratios of the sulfur compounds as the reaction substrates were all over 90% and the sulfur content of commercial diesel oil decreased to 120 ppm from 12,400 ppm.
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TRIBOLOGY INTERNATIONAL
·
2017
·
IF 2.903
Rui Dong,Ping Wen,Shuai Zhang,Chaoyang Zhang,Wenjing Sun,Mingjin Fan,Desuo Yang,Feng Zhou,Weimin Liu
A series of dicarboxylic acid ionic liquids (DAILs) were synthesized from the neutralizing reaction of variable dicarboxylic acids with tetrabutylammonium hydroxide. The ionic liquids (ILs) exhibit good performance in terms of corrosion, viscosity–temperature characteristic, and thermal and hydrolysis stabilities. Tribological test results indicated that these DAILs possess superior behavior in reducing both the friction coefficient and wear volume compared with monocarboxylic acid ionic liquids (MAILs), especially when used on steel–copper and steel–aluminum friction pairs . The enhanced lubricating property is attributed to the two introduced carboxyl groups that enable DAIL molecules to adsorb more efficiently on sliding metal surfaces. Toxicity test data also show that DAIL lubricants possess lower toxicity than MAILs.
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INTERNATIONAL JOURNAL OF PHARMACEUTICS
·
2024
·
IF 5.3
Yang Li,Qin Yu,Yi Lu,Haisheng He,Jianping Qi,Zongguang Tai,Zhongjian Chen,Quangang Zhu,Wei Wu
Ionic liquids (ILs) show promises as chemical penetration enhancers (CPEs) for transdermal delivery of macromolecular drugs. However, their high viscosity and strong drug-IL affinity may limit drug diffusion and release from the drug-loaded IL (one-step strategy). Herein, a two-step strategy was used by applying choline-based ILs as pretreatment agents followed by insulin solution to improve penetration. Insulin remained stable in the ILs and are released slowly from the IL matrices. In vitro and in vivo studies showed that two-step treatment enhanced insulin penetration compared to one-step treatment, with choline citrate ([Ch][Ci]) and choline geranate ([Ch][Ge]) performing the best. In a diabetic rat model, two-step treatment with [Ch][Ge] reduced blood glucose levels to below 80% within 8 h, while one-step treatment only maintained for 12 h. Trans-epidermal water loss and molecular dynamics simulations suggested that variations in release rates and skin condition accounted for the differences between the two strategies. Physical characterization confirmed that ILs enhanced transdermal delivery of insulin by permeabilizing stratum corneum and opening tight junctions. Preliminary safety assessment indicated mild irritation by [Ch][Ge], whereas [Ch][Ci] showed good biocompatibility. It is concluded that ILs hold potential in enhancing transdermal delivery of insulin.
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高影响因子
FUEL
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2017
·
IF 4.601
Honghua Zhang,Ruixia Liu,Zhiqiang Yang,Feng Huo,Ruirui Zhang,Zihang Li,Suojiang Zhang,Yanji Wang
In this work, the alkylation of isobutane and butene, catalyzed by sulfuric acid in the presence of the fluoride–containing ionic liquids [Bmim][PF 6 ] and [Bmim][SbF 6 ], was investigated. The use of the binary mixture catalysts brought to a higher C 8 selectivity and longer catalyst lifetime, compared with the results obtained when working with sulfuric acid only. This was attributed to the formation of new species when [Bmim][PF 6 ] or [Bmim][SbF 6 ] are added to sulfuric acid. The acidolysis of [Bmim][PF 6 ] and [Bmim][SbF 6 ] was accompanied by the release of hydrogen fluoride (HF) and the decomposition of anions to [PF 6−x−2y (HSO 4 ) x (SO 4 ) y ] − and [SbF 6−x−2y (HSO 4 ) x (SO 4 ) y ] − , respectively. The presence of these new species after acidolysis was measured and confirmed by ion chromatography, 1 H–Nuclear Magnetic Resonance (NMR), 19 F–NMR and 31 P–NMR. The production of HF and the complexation of anions and carbenium ions both play an important role in stabilizing the carbenium ion and improving the catalytic performance.
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JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
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2012
·
IF 2.823
Xuanxuan Lu,Zhigang Luo,Shujuan Yu,Xiong Fu
Lipase-catalyzed synthesis of starch palmitate was investigated in ionic liquid mixtures consisting of 1-butyl-3-methyl-imidazolium acetic ([BMIm]Ac) and 1-butyl-3-methyl-imidazolium tetraflouroborate ([BMIm][BF4]). The effect of reaction parameters such as the amount of enzyme used, the reaction temperature, the mass ratio of [BMIm][BF4]/[BMIm]Ac, the molar ratio of methyl palmitate/anhydroglucose unit in starch, and the reaction time on the degree of substitution was studied. The formation of starch esters was confirmed by the presence of the carbonyl signal in the FT-IR and NMR spectra. Scanning electron microscopy and X-ray diffraction data showed that the morphology and crystallinity of starch esters were largely disrupted. Thermogravimetric analysis suggested thermal stability of starch palmitate decreased compared to native starch. Water contact angle measurements revealed that the hydrophobicity of starch esters was improved after modification. The successful lipase-catalyzed synthesis of starch palmitate in ionic liquids suggested that ionic liquids could be used as a potentially attractive green alternative to harmful organic solvents for synthesis of high fatty acid starch ester.
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高影响因子
FUEL
·
2012
·
IF 3.248
Cun Zhang,Xiaoyu Pan,Feng Wang,Xiaoqin Liu
The Brönsted acidic ionic liquids N-carboxymethylpyridine hydrosulphate ([CH 2 COOHPy][HSO 4 ]) and N-carboxyethylpyridine hydrosulphate ([(CH 2 ) 2 COOHPy][HSO 4 ]) were synthesized and used as the extractant and catalyst for the extraction–oxidation desulfurization of model oil. The structures of the ILs were confirmed by 1 H NMR and 13 C NMR. The density, viscosity and acid strength of the ILs were also investigated. The acid strength was in order of H 2 SO 4 (98%) > [CH 2 COOHPy][HSO 4 ] > [(CH 2 ) 2 COOHPy][HSO 4 ]. The [CH 2 COOHPy][HSO 4 ] showed better activity during the removal of dibenzothiophene (DBT) in n -octane by a combination of extraction and oxidation, and the sulfur removal reached 99.9% under the conditions of V model oil = 20 mL, V IL = 1.2 mL, T = 30 °C and H 2 O 2 /S molar ratio (O/S) = 6. In the same conditions, the removal of benzothiophene (BT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT) by using [CH 2 COOHPy][HSO 4 ] reached 82.5% and 89.1%, respectively. Ionic liquid [CH 2 COOHPy][HSO 4 ] can be recycled 9 times without a significant decrease in the sulfur removal.
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SEPARATION SCIENCE AND TECHNOLOGY
·
2012
·
IF 1.088
Xiaochun Chen,Ge Liu,Shan Yuan,Charles Asumana,Wenbo Wang,Guangren Yu
A new class of green solvents, known as ionic liquids (ILs), has recently been the subject of intensive research on the extractive desulfurization of fuel oils because of the limitation of the traditional hydrodesulfurization method in catalytically removing thiophenic sulfur compounds. In this work, four thiazolium-based ILs, that is, 3-butyl-4-methylthiazolium dicyanamide ([BMTH][DCA]), 3-butyl-4-methylthiazolium thiocyanate ([BMTH][SCN]), 3-butyl-4-methylthiazolium hexafluorophosphate ([BMTH][PF6]), and 3-butyl-4-methylthiazolium tetrafluoroborate ([BMTH][BF4]), are synthesized. The extractive capability of these ILs in removing thiophene (TS) and dibenzothiophene (DBT) from model fuel oils is investigated. [BMTH][DCA] and [BMTH][SCN] present better extractive desulfurization capability than [BMTH][BF4] and [BMTH][PF6], which may be ascribed to the additional π−π interaction between –C≡N (in [BMTH][DCA] and [BMTH][SCN]) and thiophenic ring (in TS and DBT); DBT in diesel fuel is more efficiently extracted than TS in gasoline. [BMTH][DCA] offers the best desulfurization results, where 64% and 45% sulfur removal are obtained for DBT and TS, respectively, at IL:oil mass ratio of 1:1, 25°C, 20 min. [BMTH][DCA] is thus selected to systematically investigate the effects of temperature, IL:oil mass ratio, initial sulfur content, multiple-extraction, and IL regeneration on desulfurization. The mutual solubility of [BMTH][DCA] with fuel oil is also determined. It is observed that the desulfurization capability is not too sensitive to temperature and initial sulfur content, which is desired in industrial application; the sulfur contents in gasoline and diesel fuel are reduced from 558 ppm to 20 ppm (after 5 cycles) and from 547 ppm to 8 ppm (after 4 cycles), respectively. This work may show a new option for deep desulfurization of fuel oils.
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TRIBOLOGY INTERNATIONAL
·
2024
·
IF 6.1
Ruisheng Guo,Zihan Liu,Xin Chen,Xiaoqiang Dou,Qian Ye,Xuqing Liu
Ti 3 C 2 T x MXene nanosheets are employed to graft ionic liquids via Michael addition or Schiff base reactions, with polydopamine acting as a bridging agent. This process creates a robust and synergistic tribological interface when the hybrids are used as lubricating additives in oil. The structural hybridization harnesses the high surface area and weak interlayer forces of MXenes, along with the thermal stability and film-forming capabilities of ionic liquids. The study reveals that lubricants fortified with these functionalized nanosheets exhibit a notable reduction in the average coefficient of friction from 0.188 to 0.112 and an 81.7% decrease in wear volume. These results highlight the untapped potential of structurally optimized, ionic liquid-functionalized MXenes as a transformative advancement in the field of tribology.
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危险品化学品经营许可证（带存储）