SEPARATION AND PURIFICATION TECHNOLOGY
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2024
·
IF 8.1
Yuanyuan Cui,Jianmin Sun
The direct oxidative carboxylation of olefins and CO 2 to synthesize cyclic carbonates involves a tandem process of epoxidation and CO 2 cycloaddition reactions. However, designing a multifunctional catalyst for this reaction remains challenging. Herein, a composite catalyst ImBr@UiO-66-Br(Co) was synthesized by post-metallization of Co 2+ and subsequent functionalization with an imidazole ionic liquid (IL), which was used effectively for this reaction. The effects of temperature, CO 2 pressure, catalyst dosage, and reaction time on the direct oxidative carboxylation of olefins to cyclic carbonates were investigated. The results showed that ImBr@UiO-66-Br(Co) exhibited optimal performance in the solvent-free reaction system with styrene (3 mmol), tert -butyl hydroperoxide (6 mmol), and tetrabutylammonium bromide (TBAB, 50 mg) at 80 ℃ under 1 MPa CO 2 for 24 h, achieving a styrene conversion of 90.3 % and styrene carbonate selectivity of 80.7 %. The excellent catalytic activity of ImBr@UiO-66-Br(Co) was attributed to the synergistic interactions of the Lewis acidity Zr 4+ sites, the strong nucleophilicity provided by Br - , the weak base sites from tertiary amine and quaternary ammonium groups in imidazole IL, and the redox-active Co 2+ sites. Additionally, the catalyst was easy to separate and maintained stable activity and selectivity over at least five cycles. Finally, the potential catalytic mechanism for the direct oxidative carboxylation of olefins to cyclic carbonates was proposed.
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TRIBOLOGY LETTERS
·
2025
·Vol. 73
·期 2
·1-16
·
IF 3.3
Fan Junjing,Shen Yan,Liu Ye,Qu Jinghao,Liu Jie,Yu Baihong,Xu Jiujun
Aminoguanidine-based ionic liquid which can reduce the friction coefficient and wear depth has been developed as lubricant additives for the piston ring and cylinder liner within 80–240 °C. The friction coefficient and wear depth reduction become more significant as the temperature increases. At 240 °C, the coefficient of friction decreases by 23.1% compared to fully formulated mineral based engine oil (FFO). The wear depth of the piston ring and cylinder liner decreases by 9.1% and 16.0%, respectively. Addition of aminoguanidine-based ionic liquid (AO-IL) promotes the tribo-chemical reaction of zinc dialkylphosphorodithiloate (ZDDP), distributing S, P and Zn on the cylinder liner honing platform rather than in the honing groove. The plastic deformation causes a significant reduction of flakes on the edges of the cylinder liner honing platforms and less furrow damage along the sliding direction. The worn surface of the diamond-like carbon (DLC) piston ring shows a denser distribution of white bright spots and a higher sp 2 C=C/sp 3 C–C ratio.
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ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Shuo Ma,Donghui Zhang,Zhongli Tang,Wenbin Li,Yanan Zhang,Yating Zhang,Kemeng Ji,Mingming Chen
High-voltage resistant quasi-solid-state polymer electrolytes (QSPEs) are promising for enhancing the energy density of lithium–metal batteries in practice. However, side reactions occurring at the interfaces between the anodes or cathodes and QSPEs considerably reduce the lifespan of high-voltage LMBs. In this study, a copolymer of vinyl ethylene carbonate (VEC) and poly(ethylene glycol) diacrylate (PEGDA) was used as the framework, with a cellulose membrane (CE) as the supporting layer. Based on density functional theory calculations, 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide (Pyr14TFSI), an ionic liquid, was screened because of its lowest unoccupied molecular orbital energy level as a modifying agent for the in situ P(VECx-EGy)/Pyrz/LiTFSI@CE QSPEs synthesis. Pyr14+, with a lithiophobic alkyl chain, forms a dense positive ion shielding layer on the protruding tips of deposited lithium, facilitating uniform and smooth lithium deposition. Pyr14TFSI assists in constructing a stable solid electrolyte interphase (SEI) layer on the Li surface enriched with LiF, Li3N, and RCOOLi. The modulation of lithium deposition behavior on the anode by Pyr14TFSI ensures stable Li plating/stripping for >1500 h. A Li–Cu cell exhibits stable cycling for >200 cycles at a current density of 0.05 mA cm–2, with an average Coulombic efficiency of 92.7%. In situ polymerization ensures that P(VECx-EGy)/Pyrz/LiTFSI@CE QSPEs exhibit excellent interface compatibility with the anode and the cathode. The CR2032 button cell Li|P(VEC1-EG0.06)/Pyr0.4/LiTFSI@CE|LiCoO2 demonstrates stable cycling with a negligible capacity decay of 0.083% per cycle for >390 cycles at 25 °C and 0.2 C when using a high-voltage LiCoO2 (4.45 V) cathode. Furthermore, a 7.1 mAh pouch cell achieves stable charge–discharge cycles, confirming the pronounced stability of the as-fabricated QSPE at the interfaces of the high-voltage LiCoO2 cathode and Li anode.
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COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2024
·
IF 4.9
Zou He,Yang Yang,Yang Wu,Hongsheng Lu
Shale wellbore instability due to hydration significantly hinders the efficient extraction of clean shale gas resources, making the development of effective shale stabilizers for safe drilling in shale reservoirs an urgent priority. In this study, we proposed an innovative application of hydrophobic ionic liquids functionalized nano-SiO 2 (ILs@SiO 2 ) specifically designed to maximize hold wellbore strength and effectively inhibit shale hydration. The chemical composition and microstructure of ILs@SiO 2 were characterized, and their effects on wellbore stability were thoroughly investigated along with the underlying mechanisms. The shale stabilizer demonstrated significant clay swelling inhibition (9.5 %), as well as effective hydration and dispersion inhibition of shale cuttings at 150 °C (88.0 %), and a reduced spontaneous imbibition of shale (0.997 g). Particularly, ILs@SiO 2 maximized maintained wellbore strength (203.4 MPa) and minimized water invasion (5.5 mL). Mechanism analysis revealed that ILs@SiO 2 improved wellbore stability through electrostatic adsorption weakening osmotic hydration, physical plugging establishing a dense preventing water barrier, altering wettability decreasing rocks surface free energy, inhibiting surface hydration, and reversing the direction of capillary forces. This study offers new strategies and insights for constructing methods to plug shale nanopores and inhibit surface and osmotic hydration.
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TRIBOLOGY INTERNATIONAL
·
2024
·
IF 6.1
Yue Lou,Yuxiang Liang,Mengya Zhao,Wenqi Rui,Zhenming Li
Four dual active site ionic liquids (ILs): N2NP0, N4NP0, N6NP0, N10NP0 and three single active site ILs: N2P0, N3P0, N8P0 were synthesized successfully, furthermore, anti-wear and extreme pressure properties of the additives were tested with 0.5 wt% concentration in PAO10 base oil. The results showed that N6NP0 with carbon chain length of six between the nitrogen atoms exhibits the best tribological performance (The wear scar diameter is 0.39 mm, the values of P B (the last non-seizure loads) and P D (weld points) were 135 Kgf and 200 Kgf, respectively), which is mainly attributed to the formed thicker tribo-film (thickness of 50–60 nm) on the friction surface. Through analyzing the tribological morphology, chemical composition and tribo-film microstructure of wear scars surface by SEM-EDS, 3D profile, AFM, XPS and FIB-TEM, the lubrication mechanism of ILs was revealed. Furthermore, density functional theory (DFT) calculations confirmed that the tribological performance of dual active site ionic liquid additives depend strongly on their molecular configuration. It was found that rational adjustment of the length of the ILs cationic active site linkage group results in a reduction of the steric hindrance of the entire molecule. This study will help to guide the design of ILs with good tribological performance and low phosphorus content.
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APPLIED ORGANOMETALLIC CHEMISTRY
·
2024
·
IF 3.7
Fangfang Li,Xiaofang Hou,Ying-Hua Zhou
CO 2 chemical fixation offers a feasible approach for carbon mitigation and high-value utilization, but it is still challenging to develop an efficient catalyst for CO 2 conversion into cyclic carbonate. Herein, the triethylenediamine-derived dicationic ionic liquids (DIL-X, X = Cl, Br, and I) were grafted into UiO-66 linkers through self-assembly of Zr 4+ ions and the mixed ligands of terephthalic acid and DIL-bearing dicarboxylic acid, resulting in UiO-66-DIL-X n , ( n designated as molar amount of the feeding DIL-X). Their catalytic performance was evaluated by the epoxide cycloaddition reaction in the absence of solvent and cocatalyst. Among them, the UiO-66-DIL-Cl 0.4 catalyst exhibited outstanding performance, with a chloropropene carbonate yield of 92% and a high selectivity of 99% under 0.1 MPa CO 2 at 110 °C for 16 h. Its high activity could be ascribed to the cooperativity among Lewis acidity of MOF nodes, the enhanced CO 2 absorption, and the strong nucleophilicity offered by halogen ions of ionic liquid-modified MOF. Moreover, UiO-66-DIL-Cl 0.4 presented excellent recyclability and substrate extension. A potential catalytic mechanism for the epoxide-CO 2 cycloaddition into cyclic carbonate has been proposed. This work will shed light on the rational design of functionalized MOFs-based catalysts for CO₂ utilization.
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BIOSENSORS & BIOELECTRONICS
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2010
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IF 5.429
Xiaoying Liu,Xiandong Zeng,Nannan Mai,Yong Liu,Bo Kong,Yonghong Li,Wanzhi Wei,Shenglian Luo
A colloidal gold-modified carbon ionic liquid electrode was constructed by mixing colloidal gold-modified graphite powder with a solid room temperature ionic liquid n-octyl-pyridinium hexafluorophosphate (OPPF 6 ). Glucose oxidase (GOD) was entrapped in this composite matrix and maintained its bioactivity well and displayed excellent stability. The effect conditions of pH, applied potential and GOD loading were examined. Especially, the glucose oxidase entrapped in this carbon ionic liquid electrode fully retained its activity upon stressing in strongly acidic conditions (pH 2.0) for over one hour. The proposed biosensor responds to glucose linearly over concentration range of 5.0 × 10 −6 to 1.2 × 10 −3 and 2.6 × 10 −3 to 1.3 × 10 −2 M, and the detection limit is 3.5 × 10 −6 M. The response time of the biosensor is fast (within 10 s), and the life time is over two months. The effects of electroactive interferents , such as ascorbic acid , uric acid , can be significantly reduced by a Nafion film casting on the surface of resulting biosensor.
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CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2024
·
IF 3.7
Pengcheng Hu,Jinke Yang,Aonan Lai,Shufeng Zhou
The effects of the structure and concentration of impurities on the alkylation of naphthalene with 1-octene catalyzed by chloroaluminate ionic liquid (IL) were investigated. The presence of impurities containing oxygen and nitrogen led to a decrease in the catalytic performance of chloroaluminate IL. As the water concentration increased to 65 mg·g –1 , the total selectivity of multi-octylnaphthalene gradually decreased to 42.33%, and the average friction coefficient of the multi-octylnaphthalene base oil gradually increased to 0.201. When the concentration of impurities increased to a critical value, the chloroaluminate IL began to deactivate, leading to a decrease in naphthalene conversion. The critical concentrations for ethanolamine, water, methanol, ether, and diisopentyl sulfide were 33 mg·g –1 , 65 mg·g –1 , 67 mg·g –1 , 87 mg·g –1 , and 123 mg·g –1 , respectively. Impurities with higher basicity resulted in an earlier onset of chloroaluminate IL deactivation. The changes of Lewis and Brønsted acids in chloroaluminate IL under the influence of impurities were investigated using in situ IR and 27 Al NMR spectroscopy. 2,6-dimethylpyridine as an indicator could detect the changes of Brønsted acid in chloroaluminate IL better, but the changes of Lewis acid were not obvious because of the overlap between the characteristic peaks. 2,6-dichloropyridine as an indicator could exclusively detect the changes of Lewis acid in chloroaluminate IL. With the increase in water concentration, the Lewis acid in chloroaluminate IL was continuously consumed and converted into Brønsted acid, and the Lewis acid gradually decreased, while the Brønsted acid showed a change of increasing first and then decreasing.
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CHEMISTRY-A EUROPEAN JOURNAL
·
2020
·Vol. 26
·期 7
·1624-1632
·
IF 4.857
Yanqi Wang,Zhipeng Zhu,Zhaofeng Sun,Qianqian Hu,Jianrong Li,Jiang Jiang,Xiaoying Huang
Graphical Fine tweaking . Six heterometallic T5 selenides and their Se/S solid solutions M-In-Q (M=Cu or Cd; Q=Se or Se/S) have been solvothermally synthesized by a two-step method. The T5 selenide clusters, the largest supertetrahedral T n clusters reported to date, show photocatalytic activity that can be tuned according to their constituent components. Although supertetrahedral T n sulfide clusters ( n= 2–6) have been extensively explored, the synthesis of T n selenide clusters with n >4 has not been achieved thus far. Reported here are ionic-liquid (IL)-assisted precursor route syntheses, characterizations, and the photocatalytic properties of six new M-In-Q (M=Cu or Cd; Q=Se or Se/S) chalcogenide compounds, namely [Bmmim] 12 Cu 5 In 30 Q 52 Cl 3 (Im) (Q=Se ( T5-1 ), Se 48.5 S 3.5 ( T5-2 ); Bmmim=1-butyl-2,3-dimethylimidazolium, Im=imidazole), [Bmmim] 11 Cd 6 In 28 Q 52 Cl 3 (MIm) (Q=Se ( T5-3 ), Se 28.5 S 23.5 ( T5-4 ), Se 16 S 36 ( T5-5 ); MIm=1-methylimidazole), and [Bmmim] 9 Cd 6 In 28 Se 8 S 44 Cl(MIm) 3 ( T5-6 ). The cluster compounds T5-1 and T5-3 represent the largest molecular supertetrahedral T n selenide clusters to date. Under visible-light illumination, the Cu-In-Q compounds showed photocatalytic activity towards the decomposition of crystal violet, whereas the Cd-In-Q compounds exhibited good photocatalytic H 2 evolution activity. Interestingly, the experimental results show that the photocatalytic performances of the selenide/sulfide solid solutions were significantly better than those of their selenide analogues, for example, the degradation time of the organic dye with T5-2 was much shorter than that with T5-1 , whereas the photocatalytic H 2 evolution efficiencies with T5-3 – T5-6 improved significantly with increasing sulfur content. This work highlights the significance of IL-assisted precursor route synthesis and the tuning of photocatalytic properties through the formation of solid solutions.
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ACS Sustainable Chemistry & Engineering
·
2024
·
IF 7.1
Jiahui Gong,Mengfei Tian,Ying Liu,Yuting Zhang,Junhui Xing,Qi Liang,Xiaofei Xie,Chunying Li,Chunjian Zhao
In this work, a dual-responsive ionic liquid (DR-IL), namely, [C4mim][FeCl4] was developed for simultaneously extracting and separating hydrophilic phytochemicals, including epicatechin (EC), dihydroquercetin (DQ), ferulic acid (FA), and hydrophobic phytochemicals, such as emodin (ED), chrysophanol (CP), and physcion (PC), from roots of wild Rumex acetosa L. The [C4mim][FeCl4] demonstrates considerable potential for extracting and separating target phytochemicals through temperature adjustment and accelerated phase separation facilitated by a neodymium magnet. Meanwhile, a high recovery yield is obtained by adding a magnetic field. The overall extraction yield of target phytochemicals achieved by [C4mim][FeCl4] reaches 16.12 mg/g under the optimal extraction conditions, representing a 1.53–2.39-fold increase compared to conventional solvents. Furthermore, the molecular simulation and FT-IR analysis reveal that the synergistic effect of van der Waals forces and hydrogen bonds significantly contributed to the higher extraction yields of target phytochemicals.
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CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Shengxin Chen,Bin He,Yingwei Li,Ruirui Wang,Ping Chen,Xingang Li,Ruixia Liu
The selective oxidation of cyclohexane to cyclohexanone and cyclohexanol (KA oils) without additional initiator remains a challenge because of its inherent low activity and limited selectivity. To promote the selectivity of KA oils at high reaction conversion, a series of novel cobalt-based poly(ionic liquid)s (Co-PILs) catalysts were designed. The electronic structure and the microenvironment of Co sites in Co-PILs were regulated by tuning the contents of Co. By the regulation of the microenvironment, the cyclohexane conversion and KA oils selectivity are improved by 19% and 47% (Co-PIL-1–2.5) compared with traditional metal salt catalysts, respectively. Mechanistic studies demonstrated that the electronic structure and coordination environment of transition metals can be effectively tailored. Notably, Co-PILs with low metal loading exhibit a remarkable ability to improve the reaction by transitioning from a low-spin to a high-spin state. Moreover, by adjusting the ratio of cobalt ions to ionic liquid monomers derived from PILs, the acidity, oxygen activation, and desorption of reactive oxygen species were also regulated accordingly. These properties play a pivotal role in the oxidation process, ultimately allowing for precise control over the activity and selectivity.
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NEW JOURNAL OF CHEMISTRY
·
2024
·Vol. 48
·期 7
·3064-3079
·
IF 2.7
Miantuo Li,Fengting Li,Jianwen Hu,Nannan Cui,Huiling Su,Lizhi Li,Zhikun Wang,Shuangqing Sun,Songqing Hu
Three chitosan ionic liquid type Schiff bases (CS-IL-SBs) were synthesized by grafting three aldehydes (vanillin, cinnamaldehyde, and pyridine-4-carboxaldehyde) on CS-IL (chitosan grafted with p-toluene sulfonic acid) through a Schiff base reaction. Thermogravimetric analysis indicated that the thermal stability of CS was enhanced by the modification of IL and Schiff base groups. All CS-IL-SBs present a non-crystalline structure as analyzed using X-ray diffraction technique and have a positively charged surface in solution for improved dispersion stability as analyzed using zeta potential testing. A corrosion inhibition performance investigation using electrochemical and mass loss methods was undertaken, which were supported with surface analysis and computational studies. All the CS-IL-SBs act as effective corrosion inhibitors obeying Langmuir adsorption isotherm containing both chemisorption and physisorption for N80 steel in 15% HCl solution. Among them, CS-IL-Vin (grafted by vanillin) exhibits a maximum inhibition efficiency of 83.66% at 400 mg L−1. The analysis of the corroded metal surface via scanning electron microscopy depicts a considerably smooth morphology in the presence of adsorbed CS-IL-SBs. Contact angle tests indicated that the water-repellent ability of the metal surface was increased by the addition of CS-IL-SBs. Density functional theory calculations indicated that the active regions of CS-IL-SBs are mainly distributed in –SO3−, benzene rings, and Schiff base groups. Molecular dynamics simulations show that CS-IL-SBs are parallelly adsorbed on the metal surface to form a stable protective film. CS-IL-Vin shows the best performance among the three CS-IL-SBs, which was selected to be compounded with aided inhibitors with different electrical properties. When CS-IL-Vin was compounded with negatively charged 3-carboxybenzene sulfonate in a ratio of 1 : 3, corrosion inhibition efficiency was the highest, reaching 93.45%.
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