INDUSTRIAL CROPS AND PRODUCTS
·
2015
·
IF 2.837
Peng Zhang,Shi-Jia Dong,Hui-Hui Ma,Bi-Xian Zhang,Yu-Fei Wang,Xiao-Mei Hu
Lignocellulosic biomass is increasingly being promoted as an environmentally and economically sustainable fuel. However, the complex structure of lignocellulose makes it difficult to be fractionated, which limits its conversion into valuable products. In this work, a series of functional acidic ionic liquids (ILs) with a simple synthetic procedure were prepared. Fractionation of corn stover into cellulose, hemicellulose and lignin was successfully performed in ultrasound-assisted ILs at a low reaction temperature of 70 °C for 3 h followed by alkaline extraction. IL-isolated lignin, alkaline lignin, hemicellulose and cellulose were obtained in good yields and their chemical properties were analyzed by FTIR. Significantly, a good yield of IL-isolated lignin was obtained, which accounted for 60.48% of the original lignin. The IL-isolated lignin was S-G-H type indicating by 13 C NMR and 13 C– 1 H correlation 2D NMR (HSQC) analysis. Enzymatic hydrolysis of cellulose was performed successfully. A high yield of 97.77% reducing sugar was achieved. Glucose and cellobiose were measured by HPLC analysis, which accounted for 92.55% of cellulose conversion. Both of the hydrogen bond capability and the acidity of ILs contributed to achieve the effective fractionation. These ILs have a great potential for the preparation of biofuel.
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ACS Sustainable Chemistry & Engineering
·
2018
·
IF 6.14
Congkai Ma,Fei Xu,Weiguo Cheng,Xin Tan,Qian Su,Suojiang Zhang
Synthesis of bioderived high-molecular-weight polycarbonates over metal-free catalysts is of great importance but also challenging. In this work, a series of 1-butyl-3-methylimidazolium (Bmim) ionic liquids (ILs) were prepared as catalysts for a melt polycondensation reaction of isosorbide and diphenyl carbonate. By modifying the structures of ILs’ anions, the number-average molecular weight (Mn) of poly(isosorbide carbonate) (PIC) was effectively tailored. In the presence of a trace amount (0.05 mol % based on isosorbide) of bifunctional [Bmim][CH3CHOHCOO], the synthesized PIC possessed high Mn of 61,700 g/mol and a glass transition temperature of 174 °C, both the highest so far to the best of our knowledge. Besides, it was found that the anions with stronger electronegativity and hydrogen bond formation ability were more efficient for the formation of PIC with higher Mn. To modify the flexibility of PIC, poly(aliphatic diol-co-isosorbide carbonate)s with Mn ranging from 34,000 to 75,700 g/mol were also formulated by incorporating with various aliphatic diols. Additionally, based on the experimental results and nuclear magnetic resonance spectroscopy, a possible mechanism of cooperative nucleophilic–electrophilic activation through hydrogen bond formation and electrostatic interactions by the ILs catalyst was proposed.
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Science of Advanced Materials
·
2016
·Vol. 8
·期 8
·1673-1677
·
IF 1.812
Shi Yuedan,Liu Chunguang,Xu Linran,Nan Wang,Guan Xiaohui
We studied the physical properties of aqueous solution of four acid functional room temperation ionic liquids based on imidazolium: 1-(3-sulfonic group) propyl-3-methylimidazole hydrosulfate ([PSIM][HSO4]), 1-(3sulfonic group) propyl-3-methylimidazole dihydrogen phosphate
([PSIM][H2PO4]), bis-(3-methyl-1-imidazole) butylidene double hydrosulfate ([DBIM] [HSO4]2, bis-(3-methyl-1-imidazole) butylidene double dihydricphosphate ([DBIM][H2PO4]2). The measurements of acidity, refractive
index, viscosity and electrical conductance were made. The molar conductivity was calculated. The physical properties of aqueous solutions changes with the concentration of aqueous solution, the cation and the anion.
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FUEL
·
2015
·
IF 3.52
Dan Zheng,Wenshuai Zhu,Suhang Xun,Miaomiao Zhou,Ming Zhang,Wei Jiang,Yuejiao Qin,Huaming Li
A kind of highly active TiO 2 was prepared and applied in the extractive and catalytic oxidative desulfurization (ECODS) system. The catalyst was synthesized through a simple method and characterized by X-ray powder diffraction (XRD), Raman, Fourier transform infrared (FT-IR) and X-ray photoelectron spectroscopy (XPS). Various of reaction conditions were investigated on the removal of dibenzothiophene (DBT), and a sulfur removal of 99.1% was obtained under 40 °C in 90 min. In addition, electron spin resonance (ESR) spectroscopy and gas chromatography–mass spectrometer (GC–MS) measurements were employed to investigate the reaction mechanism. It was proved that superoxide radical ( O 2 − ) was the active oxygen species and DBTO 2 was the only oxidation product of DBT in the ECODS system. The recycling experiments indicated that sulfur removal could still reach 95.5% after 12 times.
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高影响因子
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY
·
2022
·Vol. 58
·期 6
·837-843
·
IF 0.862
Gu Zhengyu,Xue Feng,Yu Jiale,Ju Shengui
Abstract N -Aryl anthranilic acid drugs have been synthesized by a simple, environmentally friendly, low-cost, and high-yielding modified Ullmann coupling reaction protocol using potassium 2-bromobenzoate, substituted anilines, and copper acetate in tetrabutylphosphonium chloride ([TBP]Cl) ionic liquid. The optimal conditions have been found and applied to the synthesis of N -aryl anthranilic acid drugs at 170°C. Mass spectrometry, X-ray crystallography, and proton nuclear magnetic resonance were used to describe the structure of the products. Copper(I) complex catalyst was used as a starting catalyst for the Ullmann reaction because of the good fluidity and homogeneity in [TBP]Cl ionic liquid. Meclofenamic, mefenamic, clofenamic, and flufenamic acids were synthesized efficiently using the proposed general procedure. The distinct advantages of the described protocol are operational simplicity, cleaner reaction, high selectivity, excellent yield, rapid conversion, easy preparation, and the use of a low-cost catalyst.
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JOURNAL OF MOLECULAR LIQUIDS
·
2021
·
IF 6.165
Shengbin Shi,Yuanfeng Wu,Mengting Zhang,Zongqi Zhang,Olayinka Oderinde,Lijing Gao,Guomin Xiao
The conversion of cellulose to levulinic acid (LA) and other platform chemicals is a promising route to solve the energy crisis. For this purpose, a series of new SO 3 H-functionalized ionic liquids (ILs), containing different halogen-anions were synthesized and applied for catalytic conversion of cellulose to LA. The structure, thermal stability, and acidity of SO 3 H-functionalized ILs were characterized by Nuclear magnetic resonance (NMR) spectra, Fourier-transform infrared (FT-IR), High resolution mass spectrometry (HRMS), thermogravimetric analysis (TGA), and Hammet acidity method. The results revealed that as the size of halogen anions increased, the Hammett acidity gradually increased from SO 3 H-functionalized ILs containing fluorine- to chlorine- and then to bromine-anions. When SO 3 H-functionalized ILs were used as a catalyst for the production of LA from cellulose, the yield of LA gradually increased as the size of halogen-anions increased from fluorine- to chlorine- and then to bromine-anions. Among the SO 3 H-functionalized ILs, 1,1-bis(3-(4-sulfobutyl)imidazolium-1-yl)butylene bromine ([BSim]Br) exhibited the best catalytic activity with 76.5% yield of LA in cellulose/[BSim]Br/H 2 O ( m / m / m = 1:9:8) reaction system at 180 °C for 20 min, which was the highest yield compared to previous literature reports using ILs as catalyst. Besides, the [BSim]Br was easily recovered and showed high catalytic activity after five cycles. The efficient catalyst, [BSim]Br is then proposed to have a great potential for mass production of LA from biomass.
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RSC Advances
·
2016
·Vol. 6
·期 85
·81913-81923
·
IF 3.289
Jianbin Qin,Guangcheng Zhang,Zhonglei Ma,Jiantong Li,Lisheng Zhou,Xuetao Shi
Shear thickening fluids (STFs) are energy dissipative materials and affected significantly by the properties of the dispersing media. Most of the dispersing media are polymeric or oligomeric fluids, and few studies have made ionic liquids (ILs) as the dispersing media. Since the properties of ILs are strongly dependent on its' ionic structures, the shear thickening behavior of STFs composed of ILs must be influenced by the ionic structures. The rheology and viscoelasticity of STFs of hydrophilic silica nanoparticles in ILs with different ionic structures were investigated systematically. The experimental results demonstrated that the dispersions in hydrophilic ILs displayed shear thickening behavior, while dispersions prepared by hydrophobic ones appeared as a colloidal gel and displayed shear thinning. With changing the length of the alkyl chain substituent on the organic cation, the shear thickening behavior was transformed. Shear thickening behavior was enhanced for the introduction of hydroxyl on the organic cation. Ionic structures influence the interactions between silica nanoparticles and ILs through the hydrogen bonds, and the shear thickening behavior may be induced by the formation of nanoparticle aggregation. The dynamic stabbing resistance, quasi-static tensile strength and conductivity of Kevlar fabric composites treated by STFs composed of ILs were enhanced observably, and the electromagnetic shielding property was improved to a certain degree.
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Analytical Methods
·
2012
·Vol. 4
·期 4
·1012-1018
·
IF 1.547
Xiaojie Liu,Yuzhi Wang,Jinhuan Kong,Chan Nie,Xiao Lin
Eight types of ionic liquid (IL) were synthesized in this paper, and ionic liquids-based microwave-assisted extraction (ILs-MAE) technique was used to extract quercetin from the Chinese herbal medicine Toona sinensis. Several significant operating parameters were optimized by a series of single factor experiments and orthogonal design L9 (34) experiments in this work. Compared with liquid-based maceration extraction (ILs-ME), liquid-based heat extraction (ILs-HE) and liquids-based ultrasound-assisted extraction (ILs-UAE), the optimized approach of ILs-MAE technique cost the shortest time but afforded the highest extraction amount. Moreover, reversed phase high performance liquid chromatography (RP-HPLC) with ultraviolet detection (UV-DAD) was employed for the analysis. The results show that the amount of quercetin extracted by [Bmim]Br was 182.78 mg g−1 with RSD 1.02%. The developed approach is linear between concentrations from 15.20 mg L−1 to 213.2 mg L−1 of quercetin and the regression coefficient (R) was 0.9992. The recoveries of quercetin extracted by these four methods were 95.07%–105.8% with RSDs lower than 3%. Furthermore, the change of the microstructure and chemical structure of the sample before and after different extraction procedures were researched, respectively. Because of the remarkable dissolving capacity of ILs aqueous solution and the obvious destruction on sample surface microstructures during ILs-MAE process, ILs-MAE technique got the highest extracted amount. With the help of LC-MS, we can further confirm that Toona sinensis do contain the active ingredient of quercetin and ILs had no interference of quercetin.
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ChemCatChem
·
2025
·
IF 3.9
Yannan Han,Jilei Xu,Beizhan Li,Qingda An,Zuoyi Xiao,Jiahui Huang
Graphical In this study, we developed a new strategy for the synthesis of long-chain dicarboxylic acid ester precursors via the aldol condensation of 2,5-diformylfuran (DFF) and methyl levulinate (MLA) in the presence of protic ionic liquids. The reaction mechanism was further investigated using nuclear magnetic resonance (NMR) and Fourier transform infrared spectroscopy (FTIR). In this study, a series of long-chain dicarboxylic acid ester precursors were synthesized via aldol condensation reactions catalyzed by protic ionic liquids (PILs). When 2,5-diformylfuran (DFF) and methyl levulinate (MLA) were employed as substrates, the yield of long-chain dicarboxylic acid ester precursors reached 91.0% in the presence of pyrrolidine lactate. This preparation process eliminated the need for additional acids and bases, thereby minimizing the generation of waste salts, which was a common issue in base-catalyzed systems and biosynthesis methods. Nuclear magnetic resonance (NMR) characterization revealed that a strong interaction between the hydroxyl group of the catalyst and the carbonyl group of MLA facilitated the activation of the substrate for the aldol condensation reaction. Notably, the yield of dicarboxylic acid ester precursors remained stable even after five catalytic cycles, demonstrating the excellent reusability of the catalyst. Furthermore, pyrrolidine lactate exhibited broad applicability in both aldol condensation and Knoevenagel condensation reactions. This work presented a novel and sustainable strategy for the synthesis of long-chain dicarboxylic acid ester precursors.
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高影响因子
CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2019
·
IF 1.911
Xiaomei Ling,Yiwei Xie,Xiaocheng Lin,Ling Li,Ting Qiu
To prepare polymer supported ionic liquids (PSILs) as effective catalysts for esterification, the free radical suspension copolymerization of vinylbenzyl chloride (VBC, monomer), styrene (St, monomer) and divinylbenzene (DVB, crosslinker) with the addition of n -heptane (porogen) was carried out for the fabrication of the porous polymer (PVD) microsphere as support, followed by the immobilization of sulfonic acid-functionalized ionic liquids by the successive treatment of benzimidazole (BIm), 1,3-propane sultone and sulfuric acid (H 2 SO 4 ) or trifluoromethanesulfonic acid (CF 3 SO 3 H). The effects of the compositions of DVB and n -heptane on the internal structure of the polymer supports were investigated, and it was found that the support with 40 wt% DVB and 60 wt% n -heptane (with relative to the monomer) could endow the final PSILs with the relatively optimal catalytic performance. The preliminary experiment in the batch reactor indicated that PSILs herein exhibited higher catalytic activities than commercial Amberlyst 46 resin for the esterification of propanoic acid (PROAc) with n -propanol (PROOH). Consequently, the optimal PSILs catalyst, PVD-[Bim-SO 3 H]HSO 4 , was selected for further study in the batch reactive distillation column because of low cost and its ease of preparation. The yield of propyl ropionate (PROPRO) could reach up to 97.78% at the optimized conditions of PROOH/PROAc molar ratio (2:1) and catalyst dosage (2.0 wt%). The investigation of the reaction kinetic manifested that the calculated results of second order pseudo-homogeneous kinetic model were in good agreement with experimental values. The pre-exponential factor and activation energy were 4.12 × 10 7 L·mol −1 ·min −1 and 60.57 kJ·mol −1 , respectively. It is worth noting that the PSILs catalyst could be simply recovered and reused with relatively satisfactory decrease in the catalytic activity, which made it an environmental friendly and promising catalyst in the industrial application.
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SEPARATION AND PURIFICATION TECHNOLOGY
·
2019
·
IF 5.107
Yunchang Fan,Dongxu Cai,Sheli Zhang,Huiying Wang,Kaigang Guo,Lei Zhang,Lei Yang
The removal of nitrogen compounds by liquid-liquid extraction using ionic liquids (ILs) as extraction solvents has been limited by the lack of easy-to-prepare, low cost and highly efficient ILs. To overcome this limitation, the present work synthesized protic ILs (PILs) via acid-base reaction and investigated their extraction ability for nitrogen compounds (quinoline, indole and carbazole) from model fuel ( n -dodecane). Experimental results suggested that the PIL, triethylammonium p -toluenesulfonate (TEA-TSA), exhibited higher extraction ability for indole and carbazole as compared to the 1-butyl-3-methylimidazolium ([C 4 mim] + ) based ILs due to the stronger π-π interaction between TEA-TSA and nitrogen compounds. Among a number of ILs, TEA-TSA containing a slight excess of p -toluenesulfonic acid (2%, molar percent) was particularly promising as extractant because of its excellent extraction performance for the basic and neutral nitrogen compounds. Furthermore, the suggested PIL could be easily regenerated and reused via a back extraction process. The results showed that extractive denitrogenation using PILs as extractants was a potential technique to produce clean fuel considering their stronger extraction ability, lower-cost and easy-to-prepare characteristics.
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CHEMICAL PHYSICS
·
2024
·
IF 2
Xinyuan Zhang,Xinyao Tang,Zhenhai Zhong,Xinyi Ge,Qingguo Zhang
The hydroxylammonium ionic liquids (ILs) falling within the category of protic ionic liquids (PILs) have garnered attention from researchers, owing to their outstanding solubility properties. A one-step method was employed to synthesize a series of ethanolamine ILs. The thermodynamic properties of the ILs, including surface tension, density, and electrical conductivity, were measured across varying temperatures. Essential parameters such as thermal expansion coefficient, molecular volume, surface entropy, and surface energy were estimated using empirical equations. In order to elucidate the intermolecular interactions within the ethanolamine carboxylate ILs, the sigma profiles of ILs were determined using COSMO-RS. It was observed that the ethanolamine cation has a strong potential as a H-bond donor, while the carboxylate anion demonstrates significant capability as a hydrogen bond acceptor. By DFT calculations, it was observed that the N H in the ethanolamine cation can form H-bonds with the oxygen atom in the carboxylate anion.
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危险品化学品经营许可证（带存储）