Ionic liquids(ILs)are an emerging class of media of fundamental importance for chemical engineering,especially due to their interaction with solid surfaces.Here,we explore the growth phenomenon of surface-confined ILs...Ionic liquids(ILs)are an emerging class of media of fundamental importance for chemical engineering,especially due to their interaction with solid surfaces.Here,we explore the growth phenomenon of surface-confined ILs and reveal a peculiar structural transition behavior from order to disorder above a threshold thickness.This behavior can be explained by the variation of interfacial forces with increasing distance from the solid surface.Direct structural observation of different ILs highlights the influence of the ionic structure on the growth process.Notably,the length of the alkyl chain in the cation is found to be a determining factor for the ordering trend.Also,the thermal stability of surface-confined ILs is investigated in depth by controlling annealing treatments.It is found that the ordered monolayer ILs exhibit high robustness against high temperatures.Our findings provide new perspectives on the properties of surface-confined ILs and open up potential avenues for manipulating the structures of nanometer-thick IL films for various applications.展开更多
Benzoin condensation promoted efficiently in three imidazolium based room tempera- ture ionic liquids [bmim]Br, [bmim]BF4 and [Bnmim]BF4 is reported for the first time. Benzoins were obtained in up to 91% yield within...Benzoin condensation promoted efficiently in three imidazolium based room tempera- ture ionic liquids [bmim]Br, [bmim]BF4 and [Bnmim]BF4 is reported for the first time. Benzoins were obtained in up to 91% yield within less than 30 min under mild conditions.展开更多
The fluorination reaction involving a β-ketosulfones by Selectfluor^TM was efficiently promoted by the ionic liquid, [Hbim]BF4 (IL) as a reaction medium with methanol as co-solvent at room temperature under ultraso...The fluorination reaction involving a β-ketosulfones by Selectfluor^TM was efficiently promoted by the ionic liquid, [Hbim]BF4 (IL) as a reaction medium with methanol as co-solvent at room temperature under ultrasonic irradiation to afford the corresponding mono and difluoro-β-ketosulfones in excellent yields. The advantages of this method include among others the use of a recyclable, non-volatile ionic liquid, which promotes this protocol under room temperature without the requirement of any added catalyst under ultrasonic irradiation.展开更多
Economically separating 1-propanol(NPA)from water is an emergent issue for producing pharmaceutical intermediates such as n-propyl acetate,n-propylamine and so on.In this work,fourionic liquids(ILs)1-ethyl-3-methylimi...Economically separating 1-propanol(NPA)from water is an emergent issue for producing pharmaceutical intermediates such as n-propyl acetate,n-propylamine and so on.In this work,fourionic liquids(ILs)1-ethyl-3-methylimidazolium thiocyanate([EMIM][SCN]),1-butyl-3-methylimidazolium tetrafluoroborate([BMIM][BF_(4)]),1,3-dimethylimidazolium methylsulfate([MMIM][MS]),1,3-dimethylimidazolium dimethylphosphate([MMIM][DMP])were introduced as potential entrainers for separating NPA–water azeotropic mixture.The results show that[MMIM][MS]is the most suitable entrainer compared with other ILs from the analysis of vapor-liquid equilibrium and relative volatilities.The extractive distillation process with the entrainer regeneration system of flash tank and stripper was employed and optimized by the two-step optimization method.The results show that total annual cost and energy consumption per product flow rate were reduced by 39.79%and 60.47%compared with literature.In addition,the efficiency indicator of extractive section,efficiency indicator of per tray in extractive section,carbon dioxide emissions were also selected as the evaluation index for selection of operating parameters and calculated for different cases.The CO_(2)emissions of the optimal design can be reduced by 60.98%from environmental aspect.展开更多
The controllable molecular weight and polydispersity of polyacrylonitriles(PANs) were synthesized in ionic liquids(ILs) by atom transfer radical polymerization(ATRP) using ethyl-2 bromopropionate(EPN-Br) as initiator ...The controllable molecular weight and polydispersity of polyacrylonitriles(PANs) were synthesized in ionic liquids(ILs) by atom transfer radical polymerization(ATRP) using ethyl-2 bromopropionate(EPN-Br) as initiator and CuBr/pentamethyldiethylenetria-mine(PMDETA) as catalyst.The polydispersity index(PDI) in the ATRP of acrylonitriel(AN) in ILs is lower than 1.3.From the polymerization kinetics,plots of ln([M]0/[M]) with time show a linear dependence at the early stage of polymerization while the deviation is observed with the conversion rate increasing.The polymerization rate in ILs,especially in 1-butyl-3-methylimidazolium chloride([bmim]Cl),is higher than that in N,N-dimethylformamide(DMF).The polymerization rate increased and the average molecular weight decreased with temperature increasing.The polymerization rate,molecular weight and PDI varied with the variation of [AN]0:[EPN-Br]0:[CuBr]0:[PMDETA]0 ratio in the experimental range,the polymerization of AN in [bmim]Cl displayed living polymerization characteristics.Moreover,the catalyst and ILs are easily isolated from the polymer and reused.展开更多
The adjustable parameters in the popular conductor-like screening model for real solvents(COSMO-RS)within the Amsterdam density functional(ADF)framework have been re-optimized to fit for the systems containing ionic l...The adjustable parameters in the popular conductor-like screening model for real solvents(COSMO-RS)within the Amsterdam density functional(ADF)framework have been re-optimized to fit for the systems containing ionic liquids(ILs).To get the optimal values of misfit energy constant a^0,hydrogen bond coefficient c_(hb)and effective contact surface area of a segment a_(eff),2283 activity coefficient data points at infinite dilution and 1433 CO_2 solubility data points exhaustively collected from references were used as training set.The average relative deviations(ARDs)of activity coefficients at infinite dilution and CO_2 solubility between experimental data and predicted values are 32.22%and17.61%,respectively,both of which are significantly lower than the original COSMO-RS versions.Predictions for other activity coefficients of solutes in ILs,solubility data of CO_2 in pure ILs and the binary mixtures of ILs at either high or low temperatures,and vapor–liquid equilibrium(VLE)for binary systems involving ILs have also been performed to demonstrate the validity of the parameterization of COSMO-RS model for ILs.The results showed that the predicted results by COSMO-RS model with the new optimized parameters are in much better agreement with experimental data than those by the original versions over a wide temperature and pressure range.The COSMO-RS model for ILs presented in this work improves the prediction accuracy of thermodynamic properties for the systems containing ILs,which is always highly desirable for general chemical engineers.展开更多
Suitable control of the humidity can contribute to electric energy savings. However, the present dehumidification system has many weak points. The liquid desiccant air-conditioning system has recently gained growing i...Suitable control of the humidity can contribute to electric energy savings. However, the present dehumidification system has many weak points. The liquid desiccant air-conditioning system has recently gained growing interest from the stand point of reducing energy consumption during dehumidification. In order to find the appropriate ionic liquids(ILs) as a desiccant for the liquid desiccant air-conditioner system, we conducted a systematic evaluation of the humidification capability of 16 types of ILs. Among the tested ILs, tributyl(methyl)phosphonium dimethyl phosphate([P4441][DMPO_4]) exhibited the best dehumidification capacity and had a less corrosive effect on four types of metals as possible piping materials. It should be noted that this [P_(4441)][DMPO_4] has a very stable nature and produced no odor while conducting the experiment and storing for over 1 year at room temperature under ambient conditions. Furthermore, it was revealed that a 77%(w/w) aqueous solution of [P4441][DMPO_4] worked as an efficient desiccant liquid for the liquid desiccant air-conditioner system.展开更多
Novozym-435 Lipase-catalyzed transesterification of glucose with 11-dodecenoic ethyl ester in ionic liquids was investigated. The effect of substrate ratio, lipase content, and temperature on the activity and stabilit...Novozym-435 Lipase-catalyzed transesterification of glucose with 11-dodecenoic ethyl ester in ionic liquids was investigated. The effect of substrate ratio, lipase content, and temperature on the activity and stability of lipase was also studied. The highest yield of sugar ester was obtained in 1-buty-3-methyl imidazolium tetrafluoroborate [Bmim][BF4] under such conditions as the reaction temperature of 55℃, the enzyme concentration of 20 mg/mL, the mole ratio of glucose/11-dodecenoic ethyl ester of 1:2, the water content of the system of 2%, Lipase Novozym-435 can use repeatedly 7 times. The structure of production was characterized by FTIR, HPLC, MS and NMR. The results show that the production is 6-O-(11-dodecenoic)-glucose ester.展开更多
In this work, three different aqueous solutions containing imidazole-based ILs w让h different alkyl chain lengths ([Cnmim]Br, n = 2Z 6,12) were adopted as the medium for the synthesis of ionic liquid-polypyrrole (IL-P...In this work, three different aqueous solutions containing imidazole-based ILs w让h different alkyl chain lengths ([Cnmim]Br, n = 2Z 6,12) were adopted as the medium for the synthesis of ionic liquid-polypyrrole (IL-PPy) composites. Herein, the ILs undertook the roles of the pyrrole solvent, the media for emulsion polymerization of PPy and PPy dopants, respectively. The electrochemical performances of the three IL-PPy composites on a glassy carbon electrode (GCE) were investigated by electrochemical experiments, which indicated that [Ci2mim]Br-PPy (Ci2~PPy) composites displayed better electrochemical performance due to their larger surface area and firmer immobilization on the GCE. Further, Ci2?PPy/GCE were decorated with Au microparticles by electrodeposition that can not only increase the conductivity, but also immobilize sufficient biomolecules on the electrode. Then, the obtained Ci2~PPy^Au/GCE with outstanding electrochemical performance was employed as a horseradish peroxidase (HRP) immobilization platform to fabricate a novel Ci2-PPy-Au-HRP/GCE biosensor for H2O2 detection. The results showed that the prepared Ci2-PPy-Au-HRP/GCE biosensor exhibited high sensitivity, fast response, and a wide detection range as well as low detection limit towards H2O2. This work not only provides an outstanding biomolecule immobilization matrix for the fabrication of highly sensitive biosensors, but also advances the understanding of the roles of ILs in improving the electrochemical performance of biosensors.展开更多
In this work, a new microextraction method termed ionic liquid based dispersive liquid-liquid microextraction (IL-DLLME) was demonstrated for the extraction of 2-methylaniline, 4-chloroaniline, 1-naphthylamine and 4...In this work, a new microextraction method termed ionic liquid based dispersive liquid-liquid microextraction (IL-DLLME) was demonstrated for the extraction of 2-methylaniline, 4-chloroaniline, 1-naphthylamine and 4-aminobiphenyl in aqueous matrices. After extraction the ionic liquid (IL) phase was injected directly into the high performance liquid chromatography (HPLC) system for determination. Some parameters that might affect the extraction efficiency were optimized. Under the optimum conditions, good linear relationship, sensitivity and reproducibility were obtained. The limits of detection (LOD, S/N = 3) for the four analytes were in the range of 0.45-2.6 μg L^-1. The relative standard deviations (R.S.D., n = 6) were in the range of 6.2-9.8%. This method was applied for the analysis of the real water samples. The recoveries ranged from 93.4 to 106.4%. The main advantages of the method are high speed, high recovery, good repeatability and volatile organic solvent-free.展开更多
This work proposed to use the ionic liquid [EMIM][BF_4] as absorbent for the absorption of gaseous acetic acid. The feasibility of this technology was investigated from molecular level to industrial scale. The acetic ...This work proposed to use the ionic liquid [EMIM][BF_4] as absorbent for the absorption of gaseous acetic acid. The feasibility of this technology was investigated from molecular level to industrial scale. The acetic acid absorption experiment was carried out using [EMIM][BF_4],and the removal ratio of acetic acid in the gas product can achieve 88.6% at 20C under atmospheric pressure at the laboratory scale. Based on the experimental results, a reliable strict equilibrium phase model embedding the parameters of the UNIFAC model was established. On this basis, the conceptual process design and optimization of acetic acid removal by [EMIM][BF_4] at an industrial scale was done, and the most suitable design and operation parameters were obtained. For a further step, the binding energy between [EMIM][BF_4] and acetic acid was calculated to give some insights into the separation mechanism, and the results indicate that the interaction between acetic acid and IL is much stronger than that between nitrogen and IL. Moreover, hydrogen bond can be formed between the cation-acetic acid as well as the anion-acetic acid.展开更多
A suitable ionic liquid for methyl chloride drying experiment was screened out from 210 ionic liquids by COSMO-RS model.Moreover,the experimental mechanism of ionic liquids drying is further explained by the COSMO-RS ...A suitable ionic liquid for methyl chloride drying experiment was screened out from 210 ionic liquids by COSMO-RS model.Moreover,the experimental mechanism of ionic liquids drying is further explained by the COSMO-RS model,and it is further confirmed by analyzing the binding energy.The solubility of methyl chloride in[EMIM][BF4]and TEG and[EMIM][BF4]+H2O was completed,and the experimental results well proved the reliability of the UNIFAC-Lei model.The unknown interaction parameters were obtained through the solubility data of this work and the experimental data in the literatures.The methyl chloride drying experiment was completed in the laboratory,and the water content of the methyl chloride can be reduced to below 200 ppm.The simulation of the methyl chloride drying process using[EMIM][BF4]or TEG as absorbents was carried out by ASPEN software on an industrial scale.The final simulation results show that the[EMIM][BF4]drying process has lower energy consumption and better drying effect.展开更多
This paper describes a new approach for the determination of amitriptyline in wastewater by ionic liquid based immersed droplet microextraction (IL-IDME) prior to highperformance liquid chromatography with ultraviol...This paper describes a new approach for the determination of amitriptyline in wastewater by ionic liquid based immersed droplet microextraction (IL-IDME) prior to highperformance liquid chromatography with ultraviolet detection. 1-Hexyl-3-methylimidazolium hexafluorophosphate ([C6MIM][PF6]) was used as an ionic liquid. Various factors that affect extraction, such as volume of ionic liquid, stirring rate, extraction time, pH of the aqueous solution and salting effect, were optimized. The optimal conditions were as follows: microextraction time, 10 min; stirring rate, 720 rpm; pH, 11; ionic drop volume, 100 uL; and no sodium chloride addition. In quantitative experiments the method showed linearity in a range from 0.01 to 10 ug/mL, a limit of detection of 0.004 ug/mL and an excellent pre-concentration factor (PF) of 1100. Finally, the method was successfully applied to the determination of amitriptyline in the hospital wastewater samples.展开更多
Ionic liquids(ILs)have been used effectively in many applications for reducing problems related to friction and wear.In this work,the potential of ILs as an anti-wear and extreme pressure lubricant additive for high l...Ionic liquids(ILs)have been used effectively in many applications for reducing problems related to friction and wear.In this work,the potential of ILs as an anti-wear and extreme pressure lubricant additive for high load-carrying gearbox applications such as helicopter transmissions has been studied.Two halide-free ILs:P_(8881)(BuO)_(2)PO_(2)^(-)(1)and P_(8881)(MeO)_(2)PO_(2)^(-)(2),which are blended at 5 wt%each into a standard non-additivated FVA2 base oil(BO)are examined.Their solid-liquid interface,friction and load-carrying capacity,and wear(scuffing)behavior are studied on the nano-,lab-,and component-scale,respectively,at a different range of temperature and loading conditions by using the atomic force microscopy(AFM),Schwing-Reib-Verschleiβ(SRV)friction tests,and Brugger tests,as well as forschungsstelle für zahnrader und getriebebau(FZG)back-to-back gear test rig.The AFM analysis shows nearly no change of adhesion over the full range of studied temperature for the IL blends compared to the BO.Similarly,IL blends demonstrate a very stable coefficient of friction(COF)of around 0.16,which even decreases with increasing test temperatures ranging from 40 to 120℃.A clear reduction in COF up to 25%is achieved by adding only 5 wt%of the investigated Ils in the BO,and the Brugger tests also show a pronounced enhancement of load-carrying capacity.Finally,on the component-scale,a significant improvement in gear scuffing performance has been observed for both used IL blends.A detailed characterization of the wear tracks from the SRV friction tests via the transmission electron microscopy(TEM)revealed the formation of a phosphate(P-O)-based amorphous tribo-chemical layer of about 20 nm thickness.Therefore,this work may present an approach for Ils to be used as an additive in conventional lubricants due to their ability to enhance the lubrication properties,making them an alternative lubricant solution for high load-carrying gearbox applications.展开更多
This study investigated the prospect of using aqueous mixture of 1-butylpyridinium tetrafluoroborate ([Bpy][BF4]) ionic liquid (IL) and monoethanolamine (MEA) as solvent in post-combustion CO2 capture (PCC) pr...This study investigated the prospect of using aqueous mixture of 1-butylpyridinium tetrafluoroborate ([Bpy][BF4]) ionic liquid (IL) and monoethanolamine (MEA) as solvent in post-combustion CO2 capture (PCC) process. This is done by analysis of the process through modelling and simulation. In literature, reported PCC models with a mixture of IL and MEA solvent were developed using equilibrium-based mass transfer approach. In contrast, the model in this study is developed using rate-based mass transfer approach in Aspen Plus. From the results, the mixed aqueous solvent with 5-30 wt% IL and 30 wt% MEA showed 7%-9% and 12%-27% less specific regeneration energy and solvent circulation rate respectively compared to commonly used 30 wt% MEA solvent. It is concluded that the |L concentration (wt%) in the solvent blend have significant impact on specific regeneration energy and solvent circulation rate. This study is a starting point for further research on technical and economic analysis of PCC process with aqueous blend of IL and MEA as solvent.展开更多
Cyclic voltammetry based on an electrochemical technique is one of the current methods that measure the developments of the electrochemical properties in biomaterial samples under conditions. Biomaterial structure was...Cyclic voltammetry based on an electrochemical technique is one of the current methods that measure the developments of the electrochemical properties in biomaterial samples under conditions. Biomaterial structure was changed by conductive material while these materials caused a connective network in whole of them and was able to transfer electrons inside of biomaterials. These changes in physical and chemical properties are investigated by analysis tools such as cyclic voltammetry (CV), X-radiation (XRF) and Ultraviolet-visible spectroscopy (UV-Vis). Bacterial cellulose is biodegradable, biosynthesis of A. xylinum which is a three-dimensional nano-network structure with a distinct tunnel and pore structure. In this study, the composite process produced electrically conducting bacterial cellulose pellicles containing well-dispersed and embedded multi-walled carbon nanotubes (MWCNTs) Ionic liquids (ILs), as observed in cyclic voltammetry (CV). For this purpose, we used a special tool, called OriginLab which is an industry-leading scientific graphing and data analysis software. The cyclic voltammetry graph presents the behavior of this composite which consists of a relationship between CNT dispersion, conductivity rate and changes in bacterial cellulose structure. The electrical conductivity of the cellulose/MWCNT composite was found different with respect to CNT dispersion. It was found that the incorporation process was a useful method not only for dispersing MWCNTs-ILs in an ultrafine fibrous network structure, but also for enhancing the electrical conductivity of the polymeric membranes.展开更多
基金supported by the National Key Research and Development Program of China(2021YFB3802600)the National Natural Science Foundation of China(22278396,22378392,22178344)+1 种基金the Youth Innovation Promotion Association CAS(Y2021022)the Open Research Fund of State Key Laboratory of Mesoscience and Engineering(MESO-23-D17)。
文摘Ionic liquids(ILs)are an emerging class of media of fundamental importance for chemical engineering,especially due to their interaction with solid surfaces.Here,we explore the growth phenomenon of surface-confined ILs and reveal a peculiar structural transition behavior from order to disorder above a threshold thickness.This behavior can be explained by the variation of interfacial forces with increasing distance from the solid surface.Direct structural observation of different ILs highlights the influence of the ionic structure on the growth process.Notably,the length of the alkyl chain in the cation is found to be a determining factor for the ordering trend.Also,the thermal stability of surface-confined ILs is investigated in depth by controlling annealing treatments.It is found that the ordered monolayer ILs exhibit high robustness against high temperatures.Our findings provide new perspectives on the properties of surface-confined ILs and open up potential avenues for manipulating the structures of nanometer-thick IL films for various applications.
基金We thank the financial support from the National Natural Science Foundation of China.(No.20172038)
文摘Benzoin condensation promoted efficiently in three imidazolium based room tempera- ture ionic liquids [bmim]Br, [bmim]BF4 and [Bnmim]BF4 is reported for the first time. Benzoins were obtained in up to 91% yield within less than 30 min under mild conditions.
文摘The fluorination reaction involving a β-ketosulfones by Selectfluor^TM was efficiently promoted by the ionic liquid, [Hbim]BF4 (IL) as a reaction medium with methanol as co-solvent at room temperature under ultrasonic irradiation to afford the corresponding mono and difluoro-β-ketosulfones in excellent yields. The advantages of this method include among others the use of a recyclable, non-volatile ionic liquid, which promotes this protocol under room temperature without the requirement of any added catalyst under ultrasonic irradiation.
基金supported by the Natural Science Foundation of Fujian Province,China(2021J01641)National Natural Science Foundation of China(21706062)the Scientific Research Starting Foundation of Fuzhou University,China(GXRC-18073)。
文摘Economically separating 1-propanol(NPA)from water is an emergent issue for producing pharmaceutical intermediates such as n-propyl acetate,n-propylamine and so on.In this work,fourionic liquids(ILs)1-ethyl-3-methylimidazolium thiocyanate([EMIM][SCN]),1-butyl-3-methylimidazolium tetrafluoroborate([BMIM][BF_(4)]),1,3-dimethylimidazolium methylsulfate([MMIM][MS]),1,3-dimethylimidazolium dimethylphosphate([MMIM][DMP])were introduced as potential entrainers for separating NPA–water azeotropic mixture.The results show that[MMIM][MS]is the most suitable entrainer compared with other ILs from the analysis of vapor-liquid equilibrium and relative volatilities.The extractive distillation process with the entrainer regeneration system of flash tank and stripper was employed and optimized by the two-step optimization method.The results show that total annual cost and energy consumption per product flow rate were reduced by 39.79%and 60.47%compared with literature.In addition,the efficiency indicator of extractive section,efficiency indicator of per tray in extractive section,carbon dioxide emissions were also selected as the evaluation index for selection of operating parameters and calculated for different cases.The CO_(2)emissions of the optimal design can be reduced by 60.98%from environmental aspect.
文摘The controllable molecular weight and polydispersity of polyacrylonitriles(PANs) were synthesized in ionic liquids(ILs) by atom transfer radical polymerization(ATRP) using ethyl-2 bromopropionate(EPN-Br) as initiator and CuBr/pentamethyldiethylenetria-mine(PMDETA) as catalyst.The polydispersity index(PDI) in the ATRP of acrylonitriel(AN) in ILs is lower than 1.3.From the polymerization kinetics,plots of ln([M]0/[M]) with time show a linear dependence at the early stage of polymerization while the deviation is observed with the conversion rate increasing.The polymerization rate in ILs,especially in 1-butyl-3-methylimidazolium chloride([bmim]Cl),is higher than that in N,N-dimethylformamide(DMF).The polymerization rate increased and the average molecular weight decreased with temperature increasing.The polymerization rate,molecular weight and PDI varied with the variation of [AN]0:[EPN-Br]0:[CuBr]0:[PMDETA]0 ratio in the experimental range,the polymerization of AN in [bmim]Cl displayed living polymerization characteristics.Moreover,the catalyst and ILs are easily isolated from the polymer and reused.
基金financially supported by the National Natural Science Foundation of China under Grants (Nos. 21476009, 21406007 and U1462104)
文摘The adjustable parameters in the popular conductor-like screening model for real solvents(COSMO-RS)within the Amsterdam density functional(ADF)framework have been re-optimized to fit for the systems containing ionic liquids(ILs).To get the optimal values of misfit energy constant a^0,hydrogen bond coefficient c_(hb)and effective contact surface area of a segment a_(eff),2283 activity coefficient data points at infinite dilution and 1433 CO_2 solubility data points exhaustively collected from references were used as training set.The average relative deviations(ARDs)of activity coefficients at infinite dilution and CO_2 solubility between experimental data and predicted values are 32.22%and17.61%,respectively,both of which are significantly lower than the original COSMO-RS versions.Predictions for other activity coefficients of solutes in ILs,solubility data of CO_2 in pure ILs and the binary mixtures of ILs at either high or low temperatures,and vapor–liquid equilibrium(VLE)for binary systems involving ILs have also been performed to demonstrate the validity of the parameterization of COSMO-RS model for ILs.The results showed that the predicted results by COSMO-RS model with the new optimized parameters are in much better agreement with experimental data than those by the original versions over a wide temperature and pressure range.The COSMO-RS model for ILs presented in this work improves the prediction accuracy of thermodynamic properties for the systems containing ILs,which is always highly desirable for general chemical engineers.
基金supported by a fund for environmental research from Tottori University
文摘Suitable control of the humidity can contribute to electric energy savings. However, the present dehumidification system has many weak points. The liquid desiccant air-conditioning system has recently gained growing interest from the stand point of reducing energy consumption during dehumidification. In order to find the appropriate ionic liquids(ILs) as a desiccant for the liquid desiccant air-conditioner system, we conducted a systematic evaluation of the humidification capability of 16 types of ILs. Among the tested ILs, tributyl(methyl)phosphonium dimethyl phosphate([P4441][DMPO_4]) exhibited the best dehumidification capacity and had a less corrosive effect on four types of metals as possible piping materials. It should be noted that this [P_(4441)][DMPO_4] has a very stable nature and produced no odor while conducting the experiment and storing for over 1 year at room temperature under ambient conditions. Furthermore, it was revealed that a 77%(w/w) aqueous solution of [P4441][DMPO_4] worked as an efficient desiccant liquid for the liquid desiccant air-conditioner system.
文摘Novozym-435 Lipase-catalyzed transesterification of glucose with 11-dodecenoic ethyl ester in ionic liquids was investigated. The effect of substrate ratio, lipase content, and temperature on the activity and stability of lipase was also studied. The highest yield of sugar ester was obtained in 1-buty-3-methyl imidazolium tetrafluoroborate [Bmim][BF4] under such conditions as the reaction temperature of 55℃, the enzyme concentration of 20 mg/mL, the mole ratio of glucose/11-dodecenoic ethyl ester of 1:2, the water content of the system of 2%, Lipase Novozym-435 can use repeatedly 7 times. The structure of production was characterized by FTIR, HPLC, MS and NMR. The results show that the production is 6-O-(11-dodecenoic)-glucose ester.
基金the National Natural Science Foundation of China(Project No.21476072)the Fundamental Research Funds for the Central Universities.
文摘In this work, three different aqueous solutions containing imidazole-based ILs w让h different alkyl chain lengths ([Cnmim]Br, n = 2Z 6,12) were adopted as the medium for the synthesis of ionic liquid-polypyrrole (IL-PPy) composites. Herein, the ILs undertook the roles of the pyrrole solvent, the media for emulsion polymerization of PPy and PPy dopants, respectively. The electrochemical performances of the three IL-PPy composites on a glassy carbon electrode (GCE) were investigated by electrochemical experiments, which indicated that [Ci2mim]Br-PPy (Ci2~PPy) composites displayed better electrochemical performance due to their larger surface area and firmer immobilization on the GCE. Further, Ci2?PPy/GCE were decorated with Au microparticles by electrodeposition that can not only increase the conductivity, but also immobilize sufficient biomolecules on the electrode. Then, the obtained Ci2~PPy^Au/GCE with outstanding electrochemical performance was employed as a horseradish peroxidase (HRP) immobilization platform to fabricate a novel Ci2-PPy-Au-HRP/GCE biosensor for H2O2 detection. The results showed that the prepared Ci2-PPy-Au-HRP/GCE biosensor exhibited high sensitivity, fast response, and a wide detection range as well as low detection limit towards H2O2. This work not only provides an outstanding biomolecule immobilization matrix for the fabrication of highly sensitive biosensors, but also advances the understanding of the roles of ILs in improving the electrochemical performance of biosensors.
基金the National Natural Science Foundation of China(Nos.20375035,20527005,20775070)by Zhejiang Provincial Natural Science Foundation of China(Nos.Z404105,Y507252).
文摘In this work, a new microextraction method termed ionic liquid based dispersive liquid-liquid microextraction (IL-DLLME) was demonstrated for the extraction of 2-methylaniline, 4-chloroaniline, 1-naphthylamine and 4-aminobiphenyl in aqueous matrices. After extraction the ionic liquid (IL) phase was injected directly into the high performance liquid chromatography (HPLC) system for determination. Some parameters that might affect the extraction efficiency were optimized. Under the optimum conditions, good linear relationship, sensitivity and reproducibility were obtained. The limits of detection (LOD, S/N = 3) for the four analytes were in the range of 0.45-2.6 μg L^-1. The relative standard deviations (R.S.D., n = 6) were in the range of 6.2-9.8%. This method was applied for the analysis of the real water samples. The recoveries ranged from 93.4 to 106.4%. The main advantages of the method are high speed, high recovery, good repeatability and volatile organic solvent-free.
基金financially supported by the National Natural Science Foundation of China(No.U1862103)
文摘This work proposed to use the ionic liquid [EMIM][BF_4] as absorbent for the absorption of gaseous acetic acid. The feasibility of this technology was investigated from molecular level to industrial scale. The acetic acid absorption experiment was carried out using [EMIM][BF_4],and the removal ratio of acetic acid in the gas product can achieve 88.6% at 20C under atmospheric pressure at the laboratory scale. Based on the experimental results, a reliable strict equilibrium phase model embedding the parameters of the UNIFAC model was established. On this basis, the conceptual process design and optimization of acetic acid removal by [EMIM][BF_4] at an industrial scale was done, and the most suitable design and operation parameters were obtained. For a further step, the binding energy between [EMIM][BF_4] and acetic acid was calculated to give some insights into the separation mechanism, and the results indicate that the interaction between acetic acid and IL is much stronger than that between nitrogen and IL. Moreover, hydrogen bond can be formed between the cation-acetic acid as well as the anion-acetic acid.
基金financially supported by the National Natural Science Foundation of China(No.U1862103)and(No.21961160740)
文摘A suitable ionic liquid for methyl chloride drying experiment was screened out from 210 ionic liquids by COSMO-RS model.Moreover,the experimental mechanism of ionic liquids drying is further explained by the COSMO-RS model,and it is further confirmed by analyzing the binding energy.The solubility of methyl chloride in[EMIM][BF4]and TEG and[EMIM][BF4]+H2O was completed,and the experimental results well proved the reliability of the UNIFAC-Lei model.The unknown interaction parameters were obtained through the solubility data of this work and the experimental data in the literatures.The methyl chloride drying experiment was completed in the laboratory,and the water content of the methyl chloride can be reduced to below 200 ppm.The simulation of the methyl chloride drying process using[EMIM][BF4]or TEG as absorbents was carried out by ASPEN software on an industrial scale.The final simulation results show that the[EMIM][BF4]drying process has lower energy consumption and better drying effect.
文摘This paper describes a new approach for the determination of amitriptyline in wastewater by ionic liquid based immersed droplet microextraction (IL-IDME) prior to highperformance liquid chromatography with ultraviolet detection. 1-Hexyl-3-methylimidazolium hexafluorophosphate ([C6MIM][PF6]) was used as an ionic liquid. Various factors that affect extraction, such as volume of ionic liquid, stirring rate, extraction time, pH of the aqueous solution and salting effect, were optimized. The optimal conditions were as follows: microextraction time, 10 min; stirring rate, 720 rpm; pH, 11; ionic drop volume, 100 uL; and no sodium chloride addition. In quantitative experiments the method showed linearity in a range from 0.01 to 10 ug/mL, a limit of detection of 0.004 ug/mL and an excellent pre-concentration factor (PF) of 1100. Finally, the method was successfully applied to the determination of amitriptyline in the hospital wastewater samples.
基金funded by the Endowed Professorship on“Tribology”at the Vienna University of Technology(Grant No.WST3-F-5031370/001-2017).
文摘Ionic liquids(ILs)have been used effectively in many applications for reducing problems related to friction and wear.In this work,the potential of ILs as an anti-wear and extreme pressure lubricant additive for high load-carrying gearbox applications such as helicopter transmissions has been studied.Two halide-free ILs:P_(8881)(BuO)_(2)PO_(2)^(-)(1)and P_(8881)(MeO)_(2)PO_(2)^(-)(2),which are blended at 5 wt%each into a standard non-additivated FVA2 base oil(BO)are examined.Their solid-liquid interface,friction and load-carrying capacity,and wear(scuffing)behavior are studied on the nano-,lab-,and component-scale,respectively,at a different range of temperature and loading conditions by using the atomic force microscopy(AFM),Schwing-Reib-Verschleiβ(SRV)friction tests,and Brugger tests,as well as forschungsstelle für zahnrader und getriebebau(FZG)back-to-back gear test rig.The AFM analysis shows nearly no change of adhesion over the full range of studied temperature for the IL blends compared to the BO.Similarly,IL blends demonstrate a very stable coefficient of friction(COF)of around 0.16,which even decreases with increasing test temperatures ranging from 40 to 120℃.A clear reduction in COF up to 25%is achieved by adding only 5 wt%of the investigated Ils in the BO,and the Brugger tests also show a pronounced enhancement of load-carrying capacity.Finally,on the component-scale,a significant improvement in gear scuffing performance has been observed for both used IL blends.A detailed characterization of the wear tracks from the SRV friction tests via the transmission electron microscopy(TEM)revealed the formation of a phosphate(P-O)-based amorphous tribo-chemical layer of about 20 nm thickness.Therefore,this work may present an approach for Ils to be used as an additive in conventional lubricants due to their ability to enhance the lubrication properties,making them an alternative lubricant solution for high load-carrying gearbox applications.
文摘This study investigated the prospect of using aqueous mixture of 1-butylpyridinium tetrafluoroborate ([Bpy][BF4]) ionic liquid (IL) and monoethanolamine (MEA) as solvent in post-combustion CO2 capture (PCC) process. This is done by analysis of the process through modelling and simulation. In literature, reported PCC models with a mixture of IL and MEA solvent were developed using equilibrium-based mass transfer approach. In contrast, the model in this study is developed using rate-based mass transfer approach in Aspen Plus. From the results, the mixed aqueous solvent with 5-30 wt% IL and 30 wt% MEA showed 7%-9% and 12%-27% less specific regeneration energy and solvent circulation rate respectively compared to commonly used 30 wt% MEA solvent. It is concluded that the |L concentration (wt%) in the solvent blend have significant impact on specific regeneration energy and solvent circulation rate. This study is a starting point for further research on technical and economic analysis of PCC process with aqueous blend of IL and MEA as solvent.
文摘Cyclic voltammetry based on an electrochemical technique is one of the current methods that measure the developments of the electrochemical properties in biomaterial samples under conditions. Biomaterial structure was changed by conductive material while these materials caused a connective network in whole of them and was able to transfer electrons inside of biomaterials. These changes in physical and chemical properties are investigated by analysis tools such as cyclic voltammetry (CV), X-radiation (XRF) and Ultraviolet-visible spectroscopy (UV-Vis). Bacterial cellulose is biodegradable, biosynthesis of A. xylinum which is a three-dimensional nano-network structure with a distinct tunnel and pore structure. In this study, the composite process produced electrically conducting bacterial cellulose pellicles containing well-dispersed and embedded multi-walled carbon nanotubes (MWCNTs) Ionic liquids (ILs), as observed in cyclic voltammetry (CV). For this purpose, we used a special tool, called OriginLab which is an industry-leading scientific graphing and data analysis software. The cyclic voltammetry graph presents the behavior of this composite which consists of a relationship between CNT dispersion, conductivity rate and changes in bacterial cellulose structure. The electrical conductivity of the cellulose/MWCNT composite was found different with respect to CNT dispersion. It was found that the incorporation process was a useful method not only for dispersing MWCNTs-ILs in an ultrafine fibrous network structure, but also for enhancing the electrical conductivity of the polymeric membranes.