CANADIAN JOURNAL OF CHEMICAL ENGINEERING
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2021
·Vol. 100
·期 12
·3717-3726
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IF 2.007
Piao Cao,Lin Zheng,Weizhen Sun,Ling Zhao
Four typical Brønsted acidic ionic liquids (BILs) and concentrated sulphuric acid (H 2 SO 4 ) were used to catalyze the transesterification of fish oil with ethanol to produce fatty acid ethyl ester (FAEE) in this work. The experimental results show that the imidazole BILs lead to fewer side reactions and higher product quality than H 2 SO 4 . Molecular dynamics (MD) simulations indicate that [PSMim][HSO 4 ] molecules can be enriched at the interface and enhance the contact of eicosapentaenoic acid triglyceride (EPATG, a typical component of fish oil) and ethanol. And ester groups of EPATG tend to expose more to ethanol in the BILs system, which facilitates the occurrence of transesterification. However, H 2 SO 4 has no positive effect on the distribution of the two reactants. For the transesterification, the interfacial property affects the catalytic activity a lot, instead of catalyst acidity. Also, the reaction rate is accelerated, obviously, by ultrasound-led liquid–liquid phase emulsification.
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EUROPEAN POLYMER JOURNAL
·
2021
·
IF 4.598
Tianlin Wang,Yue Zheng,Guangren Yu,Xiaochun Chen
The catalytic effect of nanoparticles was significantly affected by its size and surface property. In this work, a series of ionic liquids were synthesized and used as surfactant to modify CoFe 2 O 4 MNP. XRD, FT-IR, TEM and VSM were performed to characterize modified CoFe 2 O 4 . The modified CoFe 2 O 4 MNP with average size of 7 nm was obtained and it was so well dispersed in ethylene glycol that ethylene glycol based magnetic fluid was obtained. Modified CoFe 2 O 4 MNP was used as catalyst for glycolysis of PET and showed excellent catalytic effect. The influence of ionic liquids surfactant and experimental factors on glycolysis were investigated. Under optimal condition, PET (5 g), catalyst (CoFe2O4/C10-OAC, 0.1 g) and EG (25 g) at 195 °C for 2.5 h, the PET conversion was 100% and BHET yield was 95.4%. More importantly, this catalyst can be collected by external magnetic field and its catalytic effect did not obviously decrease after it was reused for ten times. This work provided a new type of highly efficient catalyst of glycolysis of PET.
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JOURNAL OF MEMBRANE SCIENCE
·
2021
·
IF 8.742
Bingbing Yang,Lu Bai,Tingting Li,Liyuan Deng,Lei Liu,Shaojuan Zeng,Jiuli Han,Xiangping Zhang
Efficient separation and recovery of ammonia (NH 3 ) is essential for environmental protection and resource utilization. In this work, hybrid membranes for NH 3 separation through multiple-site interaction were developed by combining the unique features of ionic liquids (ILs) and a midblock-sulfonated block copolymer . The functionalized ILs ([2-Mim][NTf 2 ] and [Im][NTf 2 ]) with ammonia interaction sites were incorporated into the Nexar™ matrix, which greatly improves the affinity for NH 3 over nitrogen (N 2 ) and hydrogen (H 2 ). Benefited from the self-assembly of the block copolymer, the hybrid membranes primarily exhibit lamellar morphology. More continuous ionic domains with well-distributed ILs were formed in the hybrid membranes, contributing to forming interconnected channels for enhanced gas transport. In this case, addition of the ILs into the Nexar matrix significantly enhances NH 3 separation performance. Nexar/[Im][NTf 2 ]-25 membrane achieves the highest NH 3 permeability of 3565 Barrer and a maximum NH 3 /N 2 and NH 3 /H 2 ideal selectivity of 1865 and 364, respectively. The significantly enhanced NH 3 permeation compared with the neat Nexar membrane indicates the positive role of ILs in the hybrid membranes.
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MACROMOLECULES
·
2021
·
IF 5.985
Xiaoliang Yu,Zhengyi Xia,Tengda Zhao,Xiaoyan Yuan,Lixia Ren
Organic magnets are promising in quantum computers, spintronic devices, and information storages for their excellent processing and smart design abilities, resulting from the organic part. However, the organic part shields the magnetic centers to weaken the magnetic interaction. In this work, π–π stacking planar pyrene groups are introduced into cations of a magnetic ionic liquid (NBPBI[FeCl4]) and poly(ionic liquid) (PNBPBI[FeCl4]) with FeCl4– as the anions. By introducing pyrene groups, the shortest distance between neighboring magnetic units is within 4 Å. The ferromagnetic interactions in NBPBI[FeCl4] and PNBPBI[FeCl4] are enhanced by the π–π stacking pyrene groups. Moreover, the corresponding organic magnets are soft ferromagnets, as phase transition from paramagnetism to ferromagnetism is observed from zero field cooling and field cooling tests at the low temperature. This is a new strategy for designing a ferromagnetic organic magnet.
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ENERGY & FUELS
·
2021
·
IF 3.605
Congsu Niu,Lianyuan Ji,Yao Chen,Shuai Ma,Yiwei Zhang,Xiaomin Liu,Hui Yang
Sodium–metal chloride batteries are usually operated at a relatively high temperature (270–350 °C) to achieve adequate electrochemical performance. Such a high operating temperature may cause several issues and limit their widespread applications. Lowering the operating temperature may alleviate these issues, which can be achieved by reducing the ohmic resistance of a Na−β″-Al2O3 solid electrolyte (BASE) and incorporating a low-melting-point catholyte. Herein, a planar sodium–copper chloride battery is evaluated at intermediate temperatures (from 100 to 175 °C) with a thin BASE disk (500 μm) and a room-temperature ionic liquid (RTIL). The RTILs at various concentrations (0.1–0.75 mol L–1) are prepared by dissolving different amounts of sodium bis(trifluoromethanesulfon)imide (NaTFSI) into 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMIm][TFSI]) and used as the catholyte. The effect of NaTFSI addition in [EMIm][TFSI] on the physical properties of the catholyte is examined. With 0.5 mol L–1 NaTFSI in [EMIm][TFSI] ionic liquid to assemble the Na/CuCl2 battery, the fabricated cell delivers a capacity up to 146.5 mAh g–1 when cycled at 175 °C with the current density of 2 mA cm–2 and retains 94.5% capacity after 20 cycles. Moreover, the battery can run steadily at 130 °C and show a reversible capacity of 79.2 mAh g–1 when the operation temperature is set as low as 100 °C. To the best of our knowledge, these are the lowest operation temperatures reported thus far for sodium–metal-chloride-based cells.
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CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Ping Li,Jia Chen,Shaokun Tang
Covalent organic frameworks (COFs) hold great potential for proton-conducting materials due to the intrinsic pore channels and high surface areas. However, their limited functional groups and poor film-forming properties remain significant challenge. Silk nanofibrils (SNFs) have good mechanical property and abundant functional groups, which can be exfoliated from natural bombyx mori silks. Herein, we demonstrate a novel strategy of utilizing the flexibility of SNFs to assemble conductive COFs into a stable membrane form. Ionic liquids (ILs)-impregnated sulfonic acid-based COF (IL-COF-SO 3 H) is prepared and then is combined with SNF to fabricate IL-impregnated COF/SNF composite membrane. The uniformly distributed ILs inside COF-SO 3 H increase the number of proton hopping sites. Meanwhile, the –SO 3 H groups can form strong interactions with imidazole-type ILs and immobilize ILs within the channels, endowing COF-SO 3 H pores low-barrier proton transfer pathways. Additionally, the hydrogen-bonding interactions between IL-COF-SO 3 H and SNFs enable interfacial binding and structure stability, as well as facilitate proton transfer. Thus, the resultant IL-COF-SO 3 H@SNF composite membrane simultaneously obtains enhanced conductivity (224 mS cm −1 at 90 °C and 100% RH) and mechanical performance (tensile strength of 28.6 MPa). This study provides novel insight into fabrication of stable COF-based membrane for high-performance conduction materials.
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CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2020
·
IF 2.627
Qiu Zhao,Gang Wang,Fuxia Liao,Yifan Sha,Fei Xu,Chunshan Li,Zengxi Li,Yijun Cao
An ionic liquid (IL) catalyzed solvent-free process was developed for the direct synthesis of chalcone and its derivatives by using substituted acetophenones and benzaldehydes via aldol reaction under mild conditions. A series of acidic and basic ILs were selected and screened. The influences of cations and reaction conditions on product yield and selectivity were systematically investigated. The [Bmim]OH was identified as the optimal IL, with the highest yield and selectivity reaching up to 96.7% and 100%, respectively. A reaction mechanism-based kinetic model was established and regressed with experimental data, revealing the β -Hydroxylketone dehydrolysis with activation barrier of 37.8 kJ·mol −1 was observed as the rate-controlling step.
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NANOTECHNOLOGY
·
2020
·Vol. 31
·期 50
·505402
·
IF 3.551
Hao Ying,Chenyun Zhang,Tingting Chen,Xiaoning Zhao,Zhonghao Li,Jingcheng Hao
The electrochemical hydrogen evolution reaction (HER) is a promising strategy for production of hydrogen; however, it is still restricted by appropriate efficient and low-cost electrocatalysts. Herein, for the first time, the n-octylammonium hypophosphite, a kind of protic ionic liquid (IL), was used as a new phosphorus source for the manufacture of nickel metaphosphate (Ni2P4O12) electrocatalysts. In contrast to traditional multi-step fabrication processes, the n-octylammonium hypophosphite acted as both reactant and solvent to synthesize Ni2P4O12 by a one-step calcination approach. The obtained Ni2P4O12 as an alkaline HER catalyst required a low overpotential of 116 mV at −10 mA cm−2 and a small Tafel slope of 97 mV dec−1, comparable to the majority of reported Ni-based materials and other phosphate catalysts. Furthermore, this catalyst exhibited robust stability with no distinct attenuation of current density after a long-term durability test in 1 M KOH. Therefore, this task-specific IL strategy with a simple reaction system, reducing the occurrence of side reactions, provided a new perspective on design of high-efficiency metaphosphate electrocatalysts.
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JOURNAL OF CHROMATOGRAPHIC SCIENCE
·
2021
·Vol. 59
·期 4
·388-395
·
IF 1.618
Ma Xiaofei,Li Jingtang,Li Xiaoqi,Feng Zijie,Yang Xuan,Liu Jie,Du Yingxiang
Nowadays, ionic liquids (ILs) functionalized cyclodextrins (CDs) have drawn increasing attention in chiral separation. Herein, a novel β-CD derivative functionalized by L-histidinium IL, mono-6-deoxy-6-L-histidinium-β-cyclodextrin chloride (L-HMCDCl), was synthesized for the first time and utilized for enantioseparation of nefopam and chlorphenamine in capillary electrophoresis. The L-HMCDCl exhibited superior enantioselectivity compared with native β-CD. The effect of some key parameters such as chiral selector concentration, buffer pH and applied voltage on the enantioseparation was investigated in detail. In the interest of the chiral discrimination mechanism and the enhanced enantioselectivity of L-HMCDCl, molecular modeling with AutoDock was employed to study the interaction, which was in good agreement with experimental results.
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Chemical Engineering and Processing-Process Intensification
·
2020
·
IF 3.731
Jingwei Yan,Yu Zhao,Keying Li,Huimin Zhang,Liwei Fan,Zexiang Lu
A novel approach was developed for producing biodiesel by acid ionic liquid catalyzed esterification of oleic acid and methanol under ultrasonic-microwave combined intensification. Four kinds of acid ionic liquids were synthesized as suitable catalysts. Some key parameters affecting oleic acid conversion were investigated using single factor experiments. Moreover, the production process was optimized via response surface methodology. The results indicated that the ionic liquid 1-(4-sulfobutyl)-3-methylmidazolium hydrosulfate exhibits good catalytic performance because of its double acid sites. The ultrasonic-microwave combined assistance can intensify the process to significantly shorten the reaction time from about 180 min to 15 min, thereby affording good industrial application potential. The specified regression model is accurate, reliable, and adequate for simulating actual production; the oleic acid conversion was 97.85 %, which is close to that achieved with conventional methods.
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Polymers
·
2020
·Vol. 12
·期 2
·297
·
IF 3.426
Haiyan Du,Zemin Wu,Yuyu Xu,Shaoze Liu,Huimin Yang
In this work, solid-state polymer supercapacitor (SSC) was assembled using poly(3,4-ethylenedioxythiophene/carbon paper (PEDOT/CP) as an electrode and ionic liquid (1-butyl-3-methylimidazole tetrafluoroborate)/polyvinyl alcohol/sulfuric acid (IL/PVA/H2SO4) as a gel polymer electrolyte (GPE). The GPE was treated through freezing–thawing (F/T) cycles to improve the electrochemical properties of PEDOT SSC. Cyclic voltammetry (CV), galvanostatic charge–discharge measurements (GCD) and electrochemical impedance spectroscopy (EIS) techniques and conductivity were carried out to study the electrochemical performance. The results showed that the SSC based on ionic liquid GPE (SSC-IL/PVA/H2SO4) has a higher specific capacitance (with the value of 86.81 F/g at 1 mA/cm2) than the SSC-PVA/H2SO4.The number of F/T cycles has a great effect on the electrochemical performance of the device. The energy density of the SSC treated with 3 F/T cycles was significantly improved, reaching 176.90 Wh/kg. Compared with the traditional electrolytes, IL GPE has the advantages of high ionic conductivity, less volatility, non-flammability and wider potential window. Moreover, the IL GPE has excellent elastic recovery and self-healing performance, leading to its great potential applications in flexible or smart energy storage equipment.Keywords:poly(3,4-ethylenedioxythiophene);1-butyl-3-methylimidazolium tetrafluoroborate;gel polymer electrolyte;solid state supercapacitor
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Journal of Materials Chemistry C
·
2020
·Vol. 8
·期 32
·11119-11127
·
IF 7.059
Zijian Gao,Lingshu Kong,Rining Jin,Xin Liu,Wei Hu,Guanghui Gao
With the prosperity of flexible energy storage and wearable strain sensing, the ion conductive hydrogel attracts booming attention as electrolyte materials of flexible supercapacitors and flexible strain sensors due to the distinguishing soft and wet feature. Herein, a self-healing hydrogel with mechanical, adhesive and conductive properties has been designed and prepared by introducing polydopamine nanoparticles and water-soluble ionic liquids into hydrophobic association polyacrylamide. The resultant hydrogel samples could be employed as an electrolyte and wearable strain sensor, simultaneously. As hydrogel electrolytes, the resultant supercapacitor possesses a capacitance of 0.37 F g−1 and capacitance retention of 75.42% after 8000 cyclic charge–discharge tests. Furthermore, the supercapacitor exhibits a capacitance of 0.365 F g−1 after self-healing, which is 98.65% compared to the original data. As flexible strain sensors, the hydrogels could detect tiny and large-scale human movements in accordance with resistive signals and a gauge factor of 0.841. It could be anticipated that the self-healing hydrogels could be prospective flexible materials for a new generation of flexible sensors and supercapacitors over a wide temperature range.
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