INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
·
2022
·Vol. 23
·期 20
·12600
·
IF 6.208
Yingjie Luo,Yiwei Zhang,Cimin Tao,Hongfei Ni,Xuesong Liu,Yong Chen,Yongjiang Wu,Hang Song,Tengfei Xu
Imidazolium-based ionic liquids are wildly used in natural product adsorption and purification. In this work, one typical polymeric ionic liquid (PIL) was synthesized by using L-proline as the anion, which exhibited excellent adsorption capacity toward tea polyphenol epigallocatechin gallate (EGCG). The adsorption conditions were optimized with the response surface method (RSM). Under the optimum conditions, the adsorption capacity of the PIL for EGCG can reach as high as 552 mg/g. Dynamics and isothermal research shows that the adsorption process of EGCG by the PIL particularly meets the quasi-second-order kinetic equation and monolayer adsorption mechanism. According to thermodynamic parameter analysis, the adsorption process is endothermic and spontaneous. The results of theoretical calculation by molecular docking also demonstrated the interaction mechanisms between EGCG and the ionic liquid. Considering the wide application of imidazolium-based ionic liquids in component adsorption and purification, the present study can not only be extended to other similar experimental mechanism validation, but also be representative for guiding the synthesis of PIL and optimization of adsorption conditions.Keywords:ionic liquids;polymer;epigallocatechin gallate;mechanism;molecular docking
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高影响因子
PROPELLANTS EXPLOSIVES PYROTECHNICS
·
2022
·Vol. 48
·期 2
·e202200186
·
IF 2.134
Xikai Duan,Zhaoqian Li,Bo Wu,Jinpeng Shen,Chonghua Pei
The industrial nitrification system of preparing nitrocellulose (NC) adopts nitric and sulfuric mixed acid, which generates a large amount of waste acid and by-products, and requires a laborious procedure for the stability treatment. In this study, a novel method was developed for the preparation of NC. NC with a nitrogen content of 12.62 % was prepared in 15 min by homogeneous esterification of cellulose based on [Bmim]Cl (1-butyl-3-methylimidazolium chloride). The samples were characterized by FT-IR, XRD, Raman, XPS, TG-DSC, GPC, SEM, and elemental analysis. In addition, the activation energy (Ea) was calculated according to the Kissinger method. The burning rate and chemical stability of samples were also tested. The results showed that the NC had 3D honeycomb structure with pores of 200–300 nm diameter, uniform distribution of nitrogen elements, nitrogen content of 12.62 %, and minimum polydispersity index (PDI) of 1.55. The heat of decomposition (Q dec ) released by the samples was increased by 141 J/g, the Ea decreased by 16.4 %, and the burning rate increased by 40.5 % when compared with commercially available NC 12.6% . The chemical stability was very well only after water cooking. Compared with the conventional method, this method doesn't use sulfuric acid, generates less waste acid, and doesn't produce by-products such as sulfate esters. The procedure of stability treatment was also very effortless. The costs could also be reduced by the recycling of ionic liquids.
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TRIBOLOGY LETTERS
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2022
·Vol. 70
·期 2
·1-16
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IF 3.327
Wang Peng,Gao Peng,Ma Lin,Wen Ping,Han Yunyan,Dong Rui,Fan Mingjin
In this paper, four ionic liquids based on chromotropate (CAILs) were prepared and applied to heighten the tribological performance of aqueous system on different metal friction contacts. Taking for the potential choice for water-based lubricating additive, CAILs exhibited excellent water solubility and corrosion resistance. Tribological results showed that the CAILs, especially the phenolic hydroxyl group decorated samples (TsnN 4444 and TsnP 4444 ), demonstrating extremely effective lubricating properties with the efficient friction and wear descent (69% and 83% for Fe, 47% and 94% for Cu, 74% and 69% for Al, respectively). Especially, the excellent load-carrying capacity was also presented with the highest P B (833 N) and P D (1568 N) values for TsnP 4444 . It is speculated that the CAIL molecular adsorption on the interface and further generation of tribochemical films are beneficial for their lubricating effects, resulting from the systematic discussion and analysis of CA, QCM, SEM, XPS, and FIB-TEM tests. However, TsN 4444 and TsP 4444 showed less effective lubricating performances and poor load-carrying capacities due to tribocorrosion of hydroxyl groups at the interface. Graphical Abstract
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JOURNAL OF MOLECULAR LIQUIDS
·
2022
·
IF 6.633
Jia Wei,Hongshuai Gao,Yao Li,Yi Nie
Utilizing phosphate-based ionic liquids (ILs) solvents for dissolving cellulose to prepare cellulose fibers has attracted much attention for its convenience, high yield, stability and sustainability. However, the degradation behavior during dissolving of cellulose in ILs, which is an important factor for fabricating cellulose fiber, is still unclear. In this work, the degradation of wood pulped cellulose (WPC) in three kinds of phosphate-based ILs: 1-ethyl-3-methylimidazolium dimethyl phosphate ([Emim]DMP), 1-ethyl-3-methylimidazolium diethyl phosphate ([Emim]DEP) and 1-butyl-3-ethylimidazolium diethyl phosphate ([Beim]DEP), were systematically investigated at different dissolution temperatures and dissolution times. The results indicated that the degradation degree of WPC in three ILs follows the order of [Emim]DEP > [Beim]DEP > [Emim]DMP, which is consistent with interaction results obtained by quantum chemical calculation, and degradation degree increases follows the rising of dissolution temperature and the accumulation of dissolution time. Moreover, no reducing sugar (RS) was found in any recycled ILs even when the degree of polymerization (DP) of regenerated cellulose (RC) decreased by 30.4%. In addition, according to the Fourier transform infrared and X-ray diffraction data, the results further proved that the crystallization type of RC changed from type Ⅰ to type Ⅱ. Here, preferable dissolving parameters and experiments data of multiple conditions are provided, which may provide practical reference and guidance for both scientific research and industrial.
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高影响因子
ELECTROCHEMISTRY
·
2022
·Vol. 90
·期 2
·027006-027006
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IF 1.777
Aimin LIU,Mengxia GUO,Yubao LIU,Fengguo LIU,Xianwei HU,Zhongning SHI
In this work, the Zn–Ta coating was electrodeposited from DMI–ZnCl2–TaCl5 solvate ionic liquid. The electrochemical reaction was studied by cyclic voltammetry using titanium as working electrode. The onset potential of zinc and tantalum co-deposition was −0.7 V (vs. Ag). Moreover, potentiostatic electrodeposition experiments were conducted to investigate the influence of potential and temperature on the morphology of the coating. X-ray photoelectron spectroscopy analysis confirmed that the coating obtained by electrodeposition at −1.6 V (vs. Ag) and 353 K was composed of Zn, Ta, ZnO, and Ta2O5. The mass fraction of element tantalum was 6.21 %, and metallic tantalum accounted for 11.54 % of the mass of element tantalum. The corrosion current density of the Zn–Ta coating was 1.83 × 10−4 A cm−2.
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高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2023
·
IF 6
Kun Yuan,Kehuai Feng,Sheng Liao,Xiaoning Liao,Yichen Zou,Dan Hou,Xuliang Nie,Wanming Xiong
In recent years, functionalized ionic liquids (ILs) have attracted widespread interest due to their unique physicochemical properties. Accordingly, in this work, a series of phenyl-coupled diimidazolium hexafluorophosphate ionic liquids (P-DRIMF) with different R-groups in the sidechain of the imidazolium ring were synthesized and characterized. Moreover, their electrochemical properties, e.g., electrochemical window, impedance, and stability, were further investigated via electrochemical analysis. Results showed that the IR, 1 H NMR, and X-ray diffraction of P-DRIMF match well with the expected structures, as well as they were crystallized and belong to monoclinic or triclinic systems. On the other hand, the electrochemical window could increase from 2.73 V to 3.28 V with the extended alkyl sidechain R-group of the imidazolium ring, and the unsaturated vinyl group would result in a worse electrochemical window. Notably, modified glassy carbon electrodes (ILs/GCE) could perform low impedance, high stability, and improve the electrochemical response. In this case, there was a 2- to 4-fold improvement in response to phenolic compounds, while the response to other compounds still needs further improvement. Overall, this work may shed light on the design of ILs and their applications in electrochemistry.
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SEPARATION AND PURIFICATION TECHNOLOGY
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2020
·
IF 5.774
Qi Zhang,Siru Ren,Song Xue,Ang Li,Siyao Liu,Xiaodong Sun
In the field of separation science, the use of tartaric acid-based ionic liquids (TTILs) for chiral separation has not yet been reported. In this work, six novel mono- and di-tetraalkylammonium l -tartrate ILs (TAA- l -TTs) with different alkane chain length were evaluated for their potential as sole chiral selectors in capillary electrophoresis (CE). In comparison with conventional l -tartaric acid ( l -TT) chiral selector, these IL-type chiral selectors exhibit remarkably improved enantioseparation performance, which is even better than most previously reported TT ester-type chiral selectors. Major factors influencing CE separation were investigated, including the background electrolyte (BGE) composition, ILs concentration, type and proportion of organic modifier, buffer pH, etc. The results show that the l -TT-based IL-type chiral selectors prefer a weak acid buffer (150 mM boric acid at pH 4.5) with a high proportion of methanol (80%-90%). The best resolutions (Rs) were obtained when the IL concentration was set at 60 mM. We further carried out a series of comparative experiments and a molecular simulation study to explore the enantiorecognition mechanism of TTILs. The result indicates that the TAA- l -TTs cannot be considered as a simple combination of TAA salt and l -TT. The dissociation degree of TTILs may be an important factor influencing the enantiorecognition process.
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AICHE JOURNAL
·
2020
·Vol. 66
·期 8
·e16979
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IF 3.519
Piao Cao,Yuan Yuan,Chizhou Huang,Weizhen Sun,Ling Zhao
Seven typical quaternary ammonium ionic liquids, amino acid ionic liquids, and imidazolium ionic liquids were synthesized, characterized, and investigated as co-catalyst for the sulfuric acid catalyzed isobutane alkylation. The results show that the introduction of [OPSIm][HSO 4 ] or [Pr 3 NPS][HSO 4 ] both leads to a better catalytic performance and higher quality of alkylate products. The molecular dynamic simulation indicates that the [OPSIm][HSO 4 ] can promote the dissolution of isobutane molecules at interface, further improving the ratio of isobutane to olefin from 1.02 to 1.18. Differently, the [Pr 3 NPS][HSO 4 ] can significantly increase the interface width from 0.66 to 0.97 nm and reduce the interface tension from 28.49 to 14.62 mN/m, thereby enhancing the reaction area and improving the ion transfer. The [Pro][HSO 4 ] and [Gly][HSO 4 ] result in a worse quality of alkylate products due to no positive effect on the interfacial properties such as interfacial solubility of isobutane.
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JOURNAL OF MOLECULAR LIQUIDS
·
2020
·
IF 5.065
Lili Zhang,Yigang Ding,Bingwen Long,Lin Yao,Haiyuan Yuan,Yafen Dai
In this work, polymeric ionic liquids (PILs) based on imidazolium ionic liquid monomer , which possessed hierarchical porous structure and rich Lewis basic sites, could effectively adsorb both large-sized and small molecular phenolic compounds from aqueous solution. The maximum adsorption capacities of the as-synthesized PILs for tannic acid (TA), 4-nitrophenol (4-NP) and 4-chlorophenol (4-CP) reached as high as 911 mg/g, 460 mg/g and 433 mg/g, respectively. The capacity for TA was the highest among the existing adsorbents. The abundant Lewis basic sites (N-atom and Cl − ) provided by imidazolium ionic liquids and the special hierarchical porous structure of PILs were responsible for its excellent phenolic adsorption performance. The adsorption equilibrium data of 4-NP and 4-CP fitted well with the Freundlich model while those of TA complied better with the Langmuir model. The mechanism analysis indicated that the adsorption for 4-NP and 4-CP was mainly due to π–π interactions, and that for TA was dominated by H-bonding and electrostatic interaction. The PILs could be easily regenerated. This study provided a novel material for the treatment of phenolic wastewater.
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高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2020
·
IF 5.065
Qingshan Liu,Liansheng Ma,Kexin Li,Jian Wang,Ying Zang
The density of four ionic liquids 1-alkyl-2-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide ([C 2 mim][NTf 2 ] and [C 4 mim][NTf 2 ]), 1-alkyl-2, 3-dimethylimidazolium bis[(trifluoromethyl)sulfonyl]imide ([C 2 mmim][NTf 2 ] and [C 4 mmim][NTf 2 ]) have been determined with Dimethyl Carbonate (DMC) at lower concentration from 288.15 to 313.15 K at atmospheric pressure. Apparent molar volumes , V ϕ /m 3 ·mol −1 , have been calculated from the experimental densities. The effects of the methyl or methylene groups of the imidazolium cation on the above properties are discussed in deeply. The infinite dilution apparent molar volumes , V ϕ 0 /m 3 ·mol −1 can be obtained from apparent molar volumes according to a Redlich-Rosenfeld-Meyer equation. The limiting apparent molar expansibility, E ϕ 0 /cm 3 ·mol −1 ·K −1 , have been calculated by the parameters from Redlich-Rosenfeld-Meyer equation. The thermal expansion coefficient , α /K −1 , has also been calculated in the studied concentration range.
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MICROCHEMICAL JOURNAL
·
2021
·
IF 4.821
Wenjin Li,Yunchang Fan,Sheli Zhang,Jing Li,Lei Zhang,Hongwei Wu
The isolation of bioactive compounds from natural sources using conventional solvents has always suffered from the poor extraction ability and tedious extraction procedure. Ionic liquids (ILs) have emerged as the alternatives to conventional solvents due to their high extraction ability and low-toxic nature. In this work, a series of protic ILs was prepared via acid-base reaction using non-to-mild toxic organic acids and bases as starting materials. The synthesized protic ILs in combination with microwave-assisted extraction (ILs-MAE) were used to extract rosmarinic acid (RA) from Perilla seeds. Optimal extraction conditions were 5% of IL concentration, 50 s of microwave irritation time, 350 W of microwave irritation power and 50 g g −1 of liquid–solid ratio. Acidity of ILs and the extraction temperature played an important role in the extraction process. Compared with heating reflux extraction (HRE), ultrasound-assisted extraction (UAE) and maceration (MAC), the IL-MAE exhibited highest extraction ability and fastest extraction rate. After extraction, the IL could be recycled without losing its extraction ability via back extraction of RA with ethyl acetate. The RA in the ethyl acetate extract was further purified by column chromatography and high purity of RA (90.4%) could be obtained. These findings suggest that IL-MAE is promising method for the isolation of bioactive compounds from natural plants.
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CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
·
2019
·Vol. 36
·期 5
·865-869
·
IF 1.071
Yu Fengli,Chi Yujie,Gao Chong,Chen Ruirui,Xie Congxia,Yu Shitao
A series of amino-acid-based ionic liquids was synthesized via one-step protonation of the corresponding L -amino acid by utilizing an array of proton sources. The catalytic activity of the amino-acid-based ionic liquids for the Baeyer-Villiger oxidation of cyclic ketones was investigated using cyclopentanone as a model cycloketone. The proline-based ionic liquid [ProH]CF 3 SO 3 was shown to exhibit the best catalytic activity. The reaction condition was optimized to give the following reagent ratio of n (cyclopentanone): n (catalyst): n (H 2 O 2 )=1:0.06:4, 60 °C and 6 h. Under the optimum conditions, the conversion of cyclopentanone was 96.57% and the selectivity for δ-valerolactone was 73.01%. The catalytic activity was shown to be constant after 4 cycles. A simple treatment was allowed for the recover and the reuse of [ProH]CF 3 SO 3 . The successful utilization of [ProH]CF 3 SO 3 to catalyze a host of cyclic ketones via Baeyer-Villiger oxidation clearly demonstrated the capacity of [ProH]CF 3 SO 3 to tolerate variation in the substrate.
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危险品化学品经营许可证（带存储）