ACS Sustainable Chemistry & Engineering
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2017
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IF 5.951
Yaju Chen,Rongchang Luo,Qihang Xu,Jun Jiang,Xiantai Zhou,Hongbing Ji
Multifunctionalization of organic polymers for acting synergistically on substrate is of wide interest in the field of modern catalysis, but it is still a significant challenge. Herein, two novel bifunctional polymers were first designed and synthesized by combining ionic liquids (ILs) with zinc(II) porphyrin through simple and reversible Schiff base reactions. The fabricated polymers with flexible structures and nitrogen-rich environments presented high affinity toward CO2 molecules at ambient conditions. Owing to the cooperative nature of intercalated ILs and Lewis acidic metal sites, these materials could serve as efficient heterogeneous catalysts for the insertion of CO2 into epoxides to produce cyclic carbonates. As expected, these polymers exhibited good catalytic performance, robust constancy, excellent recyclability, and good substrate expansibility for this reaction in the absence of cocatalyst under mild or even ambient conditions. Notably, the selected catalyst SYSU-Zn@IL2 could directly convert diluted CO2 (15% CO2 in N2) into cyclic carbonate at 80 °C and 3.0 MPa, further offering the great application potential for recycling real-world carbon resource.
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SEPARATION AND PURIFICATION TECHNOLOGY
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2017
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IF 3.359
Yuehua Chen,Huiyong Wang,Yuanchao Pei,Jianji Wang
It is always difficult to separate scandium from yttrium and lanthanides due to their similar physicochemical properties. In this work, a selective separation strategy for Sc (III) from yttrium and lanthanides in aqueous solution was developed by using ionic liquids 1-alkylcarboxylic acid-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([(CH 2 ) n COOHmin][Tf 2 N]) (n = 3, 5, 7) as extractants and 1-alkyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([C n mim][Tf 2 N]) (n = 4, 6, 8, 10) ionic liquids as diluents. The extraction parameters such as phase valume ratio, equilibrium time, pH value of the aqueous phase, alkyl chain length of the extractants and diluents, and system temperature were investigated systematically. It was shown that the extraction efficiency of Sc (III) increased with the increase of aqueous phase pH value, and was as high as 99.5% at pH 4.2. Sc (III) could be extracted selectively from yttrium and lanthanides by simple tuning of pH value of the aqueous phase, and the separation factor was 10 3 . After the extraction, stripping of Sc (III) from the ionic liquids was attempted by using dilute aqueous HNO 3 . In addition, an ion exchange mechanism of the proton of extractants and the cation of the diluents was proposed from a series of control experiments. Since both the proton of the extractants and cation of the diluents participated in the extraction process, amount of the ionic liquids transferred to water phase can be greatly reduced compared with the cation exchange based metal extraction using only ionic liquid extractants.
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CHINESE JOURNAL OF CATALYSIS
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2017
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IF 2.813
Cong Zhao,Shengxin Chen,Ruirui Zhang,Zihang Li,Ruixia Liu,Baozeng Ren,Suojiang Zhang
A series of acetate ionic liquids were synthesized using a typical two-step method. The ionic liquids were used as environmentally benign catalysts in the production of propylene glycol ethers from propylene oxide and alcohols under mild conditions. The basic strengths of the ionic liquids were evaluated by determination of their Hammett functions, obtained using ultraviolet-visible spectroscopy, and the relationship between their catalytic activities and basicities was established. The catalytic efficiencies of the ionic liquids were higher than that of the traditional basic catalyst NaOH. This can be attributed to the involvement of a novel reaction mechanism when these ionic liquids are used. A possible electrophilic-nucleophilic dual activation mechanism was proposed and confirmed using electrospray ionization quadrupole time-of-flight mass spectrometry . In addition, the effects of significant reaction parameters such as concentration of catalyst, molar ratio of alcohol to propylene oxide, reaction temperature, and steric hindrance of the alcohol were investigated in detail.
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SusMat
·
2024
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IF 18.7
Shi-Peng Chen,Dan-Yang Zhao,Jin-Long Zhu,Jing Wang,Gan-Ji Zhong,Hua-Dong Huang,Zhong-Ming Li
The manipulation of hydrogen bonding within protic ionic liquids is conducive to conquering the robust hydrogen bonding interactions in cellulose for its effective dissolution, but it is a great challenge to establish the delicate balance of hydrogen bonding network between solvent and cellulose. Herein, we proposed the concept of “hydrogen bond producers” for urea molecules in 1,1,3,3-tetramethylguanidinium methoxyacetate acid ([TMGH][MAA]) to enhance the dissolution of cellulose. The optimization of physicochemical properties for [TMGH][MAA] solvent as a function of urea concentration revealed a remarkable increase in cellulose solubility from 13% to 17% (w/w) by adding only 0.25 wt% urea, highlighting the efficiency of [TMGH][MAA] as a powerful solvent for the dissolution of cellulose. The experimental and simulation results verified that the significant improvement on dissolution of cellulose was attributed to the hydrogen bonding interaction of urea molecules with ion pairs and part of free ions, reducing the interference with the active ions bonded to cellulose. Furthermore, the considerable enhancement on comprehensive properties of regenerated cellulose films demonstrated the effectiveness of [TMGH][MAA]/urea solvent. The concept of “hydrogen bond producers” presented here opens a new avenue for significantly enhancing the dissolution of natural cellulose, promoting the sustainable development in large-scale processing of cellulose.
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高影响因子
MOLECULES
·
2024
·Vol. 29
·期 10
·2381
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IF 4.2
Liran Ji,Wei Zhang,Yifei Zhang,Binbin Nian,Yi Hu
The development of immobilized enzymes with high activity and stability is critical. Metal–organic frameworks (MOFs) have attracted much academic and industrial interest in the field of enzyme immobilization due to their unique properties. In this study, the amino-functionalized ionic liquid (NIL)-modified metal–organic framework (UiO-66-NH2) was prepared to immobilizeCandida rugosalipase (CRL), using dialdehyde starch (DAS) as the cross-linker. The results of the Fourier transform infrared (FT-IR) spectra, X-ray powder diffraction (XRD), and scanning electronic microscopy (SEM) confirmed that the NIL was successfully grafted to UiO-66-NH2. The CRL immobilized on NIL-modified UiO-66-NH2(UiO-66-NH2-NIL-DAS@CRL) exhibited satisfactory activity recovery (79.33%), stability, reusability, and excellent organic solvent tolerance. The research results indicated that ionic liquid-modified UiO-66-NH2had practical potential for application in enzyme immobilization.
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PubMed
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
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2024
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IF 5.6
Xin Zhao,He-Fei Wan,Shao-Fei Sun,Ce Gao,Shuang Zhang,Run-Cang Sun
Lignin commonly has a low antioxidant activity despite acting as a natural antioxidant . Most of the reported chemical reagents for enhancing lignin phenolic hydroxyl content contain halogen or metal elements, which is expensive, toxic environment and non-recyclable. Here, a cost-effective and eco-friendly technique for increasing the phenolic group content and antioxidant capability of lignin was described. Protic ionic liquids , an effective demethylating reagent with advantages of zero halogen, low cost and recyclability was applied for lignin demethylation . Quantitative 1 H NMR and semi-quantitative 2D HSQC NMR analyses revealed the conversion of methoxy groups to phenolic groups. Typically, ethanolamine acetate was able to efficiently demethylate the methoxy of raw lignin at a rate as high as 44.73 %, which increased the amount of phenolic group in RL to 215.69 %. Besides, the recovery rate of [HOAc]-based protic ionic liquids and lignin was both over 90 %. The IC 50 value of organic lignin (OL) on scavenging of 2,2-Diphenyl-1-picrylhydrazyl was decreased to 0.15 mg/mL, which was better than natural or synthesized antioxidative chemicals.
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JOURNAL OF MEMBRANE SCIENCE
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2024
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IF 8.4
Yanting Tang,Qingnan Wang,Xiaohe Tian,Chenlu Liu,Keming Zhang,Xiaoting Feng,Rui Zhang,Yueyangchao Yu,Shaofei Wang
Covalent organic frameworks (COFs), characterized by their well-organized porous structure, exhibit promising prospects for carbon capture. Nevertheless, their weak film-forming property and relatively large pore sizes constrain their utilization as gas separation membranes. This study introduced a facile approach to fabricating COF membranes tailored for CO 2 separations. By introducing an extra monomer, trimesoyl chloride (TMC), together with COF monomers, a thin and defect-free layer of COF-polyamide was synthesized by interfacial polymerization process. The amide structure embedded into the COFs layers was expected to mend the defects, strengthen the binding forces, and improve the stability of the COFs layers. To further enhance the performance, imidazolium ionic liquid (IL) was adopted to modify the COF-polyamide layer. The introduction of TMC rendered the COF-polyamide layer more negatively charged, facilitating stronger binding to the positively charged cations in the IL. This modification with IL effectively reduced the pore size of the COFs and increased the affinity for CO 2 . The resultant COF composite membranes exhibited a high CO 2 permeance of 125.9 GPU and CO 2 /N 2 selectivity up to 35.0, accompanied by robust long-term stability. Our method paves a new way for the fabrication and application of interfacial polymerized COF membranes for gas separation applications.
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CHEMICAL ENGINEERING JOURNAL
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2024
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IF 13.3
Haoran Ma,Wei Zhao,Ping Li,Ailing Huang
Alkylbenzene (LAB) is an important benzene derivative that can be used as a raw material for high-performance anionic surfactants such as alkylbenzene sulfonates (LAS) to meet the new requirements for surfactants in many fields. LAB can be synthesized through Friedel-Crafts reaction in the presence of acidic catalysts as alkylating agents, which is commonly used in the production of fine chemicals. In this work, a novel and efficient continuous flow micro reaction system was introduced to enhance the production of long-chain alkylbenzene catalyzed by [(CH 3 ) 3 NH][Al 2 Cl 7 ] ionic liquid. The optimal conditions were investigated for the synthesis of long-chain alkylbenzenes with the 1-tetradecene and mixing α-alkenes of C 14 -C 16 from Fischer-Tropsch process. The results showed that the yield of benzene alkylation can achieve 99 % under the optimal process conditions which the reaction tube length was 2000 mm, the reaction temperature was 30 ℃, the catalyst dosage was 0.30 mL/min and the molar ratio of aluminum chloride to trimethylamine hydrochloride was 2:1. In addition, α-alkenes with C 14 -C 16 lead to deactivation of the ionic liquids catalyst easier because of transfer of AlCl 3 from the ionic liquid to the organic phase compared to the pure 1-tetradecene as an alkylating agent. Continuous synthesis of the long-chain alkylbenzenes catalyzed by ionic liquids can achieve in the microchannel reaction system by controlling the flow patterns.
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SEPARATION AND PURIFICATION TECHNOLOGY
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2024
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IF 8.1
Dongbo Wang,Jingting Sang,Mingyang Wang,Dawei Luo,Dandan Han,Bowen Zhang,Jingtao Wang,Junbo Gong
Stereoselective recognition using “tailor-made” chiral ionic liquids (CILs) is an effective approach to obtaining enantiopure compounds through crystallization resolution. In this study, CILs were used as additives to stereoselectively inhibit the nucleation and growth of unwanted enantiomers via a conformational matching mechanism. Interestingly, a cosolvency phenomenon was found in the threonine-CILs-ethanol solvent system. Based on this, an enhanced stereoselective crystallization resolution strategy that combines ultrasound and cosolvency was proposed. The goal of this strategy was to improve the crystallization yield and enantiomeric purity. The results showed that the crystallization resolution yield of the cosolvency system was 33.43%, higher than that of the pure water system (13.56%). More importantly, the introduction of ultrasonic enhancement further increased the crystallization resolution yield to 39.45%. This work will facilitate the exploration of the unlimited potential of utilizing the cosolvency phenomenon and ultrasonic enhancement for crystallization resolution.
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JOURNAL OF MOLECULAR LIQUIDS
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2012
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IF 1.58
Xiaoqing Wang,Li Yu,Jingjing Jiao,Huina Zhang,Rui Wang,Hui Chen
A series of novel COOH-functionalized imidazolium-based surface active ionic liquids (SAILs), N-alkyl-N′-carboxymethyl imidazolium bromide ([N-C n , N′-CO 2 H-Im]Br, n = 10, 12, 14), was synthesized. Their aggregation behavior in aqueous solution was investigated by surface tension and steady-state fluorescence measurements. From surface tension data, a group of micellization parameters was obtained. Compared with 1-alkyl-3-methylimidazolium bromide ([C n mim]Br) bearing the same hydrocarbon chain, [N-C n , N′-CO 2 H-Im]Br exhibits considerably lower critical micelle concentration (cmc) and surface tension at cmc (γ cmc ), higher adsorption efficiency ( pC 20 ) and effectiveness of surface tension reduction ( π cmc ), indicating the incorporation of carboxyl group favors micelle formation. The average aggregation number (N agg ) values of [N-C n , N′-CO 2 H-Im]Br, determined by fluorescence quenching method, are slightly different from those of [C n mim]Br. The effect of temperature on the aggregation behavior of [N-C 12 , N′-CO 2 H-Im]Br was also studied. It is found that there exists a minimum cmc at nearly 38 °C, which is higher than that of [C 12 mim]Br.
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JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2011
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IF 2.089
Qing-Guo Zhang,Si-Si Sun,Slawomir Pitula,Qing-Shan Liu,Urs Welz-Biermann,Jia-Jun Zhang
A series of solutions composed of air- and water-stable hydrophobic ionic liquids (ILs) [Etpy][Tf2N], [Bupy][Tf2N], [Pepy][Tf2N], [EtM4py][Tf2N], and [BuM4py][Tf2N] were prepared. The electrical conductivity of the solutions was investigated at T = 298.15 K, respectively. Then the electrical conductivity of solutions of [Bupy][Tf2N] and [Hepy][Tf2N] in acetonitrile/propylene carbonate were investigated at temperature range from (283.15 to 313.15) K. The correlation of concentration and electrical conductivity was fitted according to the empirical Casteel–Amis (CA) equation. The maximum electrical conductivity was extrapolated by the fitted result. The influence of the successive methylene (−CH2−) group and the organic solvent to the electrical conductivity was discussed. The temperature dependence of the electrical conductivity of the solutions, ILs [Bupy][Tf2N] and [Hepy][Tf2N] in acetonitrile/propylene carbonate, was fitted by the empirical Vogel–Fulcher–Tamman (VFT) equation at a volume ratio of 50 %.
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FUEL
·
2024
·
IF 6.7
Yuqing Chang,Yujiao Wu,Ruoke Liu,Yuan Jiang,Zhijun Zhou,Tianlin Wang,Xiaochun Chen
In order to achieve low cost, and reduce energy consumption during regeneration, a novel ionic liquid phase change absorbent composed of tetraethylenepentamine [TEPA] imidazole [Im] and diethylene glycol dimethyl ether (DGME) and water was designed for CO 2 capture applications. The absorbent [TEPAH][Im]+DM+H 2 O can achieves a CO 2 absorption capacity of 2.08 mol CO 2 /mol ILs, the rich phase volume accounts for 15.6 vol%, and the mass fraction of CO 2 is 99 %, this greatly reduces the regenerative volume of the absorption system, showing the potential of energy saving and emission reduction. After five absorption–desorption cycles, the regeneration efficiency of the system remained above 96 %. The CO 2 capture mechanism was analyzed using both 13 C NMR spectroscopy and density functional theory (DFT) calculations to elucidate its underlying processes. The cation [TEPAH] + and the anion [Im] - each undergo a reaction with CO 2 to produce carbamate, followed by hydrolysis of carbon dioxide to yield carbonate. The absorption system’s phase transition behavior primarily arises from variations in CO 2 product solubility across solvents. Moreover, the ionic liquid facilitated the conversion of CO 2 into quinazoline-2,4 (1H, 3H)-dione with a remarkable yield of 98 %. Even after five cycles, the ILs maintained substantial catalytic activity.
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危险品化学品经营许可证（带存储）