Journal of Pharmaceutical Analysis
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2013
·
IF 0
Nan Zhou,Xia-Shi Zhu
Ionic liquids functionalized β-cyclodextrin polymer, a mono-6-deoxy-6-(1,2-dimethylimidazolium)-β-cyclodextrin iodide polymer (ILs-β-CDCP), was synthesized as a solid-phase adsorbent coupled with high-performance liquid chromatography for separating or analyzing magnolol in drug samples. The results showed that magnolol was adsorbed rapidly on ILs-β-CDCP and eluted with methanol. Under the optimum conditions, preconcentration factor of the proposed method was 12. The linear range, limit of detection (LOD), correlation coefficient ( R ) and relative standard deviation (RSD) were found to be 0.02–8.00 μg/mL, 1.9 ng/mL, 0.9992 and 2.76% ( n =3, c =2.00 μg/mL), respectively. The interaction between ILs-β-CDCP and magnolol was studied through the inclusion constant, FTIR and TGA analysis. This proposed method has been successfully applied to the determination of magnolol in real samples.
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CHEMICAL ENGINEERING & TECHNOLOGY
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2017
·Vol. 40
·期 10
·1784-1791
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IF 2.051
Zhenyu Yang,Yufeng Hu,Weiting Ma,Jianguang Qi,Xianming Zhang
Polyoxymethylene dimethyl ethers (PODE n ) are widely applied as diesel additives in engines. Ionic liquids (ILs) replace traditional liquid acids as catalysts in chemical processes. A series of pyrrolidinonium-based Brønsted acidity ILs were synthesized, investigated, and employed as catalysts for the synthesis of PODE n from methylal and trioxane for the first time. The Hammett function values were measured to uncover the connection between catalytic performance and acidity-activity of the ILs considered. The optimal experimental conditions for the synthesis of PODE n were determined. The maximum values of both the conversion of raw material and the selectivity of PODE 3–8 were obtained with 1-octyl-2-pyrrolidinonium trifluoromethanesulfonate ([NOP][TFO]) as the catalyst. [NOP][TFO] provides greater selectivity of PODE 3–4 than the traditional catalysts such as H 2 SO 4 and CF 3 SO 3 H.
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ENERGY & FUELS
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2017
·
IF 3.091
Zhongqi Ren,Mengyao Wang,Yong Li,Zhiyong Zhou,Fan Zhang,Wei Liu
The designer nature of ionic liquids (ILs) has driven their exploration and application in countless fields because of their unique phiscochemical properties. In this work, two ester-functionalized ionic liquids (ILs), N-ethyl acetate-N-methylimidazole bis(trifluoromethylsulfonyl)imide ([Eamim][NTf2]) and N-ethyl acetate-N-methylimidazole sulfocyanide([Eamim][SCN]), were prepared. Two ternary systems, benzene-hexane-[Eamim][NTf2] and benzene-hexane-[Eamim][SCN], were investigated in terms of both quantum chemical calculation and liquid–liquid extraction experiments. Quantum chemical calculation results showed that the interaction between ILs and benzene was larger than that between ILs with n-hexane. The liquid–liquid extraction results showed that the selectivity reached 29.55 with [Eamim][NTf2], while the selectivity reached 61.44 with [Eamim][SCN] at 25 °C. The vapor permeation process was conducted through a supported membrane with ILs. The influences of operating temperature and the feed concentration of benzene were investigated. With the increase of temperature, the selectivity of benzene increased at first and then decreased. When the concentration of benzene was 0.5 and the temperature was 35 °C, the selectivity of benzene reached 16.05, while the flux was 22.14 g·h–1·m–2. The stability of the membrane in the vapor permeation was also tested and could remain steady for 60 h.
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Journal of Energy Chemistry
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2017
·
IF 2.594
Haiying Ran,Jiexin Wang,Ahmed A. Abdeltawab,Xiaochun Chen,Guangren Yu,Yinghao Yu
We synthesized one quaternary ammonium polymeric ionic liquids (PILs)P[VBTHEA]Cl and three imidazolium PILs of P[VEIm]Br, P[VEIm]BF 4 , P[VEIm]PF 6 by free-radical polymerization in solution. These PILs were characterized by FT-IR, 1 H-NMR, 13 C-NMR, TGA, XRD and SEM. Their CO 2 adsorption capacities were measured under different pressures and temperatures by constant-volume technique. It was observed that quaternary ammonium PILs of P[VBTHEA]Cl have higher adsorption capacity for CO 2 than those imidazolium PILs, following P[VBTHEA]Cl > P[VEIm]PF 6 > P[VEIm]BF 4 > P[VEIm]Br, which may be ascribed to higher positive charge density on ammonium cation than that on imidazolium cation and thus stronger interaction with CO 2 , consistent with the results from dual-mode adsorption model that ammonium PILs have much higher CO 2 bulk absorption than imidazolium PILs. CO 2 adsorption capacity of P[VBTHEA]Cl is 9.02 mg/g under 295 K and 1 bar, which is comparable to that of some other PILs, and is much higher than that of the corresponding ILs monomer . These PILs have good adsorption selectivity for CO 2 over N 2 and regeneration efficiency.
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MOLECULES
·
2014
·Vol. 19
·期 12
·20157-20169
·
IF 2.095
Caili Dai,Mingyong Du,Yifei Liu,Shilu Wang,Jianhui Zhao,Ang Chen,Dongxu Peng,Mingwei Zhao
Micelles formed by the long-chain piperidinium ionic liquids (ILs)N-alkyl-N-methylpiperidinium bromide of general formula CnPDB (n= 12, 14, 16) in ethylammonium nitrate (EAN) were investigated through surface tension and dissipative particle dynamics (DPD) simulations. Through surface tension measurements, the critical micelle concentration (cmc), the effectiveness of surface tension reduction (Πcmc), the maximum excess surface concentration (Гmax) and the minimum area occupied per surfactant molecule (Amin) can be obtained. A series of thermodynamic parameters (ΔGm0,ΔHm0andΔSm0) of micellization can be calculated and the results showed that the micellization was entropy-driven. In addition, the DPD simulation was performed to simulate the whole aggregation process behavior to better reveal the micelle formation process.Keywords:aggregation behavior;long-chain piperidinium ionic liquid;surface tension;dissipative particle dynamics
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JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2017
·
IF 2.323
Xiaopo Wang,Yao Zhang,Dongbo Wang,Yanjun Sun
In recent years, trans-1,3,3,3-tetrafluoropropene (R1234ze(E)) was proposed as a possible replacement for hydrofluorocarbons. In this work, the vapor–liquid phase equilibrium of R1234ze(E) with three imidazolium ionic liquids (ILs) were measured from (283.15 to 343.15) K based on the isochoric method. The ILs include 1-ethyl-3-methylimidazolium tetrafluoroborate ([Emim][BF4]), 1-hexyl-3-methylimidazolium tetrafluoroborate ([Hmim][BF4]), and 1-octyl-3-methylimidazolium tetrafluoroborate ([Omim][BF4]). The experimental results were correlated using the nonrandom two-liquid activity coefficients model. The deviations between experimental data and calculated values for pressure were 1.77%, 2.07%, and 2.32% for R1234ze(E) + [Emim][BF4], + [Hmim][BF4], and + [Omim][BF4] systems, respectively.
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Reaction Chemistry & Engineering
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2024
·
IF 3.4
Minmin Liu,Bingxi Song,Yanhui Hu,Xianglei Meng,Renzheng Jiang,Yanyan Diao,Yuting Song
Following the principle of sustainable and green development, the environmentally friendly and highly efficient manufacturing of fluorine chemical products is becoming an unavoidable development trajectory. Ionic liquid catalysts have shown great potential to replace traditional metal salt catalysts, which cause environmental pollution, in the dimerization of perfluorinated olefins. In this study, a series of strong nucleophilic thiocyanate ionic liquids with various cationic structures were designed and synthesized. The catalytic activity of 4-dimethylaminopyridine (DMAP) ionic liquids exceeded that of reported catalysts, being 2.4 times higher than that of traditional metal salt catalysts, and 1.5 times higher than that of imidazole ionic liquids reported in the literature. Under the optimal reaction conditions, the high turnover frequency (TOF) value of the [C6DMAP][SCN] catalyst performance reaches 325.04 h−1. Based on the experimental results, density functional theory (DFT) and XPS analysis, the excellent catalytic performance of [C6DMAP][SCN] can be attributed to the dual active sites of anions and cations, and a dual-activation reaction mechanism is further proposed. This study not only expands the application of ionic liquid in the hexafluoropropylene dimerization reaction but also helps establish a more efficient, green, and sustainable catalytic process for hexafluoropropylene dimerization.
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CATALYSIS LETTERS
·
2024
·
IF 2.3
Shao Yulin,Xie Ping,Han Yuning,Zhong Tianhao,Li Tao,Yu Yingmin,Zhao Qingshan,Li Zhongtao
In response to the problem that the conventional concentrated sulfuric acid catalyst for esterification reactions are prone to corrosion and generate large amounts of acid-containing wastewater, highly efficient gel resin-loaded ionic liquid solid acid (SA-ILs) catalysts were prepared by a one-pot method of loading ionic liquids onto gel resins. It is shown that the gel resin carrier has a strong water-absorbing structure, and the ionic liquids are covalently loaded on the gel resin carrier through chemical bonding, leading to SA-ILs catalysts with excellent acidity and good structural stability. With an optimal ionic liquid loading of 11% and acid density of 3.25 mmol·g −1 ,the synthesized SA-ILs catalysts showed good catalytic performance in the transesterification reaction between acetic acid and ethanol at 80 °C for 1.5 h. The catalyst dosage was 10 wt% of the total mass of acetic acid and ethanol, and the ethanol to acetic acid addition was at a molar ratio of 1.5:1. Ethyl acetate yields of up to 81% were achieved after the reaction. The catalyst also showed slightly decrease of the catalytic performance after reused for five cycles. The lower activation energy of the catalyst is proved to be the key to facilitate the catalytic transesterification reaction. Graphical Abstract
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CARBOHYDRATE POLYMERS
·
2025
·
IF 12.5
Qingqing He,Jinghai Chen,Guangjun Tan,Ruimeng Wang,Hongbing Ji,Zhongxing Zhao,Zhenxia Zhao,Kungang Chai,Liqin Zhou
Formaldehyde (HCHO) is a major pollutant among indoor volatile organic compounds (VOCs) and has been categorized as a Group 1 carcinogen by the World Health Organization. Designing and preparing green and environmentally friendly porous bio-adsorbents for efficient adsorption of HCHO is essential. This study developed a novel porous starch-graft-styrene hypercrosslinked polymer (IL@H-St-g-PS) for efficient HCHO adsorption through post-modification strategy using ionic liquids (ILs). Firstly, [EMIm][OAc] was selected in four ILs by theoretical calculation due to the strongest binding energy with HCHO. Then, H-St-g-PS was modified with [EMIm][OAc] and thus the product IL@H-St-g-PS possessed abundant adsorption sites such as starch hydroxyl groups, acetate ions and imidazole groups in ILs. The prepared IL@H-St-g-PS had a high BET surface area (645 m 2 /g) with a micropore volume and reached an HCHO adsorption capacity at 15.0 mg/g at 350 ppm, which was approximately 2.0 times greater than that of the original H-St-g-PS. The adsorption of HCHO on glucose units of starch and ionic liquid units within IL@H-St-g-PS could be enhanced through hydrogen bonding and electrostatic interactions. These results suggested that the ILs modified starch-based polymer could provide an environmentally friendly and attractive candidate adsorbent for the adsorption of aldehyde VOCs in practical applications.
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ACS Applied Polymer Materials
·
2024
·
IF 4.4
Manman Zhang,Liu Chen,Kaifang Wang,Ruitao Lin,Zeshen Xiao,Raphael Semiat,Xuezhong He
The development of materials has given rise to the study and design of poly(ionic liquid)s (PILs) for making CO2-selective membranes. The huge design space for the chemical structures of PILs provides great opportunities to further investigate the factors underlying gas permeability and selectivity. Herein, copolymerizing imidazolium-based ionic liquid (IL) monomers with two functionalized monomers of acrylamide (AM) and butyl acrylate (BA) based on free radical polymerization was conducted, and the effect of the chemical structures for PIL-based copolymers on their performances of derived membranes for CO2/N2 separation was evaluated. Nuclear magnetic resonance (NMR) and Fourier transform infrared (FTIR) spectroscopy analysis confirmed the successful synthesis of copoly(ionic liquids) (co-PILs) with the designed chemical structures. The co-PIL-based composite membranes were fabricated by coating the copolymer solutions on the surface of a commercial polysulfone (PSF) membrane. It was found that the best composite membranes present significantly enhanced CO2 permeance (76 GPU) and CO2/N2 selectivity (53) by 262% and 61% compared to pure PSF membranes. The proposed coating method using co-PILs provides a facile solution to improve the CO2 separation membrane performance. Therefore, molecular engineering of the chemical structures for poly(ionic liquids) opens a venue to develop high-performance co-PIL-based membranes for potential CO2 capture from flue gases.
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INDUSTRIAL LUBRICATION AND TRIBOLOGY
·
2024
·Vol. 76
·期 6
·842-851
·
IF 1.5
Long Sun,Chengjie Jin,Xiaodong Tang,Kexin Cao,Songquan Wang,Ningning Hu
PurposeThe purpose of this paper is to solve the abrupt deterioration of lubricant performance in high-temperature conditions.Design/methodology/approachThree silver pyrazolyl methyl pyridine complexes with different morphologies were synthesized. A four-ball tribometer was used to assess the tribological characteristics as an additive for pentaerythritol oleate both independently and compound with 1-hexyl-3-methylimidazolium bis(trifluoromethane sulfonyl)imide.FindingsThe results showed that when silver complexes and ionic liquids (IL) act independently, sheet silver complex 1 and rod silver complex 2 exhibit good lubricating performance; the optimal antifriction concentration of the ILs is 0.25 Wt.%. The tribological results of the compounds additive of ILs and silver complexes indicate that the wear scar diameter of compound 1 decreased by 16.914%, the wear volume reduced by 7.44% and the lubrication effect surpassed that of the two substances individually; rod compound 2 exhibited an antagonistic effect, intensifying wear; compound 3’s lubrication effect fell between that of the two individual components.Originality/valueThe compound of sheet silver complexes and ILs effectively solves the agglomeration problem of micro/nano lubricant additives. When the interface fails, self-repair is completed, improving the stability and antiwear performance of the lubricating oil.Peer reviewThe peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-04-2024-0128
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CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Weida Chen,Meisi Chen,Bin Jiang,Tong Lei,Feng Zhang,Zhibing Zhang
Biphasic absorbents composed of tetraethylenepentamine, 1-ethylimidazole, and H 2 O (TEH) exhibit notable absorption rates and CO 2 loads. However, troublesome precipitation forms in the enriched phase due to strong interactions among absorption products. To address this issue, six amino acid ionic liquids (AAILs) were introduced as split-phase regulators in TEH, developing a liquid–liquid biphasic absorption system TEH-AAILs, with outstanding absorption performance. By analyzing the kinetic data and establishing the evaluation parameters, combined with molecular dynamics simulations, the effects of AAILs on the loading and phasing performance were assessed. Remarkably, TEH-[Ser] was screened to possess good performance. Spectral analysis of the TEH-[Ser] reaction mechanism further elucidates the bridged hydrogen bonding structure between [Ser]–CO 2 and H 2 O, highlighting its role in enhancing regeneration efficiency. This study provides insights into the design and optimization of biphasic absorbents for efficient CO 2 capture.
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