JOURNAL OF MOLECULAR LIQUIDS
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2022
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IF 6.633
Shuang Li,Shenyi Jiang,Pingbo Zhang,Pingping Jiang,Yan Leng
Trimethylolpropane acrylate (TMPTA) is becoming an important organic chemistry intermediate, but it’s synthesis through the acid-catalyzed esterification of trimethylolpropane and acrylic acid is a challenge due to the poor activity and catalyst separation problems. In this work, a series of 1,3-propanesultone (PS)-functionalized imidazole ionic liquids (ILs) are prepared and evaluated as the acid catalysts for this reaction, including the catalytic performance comparison, optimization of reaction conditions, and the catalytic reusability. The obtained H 2 SO 4 -based IL ([IMPSH]HSO 4 ) caused a phase-separation catalytic process (reacted as a homogeneous catalyst, but precipitated at the end of reaction like a heterogeneous catalyst), presenting the best trimethylolpropane conversion (100%) and TMPTA selectivity (86.4%). Such catalytic performance is even better than that of homogeneous H 2 SO 4 . Moreover, the catalyst can be steadily reused at least four times without obvious change in activity and its structure. The highly efficient and environmentally benign performance of [IMPSH]HSO 4 -catalyzed esterification of trimethylolpropane and acrylic acid make it possible to achieve industrial applications.
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ACS Sustainable Chemistry & Engineering
·
2022
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IF 9.224
Jinhui Chen,Qinqin Xu,Feng He,Wang Yue,Gang Hu,Jianyun Gan,Haibo Xie
Economically competitive and sustainable dissolution pretreatment technology is in high demand due to the remarkable achievement in the pretreatment of lignocellulose using ionic liquids (ILs) for enhanced enzymatic hydrolysis. Herein, levulinic acid (Lev), a well-known bio-based platform chemical derived from carbohydrates, in conjunction with a series of organic superbases, was used as a raw chemical to prepare a new class of protic ILs (PILs). The findings indicated that the obtained PILs exhibited a good solubility of up to 10 wt % toward corn stover-based lignocellulose at 140 °C in 40 mins, based on which a facile and efficient dissolution pretreatment technology was developed for enhanced enzymatic hydrolysis of corn stover. The facile dissolution and regeneration of corn stover resulted in significant changes in the composition and physical–chemical structures. These changes led to significantly enhanced enzymatic hydrolysis behavior of the pretreated sample with total reducing sugar and glucose yields of 0.8 and 0.49 g/g within 48 h under optimal conditions, respectively. The Kamlet–Taft solvent parameters of the PILs were systematically evaluated, and the interaction between the lignocellulose and PILs was studied by 13C NMR, indicating that the satisfactory performance of PILs was benefited from the higher ß parameter value and the stronger interactions, particularly the existence of the extra hydrogen-bond interaction from the potential keto–enol tautomerism of the ketone groups in levulinate anions. The compositional and physicochemical changes in the lignocellulose were systematically evaluated to achieve an in-depth understanding of the dissolution activation mechanism using various characterization techniques. The findings also showed that 44.3% of lignin could be fractionated during the facile dissolution and regeneration process, together with a transformation of the crystalline structure of cellulose I to cellulose II and of the packed morphology to a porous one. The structure of the fractionated lignin was also characterized for a better understanding of the fractionation process. The study demonstrated a new sustainable dissolution pretreatment technology for enhanced enzymatic hydrolysis, which can provide significant insights into the design of new solvents for biomass dissolution and processing.
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GREEN CHEMISTRY
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2022
·Vol. 24
·期 21
·8292-8301
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IF 11.034
Cong Luo,Jiayi Wang,Houfang Lu,Kejing Wu,Yingying Liu,Yingming Zhu,Binshen Wang,Bin Liang
An ideal strategy for the management of greenhouse gas carbon dioxide (CO2) and surplus industrial product-glycerol (Gly) is to convert them into the valuable glycerol carbonate (GC). However, conventional conversion processes rely on high CO2 pressure and reaction temperature. In this work, a series of easily prepared protic ionic liquids (ILs) were studied for the one-pot synthesis of GC using CO2, Gly, and styrene oxide (SO). A 94% yield of GC was obtained with the catalysis of 1,8-diazabicyclo[5.4.0]undec-7-enenium iodide (HDBUI) under atmospheric pressure at 45 °C. Experimental results and density functional theory (DFT) calculations suggest that the high catalytic activity of HDBUI is attributed to the strong nucleophilicity and substrate activation afforded by the synergistic effect of the protic HDBU+ cation and I− anion. In addition, high GC yields were also obtained when simulated flue gas and crude Gly were used as substrates.
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SEPARATION AND PURIFICATION TECHNOLOGY
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2022
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IF 9.136
Hui Yu,Xinyu Li,Chuanqi Geng,Xiaojia Wu,Fan Zhang,Shichao Tian,Zhiyong Zhou,Zhongqi Ren
The separation of aromatic and aliphatic hydrocarbons is one of the most challenging and energy-consuming operations in the petrochemical industry. In this study, a number of N -methylpyrrolidone (NMP)-based coordinated ionic liquids (ILs) with various metal salts were prepared and their separation performances were investigated. Among these coordinated ILs, NMP-0.1Fe(NO 3 ) 3 ·9H 2 O showed high selectivity and was used to separate toluene from n -heptane or cyclohexane. Fourier-transform infrared spectroscopy was used to verify that the synthesis of NMP-0.1Fe(NO 3 ) 3 ·9H 2 O was achieved. The toluene distribution coefficient and selectivity were 0.20 and greater than 70, respectively, for a 10 mol% toluene/ n -heptane system, and 0.20 and 23.5, respectively, for a 20 mol% toluene/cyclohexane system. Changing the extraction temperature had little effect on the separation performance. The effects of the solvent dosage, initial concentrations of system components, and regeneration times were also investigated. Experimental liquid–liquid equilibrium data for the studied ternary systems were correlated with the non-random two-liquid model. The results show that NMP-0.1Fe(NO 3 ) 3 ·9H 2 O has potential industrial applications.
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JOURNAL OF SEPARATION SCIENCE
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2022
·Vol. 45
·期 18
·3604-3613
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IF 3.614
Xiaofei Ma,Bohua Chen,Liangliang Cai
Taking advantage of chiral ionic liquids, this study deals with the improvement of the enantioseparation performance of a traditional chiral selector (maltodextrin) in capillary electrophoresis. Herein, two polyhydroxy compound-based chiral ionic liquids, namely tetramethylammonium-D-gluconic acid and tetramethylammonium-shikimic acid were designed and utilized as additives for chiral separation for the first time. The synergistic systems provided much better enantioseparations of twelve model drugs compared to the single maltodextrin system. These model analytes contained analgesics, antidepressants, antiallergic drugs, antifungal drugs, antihypertensive drugs, and antiparkinsonian drugs. After optimizing the separation conditions, the chiral recognition mechanism was probed by means of ultraviolet spectroscopy, nuclear magnetic resonance, and molecular modeling. The results of spectroscopic and computational analyses were in good consistency with enantioseparation outcomes. Finally, the proposed method was successfully used for the determination of the enantiomeric purity of duloxetine hydrochloride.
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JOURNAL OF APPLIED POLYMER SCIENCE
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2021
·Vol. 139
·期 14
·51903
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IF 3.125
Liurong Huang,Shuang Ding,Tian Chen,Ruike Wu,Xinyu Wang,Shifang Jia
This paper explores the structural and functional properties of collagen from tilapia scales pretreated by heat-assisted ionic liquids (ILs). Results show that the solubility of collagen was significantly influenced by the type and concentration of ILs. With the increase of IL concentration, a remarkable decrease in solubility of collagen was seen. Fluorescence spectra show that heat and IL pretreatments induced the exposure of chromophores. Changes in sodium dodecyl sulfate–polyacrylamide gel electrophoresis indicated that subunits of collagen regenerated from most of the IL solvent systems were not destroyed. The functional properties of regenerated collagen were evaluated by gel strength, viscosity, water-binding capacity, and emulsifying capacity. Results show that all heat-assisted ILs pretreatments improved the gel strength and viscosity, and the highest gel strength and viscosity were both obtained in the collagen pretreated by heat-assisted [EMIM]Cl. Heat-assisted [BMIM]BF 4 pretreatment exhibited the lowest water-binding capacity. Heat-assisted [BDMIM]Cl pretreatment indicated superior effect on improving emulsifying capacity than other pretreatments due to its ability to break most of the hydrogen bonds in collagen molecules, resulting in the formation of new re-aggregates with higher solubility and more hydrophobic groups.
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Reaction Kinetics Mechanisms and Catalysis
·
2021
·Vol. 134
·期 2
·823-835
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IF 2.081
Wang Ying,He Runfa,Wang Cong,Li Gang
A kind of heterogeneous catalyst MCM-41-S-ImBr was prepared by grafting 1-vinyl-3-ethylimidazolium bromide ([VEIM]Br) on the surface of MCM-41. The catalyst was characterized by X-ray diffraction patterns, Fourier transform infrared spectroscopy and element analysis as well as scanning electron microscopy. It showed that [VEIM]Br was successfully grafted on MCM-41 and the catalyst possessed an average particle size of 1.4 µm with intact mesoporous structure. Moreover, the catalyst exhibited high catalytic activity in the cycloaddition reaction of CO 2 with epichlorohydrin without co-catalyst. The conversion of epichlorohydrin was 98.5% and the selectivity of cyclic carbonate was 98.3% at 130 °C under 1.6 MPa for 6 h. Reaction kinetic study indicated that the pseudo-first order rate constant was 0.223 ± 0.001 h −1 . It is proved that MCM-41-S-ImBr could be used at least 4 times without obvious decrease in catalytic performance. A possible reaction mechanism was also proposed: the quaternary imidazolium ion cooperatively worked with the bromide ion to catalyze the reaction. Graphical Abstract
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SENSORS AND ACTUATORS B-CHEMICAL
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2021
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IF 7.46
Wenyan Yin,Khaled Tawfik Alali,Milin Zhang,Jingyuan Liu,Dalei Song,Qi Liu,Jing Yu,Rongrong Chen,Hongsen Zhang,Jun Wang
Ionic liquids are widely employed as electrolytes for electrochemical oxygen sensing due to their excellent physical and chemical properties. Recently, combining inorganic electrochemically active materials with ionic liquids are becomes intensively interesting to improve oxygen sensor performance. In this paper, two imidazolyl-based ionic liquids 1-ethyl-2,3-dimethylimidazole bis((trifluoromethyl)sulfonyl)imide [Emmim][TFSI] and 1-butyl-2,3-dimethylimidazole bis((trifluoromethyl)sulfonyl)imide [Bmmim][TFSI] with three saturated alkyl substituents on the aromatic ring were prepared by a traditional two-step method. Under the electrochemical test, both ionic liquids exhibit a certain responsibility to different concentrations of oxygen. Subsequently, α-Fe 2 O 3 /rGO was prepared by hydrothermal method and then mixed with the ionic liquids to prepare a composite ionic liquid electrolyte for detecting a wide range of oxygen concentrations. The response performance of prepared composite electrolyte toward the oxygen is improved, which exhibits a sensitivity of 0.1041 μA/[%O 2 ] to gradually changed oxygen concentration and a linear correlation (R 2 ) of 0.9997 between oxygen reduction peak currents. Hence, the results show that the pure ionic liquid has a certain ability to detect oxygen, while adding α-Fe 2 O 3 /rGO compounds further improve responsibility, stability and sensitivity of composite electrolyte to oxygen.
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APPLIED SURFACE SCIENCE
·
2021
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IF 6.707
Pengyan Li,Li Liu,Weijia An,Huan Wang,Wenquan Cui
Photocatalytic CO 2 reduction is a potential way to address simultaneously environmental pollution and energy shortage. However, the difficulties of CO 2 activation and C C coupling lead to quite low conversion efficiency of CO 2 to C2 products. In this study, we constructed Cu 2 O/g-C 3 N 4 heterojunction for photocatalytic CO 2 reduction to ethanol by coupling thermal field and ionic liquids (ILs). The ethanol rate reached 0.71 mmol·g −1 ·h −1 over Cu 2 O/g-C 3 N 4 under photothermalcatalysis, which is 1.89 times that of photocatalysis and 7.05 times that of thermal catalysis. The temperature enhanced thermal motion of the radical, which promotes the formation of ethanol through the ·CH 3 dimerization. The 1-aminopropyl-3-methylimidazolium bromide ILs shows superior CO 2 reduction performance with a high current density (21.3 mA·cm −2 ) than KHCO 3 electrolyte (12.8 mA·cm −2 ). The overpotential is reduced by 0.34 V, which accelerates CO 2 reduction by reducing polarization. It is found that the ILs played a key role in suppressing H 2 O reduction and increasing ethanol yield in this photothermalcatalytic strategy.
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TRIBOLOGY INTERNATIONAL
·
2021
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IF 4.872
Lili Zhu,Jun Dong,Qunfeng Zeng,Mianran Chao,Kuiliang Gong,Weimin Li,Xiaobo Wang
In this paper, a group of quaternary ammonium amino acid ionic liquids (QAAA ILs) prepared by coupling the tetrabutylammonium cation with fourteen types of natural amino acids as base lubricant were investigated for steel/steel, steel/copper and steel/aluminum contacts at ambient temperature and elevated temperature. The corrosion resistance and tribological ability of various QAAA ILs was determined. The influences of various anionic structures on kinematic viscosity , corrosivity , thermal stability and tribological properties of the ILs were discussed in detailed. The copper strip corrosion test results showed that the present ILs have been proved to be almost non-corrosive. Tribological behaviors results displayed that the present ILs exhibit extremely eminent friction reduction and antiwear properties. Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) analysis revealed that a protective lubricating film is formed on the surface of contact mainly through a polarity induced physical adsorption when QAAA ILs are selected as neat lubricants, which plays a key role in reducing friction and wear between the moving mechanical interface.
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JOURNAL OF HAZARDOUS MATERIALS
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2020
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IF 9.038
Kaihang Zhang,David Kujawski,Chris Spurrell,Dong Wang,Junchen Yan,John C. Crittenden
Polyfluoroalkyl Substances (PFAS) such as perfluorooctanoic acid (PFOA) are resistant to biodegradation leading to adverse health outcomes. Therefore, PFAS removal from drinking water is paramount. Liquid-liquid extraction processes can remove them from water; however, the hydrophobic and oleophobic properties of PFOA lead to the low extraction efficiency and severe emulsification , especially for the ppm-levels concentration of PFOA. Therefore, we introduced ionic liquid (IL) methyltrioctylammonium bis(trifluoromethylsulfonyl)imide ([A336][NTf 2 ]) as extractant into octanol. We found that using hexadecyl trimethyl ammonium bromide (CTAB) as an extractant caused severe and stable emulsion. In comparison, [A336][NTf 2 ] could suppress the emulsification with high extraction efficiency. The extraction performance of PFOA was examined as a function of various parameters. The results showed that the extraction efficiency was strongly dependent on the concentration of IL and aqueous pH. Further research revealed the extraction mechanisms at the molecular-level, and density functional theory (DFT) and molecular dynamic (MD) simulation agreed with the trends in the experiment. We determined that the extraction efficiency of PFOA from water could be up to 88.21 wt% for the optimized condition, indicating that the extraction system of [A336][NTf 2 ] + octanol was efficient for separating PFOA from the diluted aqueous solution.
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CHEMICAL ENGINEERING JOURNAL
·
2020
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IF 10.652
Jifang Fu,Yufeng Xu,Linna Dong,Liya Chen,Qi Lu,Mengmeng Li,Xingfa Zeng,Sanwei Dai,Guorong Chen,Liyi Shi
In this work, we have successfully synthesized a series of multiclaw-shaped octasilsesquioxanes functionalized ionic liquids and then used it developing novel hybrid solid polymer electrolytes (SPEs) with high room temperature ionic conductivity. The effect of POSS ionic liquids with varying chain in imidazole on the microstructures, thermal stabilities and electrochemical properties of the obtained SPEs were studied. The scanning electron microscope images of SPEs membranes confirm that the POSS ionic liquids were uniformly distributed in the polymer matrix. The solid polymer electrolytes exhibit high electrochemical stabilities with a wide electrochemical window up to 5.0 V, a lithium-ion transference number ( t Li+ ) of 0.32 and high ionic conductivity of 3.06 × 10 −4 S cm −1 at 22 °C. Moreover, the Li/LiFePO 4 cells containing POSS-ILs-SPEs exhibit excellent cycling performance and rate capability, the initial discharge capacity is 150.7 mAh g −1 and initial coulombic efficiency is 100% at a rate of 0.1C. The capacity of the cells can reach to 130 mAh g −1 and the coulombic efficiency is 99.9% after 90 cycles.
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危险品化学品经营许可证（带存储）