INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
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2014
·Vol. 15
·期 5
·8656-8666
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IF 2.339
Leqin He,Shenjun Qin,Tao Chang,Yuzhuang Sun,Jiquan Zhao
Quaternary ammonium geminal Brønsted acid ionic liquids (GBAILs) based on zwitterionic 1,2-bis[N-methyl-N-(3-sulfopropyl)-alkylammonium]ethane (where the carbon number of the alkyl chain is 4, 8, 10, 12, 14, 16, or 18) andp-toluenesulfonic acid monohydrate were synthesized. The catalytic ionic liquids were applied in three-component Mannich reactions with an aldehyde, ketone, and amine at 25 °C in water. The effects of the type and amount of catalyst and reaction time as well as the scope of the reaction were investigated. Results showed that GBAIL-C14has excellent catalytic activity and fair reusability. The catalytic procedure was simple, and the catalyst could be recycled seven times via a simple separation process without noticeable decreases in catalytic activity.Keywords:Mannich reaction;geminal ionic liquid;water;catalyst;emulsion
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CHEMICAL ENGINEERING JOURNAL
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2016
·
IF 5.31
Huawei Yang,Bin Jiang,Yongli Sun,Li Hao,Zhaohe Huang,Luhong Zhang
Novel Brønsted-Lewis acidic ionic liquids having a protonated N-octylcaprolactam-based cation and Cl/nZnCl 2 anion (n = 1, 2 and 3) were synthesized and investigated as catalysts in the oxidative desulfurization (ODS) of both model oil and real diesel fuel, with hydrogen peroxide (H 2 O 2 , 30 wt%) as oxidant. It is observed that the ODS performance increases significantly with the increase of ZnCl 2 proportion. Then detailed experiments for the ODS of model oil were carried out with [Hnoc]Cl/3ZnCl 2 to investigate the influence of some important factors, including reaction temperature, molar ratio of H 2 O 2 /S, ILs dosage, initial S-content and sulfide species. It is worth noting that, with the mass ratio of ILs/oil of only 1:20, satisfactory conversion rate can also be achieved for the removal of dibenzothiophene (DBT), and the ILs were used for six cycles without a noticeable decrease in activity. What is more important, the ILs can reduce the S-content of a real diesel from 559.7 ppm to 8.2 ppm with 98.5% sulfur removal rate and 96.3% diesel recovery through a one-step ODS process. Deduced from the GC-PFPD spectra, almost all the original S-compounds and their oxidized products were completely converted and extracted, respectively. The outstanding desulfurization efficiency can be attributed to the good phase transfer property of the ILs.
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ChemSusChem
·
2016
·Vol. 9
·期 17
·2351-2357
·
IF 7.116
Mingguang Pan,Ningning Cao,Wenjun Lin,Xiaoyan Luo,Kaihong Chen,Siying Che,Haoran Li,Congmin Wang
Graphical Dual-tuning method : Through the introduction of a large π-conjugated structure into the anion, a dual-tuning approach to improve CO 2 capture by anion-functionalized ionic liquids (ILs) results in high capacities of up to 0.96 ; and excellent reversibility. Quantum chemical calculations, spectroscopic investigations, and thermogravimetric analysis indicate that the increased capacity is a result of stronger dynamic covalent bonds. The strong chemisorption of CO 2 is always accompanied by a high absorption enthalpy, and traditional methods to reduce the absorption enthalpy lead to decreased CO 2 capacities. Through the introduction of a large π-conjugated structure into the anion, a dual-tuning approach for the improvement of CO 2 capture by anion-functionalized ionic liquids (ILs) resulted in a high capacity of up to 0.96 mol and excellent reversibility. The increased capacity and improved desorption were supported by quantum chemical calculations, spectroscopic investigations, and thermogravimetric analysis. The increased capacity may be a result of the strengthened dynamic covalent bonds in these π-electron-conjugated structures through anion aggregation upon the uptake of CO 2 , and the improved desorption originates from the charge dispersion of interaction sites through the large π-electron delocalization. These results provide important insights into effective strategies for CO 2 capture.
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APPLIED CLAY SCIENCE
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2017
·
IF 3.101
Wen Zhang,Meisheng Li,Jie Wang,Yijiang Zhao,Shouyong Zhou,Weihong Xing
New heterogeneous poly(ionic liquids) catalysts (PAL-PILs) were successfully prepared by grafting polymerization of acid ionic liquids (ILs) (1-butysulfonate-3-vinylimidazole hydrogen sulfate) onto nanofiber-like palygorskite (PAL) supports that had been, in advance, covalently modified by γ-methacryloxypropyl trimethoxy silane (OPAL). Using the ester yields and PILs grafting degrees as main indexes, the optimized immobilization conditions were that the mass ratio of OPAL to ILs monomer was 1:2, the immobilization temperature and time were 60 °C and 30 h, the initiator (2,2′-Azobis(2-methylpropionitrile) dosage was about 5 wt%, respectively. Then, the esterification between methanol and oleic acid was carried out to investigate the catalytic properties of PAL-PILs. For the homogeneous ILs catalyst, the yield of methyl oleate was about 85%. For the PAL-PILs, on which only about 41% of ILs used in homogeneous catalysis was immobilized, the yield could reach over 69% after reacting only 5 h at 75 °C at atmospheric pressure, when the molar ratio of methanol to oleic acid is adjusted to 12:1. More importantly, the yield of methyl oleate still maintained at about 22% after 6 recycling experiments. Moreover, the PAL-PILs catalysts exhibited efficient catalytic properties and could be recycled easily. These results offer great potential for the PAL-PILs in the biodiesel production for further research.
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Nature Communications
·
2024
·Vol. 15
·期 1
·1-12
·
IF 14.7
Zhang Jun,Zhou Xuan,Hu Qinyu,Zhou Kaijian,Zhang Yan,Dong Shengyi,Zhao Gai,Zhang Shiguo
The advancement of contemporary adhesives is often limited by the balancing act between cohesion and interfacial adhesion strength. This study explores an approach to overcome this trade-off by utilizing the spontaneous polymerization of a protic ionic liquid-based monomer obtained through the neutralization of 2-acrylamide-2-methyl propane sulfonic acid and hydroxylamine. The initiator-free polymerization process is carried out through a gradual increase in monomer concentration in aqueous solutions caused by solvent evaporation upon heating, which results in the in-situ formation of a tough and thin adhesive layer with a highly entangled polymeric network and an intimate interface contact between the adhesive and substrate. The abundance of internal and external non-covalent interactions also contributes to both cohesion and interfacial adhesion. Consequently, the produced protic poly(ionic liquid)s exhibit considerable adhesion strength on a variety of substrates. This method also allows for the creation of advanced adhesive composites with electrical conductivity or visualized sensing functionality by incorporating commercially available fillers into the ionic liquid adhesive. This study provides a strategy for creating high-performance ionic liquid-based adhesives and highlights the importance of in-situ polymerization for constructing adhesive composites.
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CHEMICAL ENGINEERING JOURNAL
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2024
·
IF 13.3
Haiyan Jiang,Li Xu,Kuilin Peng,Xiaoling Zhang,Shaojuan Zeng,Yangyang Guo,Lu Bai,Ming-Shui Yao,Xiangping Zhang
The capture and separation of ammonia (NH 3 ), a typical hydrogen-rich, carbon-free, but highly corrosive and pungent odorous gas, is significantly important for resource utilization, sustainable development and environment protection. The combination of functionalized ionic liquids (ILs) and porous supports to develop novel porous composites for NH 3 adsorption is an efficient way to achieve the above goals. In this work, dual functionalized IL (DFIL) simultaneously containing Lewis acidic sites and hydrogen bond sites supported porous Zr-MOF (Zr-bptc) with high stability and reversibility are developed for NH 3 adsorption. The DFIL confined in the nanopores not only provides high NH 3 affinity, but also reduces the pore size to form selective NH 3 diffusion pathways. Thus, the highest NH 3 adsorption capacity of 10.26 mmol/g at 1 bar and 25 °C was achieved by DFIL@Zr-bptc-50 wt%. Especially, the optimal composites showed high NH 3 /N 2 IAST of 3146.21 for NH 3 /N 2 (0.5/99.5, v/v) and 593.97 for NH 3 /N 2 (5/95, v/v), which is 269 % and 346 % higher than that of pristine Zr-bptc, respectively, indicating the composites have great potential for low-concentration NH 3 separation. Moreover, the mixed gas breakthrough experiments demonstrated that optimal DFIL@Zr-bptc also exhibits outstanding NH 3 /N 2 separation performance under simulative conditions including ammonia synthesis process and air purification. In addition, the DFIL@Zr-bptc composites show great structural stability and recyclability. This work provides a feasible way to design novel porous IL composites for NH 3 efficient removal and recovery.
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RSC Advances
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2017
·Vol. 7
·期 63
·39604-39610
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IF 3.108
Dan He,Ying Wu,Zhengping Liu,Tuo Zhao
A novel chemical approach to prepare the high performance polymer poly(phenylene sulfide sulfone) under mild conditions was presented based on 4,4-difluorodiphenylsulfone and sodium sulfide (Na2S) in i-pmim PF6 (IL)/MImBS (ZI) at atmospheric pressure and compared with conventional methods. The highest molecular weight (2.5 × 104) and yield (>99%) polymers were synthesized in IL/ZI in the presence of sodium carbonate and sodium hydroxide at 200 °C for 4 h. ZI can significantly improve solubility of the basic inorganic salt Na2S. And using ILs as solvents made removing toluene by purging with nitrogen much easier and the time was shortened significantly from 5–8 min to 1–2 min. In addition, the ILs can be recycled easily and still possess excellent performance.
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Catalysts
·
2024
·Vol. 14
·期 11
·796
·
IF 3.8
Shuang Tong,Tianqi Huang,Mengyue Chen,Zidan Zhu,Chao Wang,Hongping Li,Ming Zhang
A series of commercial silica-supported polyoxometalate ionic liquids ([Cnmim]3PMo12O40) with different substitutes in the imidazole ring were prepared via a facile ball milling method and employed as catalysts in the oxidative desulfurization of organosulfur compounds. The experimental results demonstrated that the active polyoxometalate center was successfully immobilized with a highly uniform dispersion on the silica. Without any organic solvent as the extractant, sulfur removal with the sample C16PMo/SiO2-BM reached 99.5% in 30 min under the optimal condition, which was ascribed to the high specific surface area and lipophilicity. In addition, the active site was verified by a free radical trapping experiment and an ESR spin capture experiment. In addition, the oxidative product was confirmed by GC-MS analysis.
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JOURNAL OF MOLECULAR STRUCTURE
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2024
·
IF 4
Fujie Liu,Tianqi Huang,Mengyue Chen,Jing He,Hongping Li,Chao Wang,Huaming Li,Ming Zhang
Due to the increased concern on the environmental issues, the desulfurization process in fuel is of great importance in the recent decades. Herein, a series of decavanadate-based poly (ionic liquids) with varied substituents were successfully prepared by a facile ion exchange method, which were employed in aerobic oxidative desulfurization of aromatic sulfides. The prepared samples can achieve deep desulfurization on different aromatic sulfides under optimal reaction conditions. Additionally, the experimental results indicated that the long carbon chains in the imidazole ring could hinder the ion exchange process between decavanadate and PILs due to steric hindrance effect, resulting in the poor desulfurization activity. Finally, a possible reaction mechanism was proposed according to the results of XPS, ESR and GC–MS analysis.
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SEPARATION AND PURIFICATION TECHNOLOGY
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2024
·
IF 8.1
Manman Zhang,Raphael Semiat,Xuezhong He
Design and synthesis of novel poly(ionic liquids) (PILs) containing amino groups hold great promise in CO 2 separation fields owing to the tunability of the cation and anion, as well as the high CO 2 affinity of the amino groups. Herein, two novel amino-functionalized PILs were designed for the preparation of composite membranes by casting the synthesized PIL-based solutions on the top of polysulfone ultrafiltration membranes to explore the effect of different chemical structures on the separation performances of the NH 2 -carrier-based membranes. Highly CO 2 -selective membranes with a CO 2 /N 2 selectivity of 173.5 were obtained by introducing the mobile carrier of 2-(1-piperazinyl) ethylamine sarcosine (PZEA-Sar) into the amino-functionalized PIL-based membranes, which provides the synergistic effect from both fixed-site and mobile carriers for promoting CO 2 -facilitated transport. Thus, the developed membranes may offer a high energy-efficiency process for industrial CO 2 capture.
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Lubricants
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2024
·Vol. 12
·期 5
·167
·
IF 3.1
Xiangyu Ge,Xiaodong Wu,Qiuyu Shi,Yanfei Liu,He Liang
This work studied the influence of the voltage parameters on the friction and superlubricity performances of LiPF6-based ionic liquids (ILs). The results show that the voltage direction and magnitude greatly affected the friction performances of ILs and that macroscale superlubricity can be achieved with a stimulation of −0.1 V. The surface analysis and experiment results indicate that the voltage magnitude influences the coefficient of friction (COF) by determining the types of substances in the tribochemical film formed on the ball, while the voltage direction influences the COF by affecting the adsorption behavior of Li(PEG)+ions on the ball. At −0.1 V, the cation group Li(PEG)+adsorption film and FeOOH-containing tribochemical film contribute to friction reduction. The formation of FexOywithin the tribochemical film results in an increase in friction at −0.8 V. The limited adsorption of Li(PEG)+ions and the formation of FexOycontribute to the elevated COF at +0.1 V. This work proves that the friction performances of LiPF6-based ILs could be affected by voltage parameters. A lubrication model was proposed hoping to provide a basic understanding of the lubrication mechanisms of ILs in the electric environment.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2024
·
IF 7.7
Yunchang Fan,Qiang Zhou,Sheli Zhang,Yanhe Nie
Thiosulfate has been considered as a more environmentally-friendly alternative to cyanide salts for the extraction of gold from gold ores and the development of affordable, green and efficient adsorbents for the isolation of gold-thiosulfate complex (Au(S 2 O 3 ) 2 3− ) from the leaching solution remains a significant challenge. To address this issue, chitosan, a natural macromolecule , was selected as a carrier and chemically modified with ionic liquids . The ionic liquids modified chitosan showed greater adsorption capacity towards Au(S 2 O 3 ) 2 3− compared with pristine chitosan. The adsorption of Au(S 2 O 3 ) 2 3− on ionic liquid modified chitosan followed Freundlich isotherm and pseudo-second order kinetic models, involving an anion-exchange mechanism with liquid film diffusion as the rate-limiting step. The chitosan modified with butylimidazolium-based ionic liquid had an adsorption capacity of 5.0 mg g −1 for gold (10 mg L −1 of gold, pH 6, 2 g L −1 of adsorbent dosage), outperforming other reported adsorbents. The ionic liquid modified chitosan showed a high adsorption efficiency of up to 96.7 % for Au(S 2 O 3 ) 2 3− in an actual thiosulfate leaching solution with a desorption efficiency of 98.4 %, suggesting that the ionic liquid modified chitosan has the potential to be a eco-friendly, biocompatible and effective adsorbent for the recovery of Au(S 2 O 3 ) 2 3− .
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