scholarly journals Recycling of 1,2-Dimethyl-3-propylimidazolium bis(trifluoromethylsulfonyl)imide Ionic Liquid by Stacked Cation and Anion Exchange Adsorption-Desorption

Separations ◽  
2019 ◽  
Vol 6 (2) ◽  
pp. 29
Author(s):  
Cynthia A. Corley ◽  
Scott T. Iacono
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Ion Exchange ◽  
Anion Exchange ◽  
Membrane Separation ◽  
Ion Pairs ◽  
Exchange Adsorption ◽  
Adsorption Desorption ◽  
Desorption Method

There are many advantages to using ionic liquids as solvents or catalysts in chemical processes. Their non-volatile characteristic and high cost, however, can pose economic, environmental, and long-term health concerns. As such, the recovery and recycling of ionic liquids have become essential to mitigate their environmental impact and to reduce costs. Numerous recovery and recycling methods have been reported, including distillation, extraction, membrane separation (a.k.a. filtration), adsorption, crystallization, gravity, and electrochemical separation. Whereas most of these methods recover both cations and anions of the ionic liquid as ion pairs, recycling methods such as single-phase ion exchange or mixed-ion exchange/non-ionic adsorption methods recover only one of the ionic liquid ions, typically the cation. These methods are frequently used for the recycling of ionic liquids having simple anions such as chloride or acetate, but are seldom employed for ionic liquids consisting of larger and more complex anions due to the added time and reagent costs necessary for the regeneration of the original ionic liquid. Herein, a combined cation and anion exchange adsorption-desorption method is presented that can effectively separate 1,2-dimethyl-3-propylimidazolium bis(trifluoromethylsulfonimide) [DMPIm][NTf2] ionic liquid from neutral impurities. More importantly, the method is capable of recovery and recycling of the original ionic liquid. Concomitant desorption of both ionic liquid ions was achieved using 0.1 M NaCl: methanol (90:10 v/v) eluent followed by isolation using liquid–liquid extraction to afford high purity products and yields of approximately 60%.

Dynamics of Ion Locking in Doubly Polymerized Ionic Liquids

2020 ◽  
Author(s):  
Swati Arora ◽  
Julisa Rozon ◽  
Jennifer Laaser
Keyword(s):  
Dielectric Constant ◽  
Ionic Liquid ◽  
Ionic Liquids ◽  
Ion Pairs ◽  
Polymer Chains ◽  
Ion Motion ◽  
Charged Species ◽  
Broadband Dielectric Spectroscopy ◽  
Covalently Linked ◽  
Insight Into

<div>In this work, we investigate the dynamics of ion motion in “doubly-polymerized” ionic liquids (DPILs) in which both charged species of an ionic liquid are covalently linked to the same polymer chains. Broadband dielectric spectroscopy is used to characterize these materials over a broad frequency and temperature range, and their behavior is compared to that of conventional “singly-polymerized” ionic liquids (SPILs) in which only one of the charged species is attached to the polymer chains. Polymerization of the DPIL decreases the bulk ionic conductivity by four orders of magnitude relative to both SPILs. The timescales for local ionic rearrangement are similarly found to be approximately four orders of magnitude slower in the DPILs than in the SPILs, and the DPILs also have a lower static dielectric constant. These results suggest that copolymerization of the ionic monomers affects ion motion on both the bulk and the local scales, with ion pairs serving to form strong physical crosslinks between the polymer chains. This study provides quantitative insight into the energetics and timescales of ion motion that drive the phenomenon of “ion locking” currently under investigation for new classes of organic electronics.</div>

scholarly journals Zinc Acetate Immobilized on Mesoporous Materials by Acetate Ionic Liquids as Catalysts for Vinyl Acetate Synthesis

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Hang Xu ◽  
Tianlong Yu ◽  
Mei Li
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Vinyl Acetate ◽  
Silica Gel ◽  
Catalyst Activity ◽  
Catalyst Layer ◽  
Space Velocity ◽  
Molar Ratio ◽  
Vinyl Acetate Monomer ◽  
Adsorption Desorption

Ionic liquid containing active ingredient Zn(CH3COO)2was loaded in mesoporous silica gel to form supported ionic liquids catalyst (SILC) which was used to synthesize vinyl acetate monomer (VAM). SILC was characterized by1HNMR, FT-IR, TGA, BET, and N2adsorption/desorption and the acetylene method was used to evaluate SILC catalytic activity and stability in fixed reactor. The result shows that 1-allyl-3-acetic ether imidazole acetate ionic liquid is successfully fixed within mesoporous channel of silica gel. The average thickness of ionic liquid catalyst layer is about 1.05 nm. When the catalytic temperature is 195°C, the acetic acid (HAc) conversion is 10.9% with 1.1 g vinyl acetate yield and 98% vinyl acetate (VAc) selectivity. The HAc conversion is increased by rise of catalytic temperature and molar ratio of C2H2 : HAc and decreased by mass space velocity (WHSV). The catalyst activity is not significantly reduced within 7 days and VAc selectivity has a slight decrease.

Density Functional Theory Study on the Absorption of CO2 by the Ionic Liquid of 1-butyl-3-methylimidazolium Acetate

2013 ◽  
Vol 807-809 ◽  
pp. 543-548 ◽  
Author(s):  
Yan Fei Chen ◽  
Yan Hong Cui ◽  
Dong Shun Deng ◽  
Ning Ai
Keyword(s):  
Density Functional Theory ◽  
Ionic Liquid ◽  
Ionic Liquids ◽  
Density Functional ◽  
Ion Pairs ◽  
Ion Pair ◽  
Frontier Molecular Orbitals ◽  
Density Functional Theory Study ◽  
Electronic Density ◽  
Functional Theory

The absorptions of CO2on the 1-butyl-3-methylimidazolium acetate ([Bmi [Ac]) with different substituents are calculated systematically at GGA/PW91 level. Three hydrogen bonds are formed between [A and cations of 1-n-[Bmi [A ([NBmi+) and 1-tert-[Bmi [A ([TBmi+). The interaction between CO2and the [NBmi [A by a C-O bond is much weaker than that with the [TBmi [A by forming a O...O...C...C four member-ring. The chemisorption of CO2on the ion pairs of [NBmi [A is much weaker than that on the [TBmi [A, resulted from the absorption energies analysis. The frontier molecular orbitals shows the electronic density overlap between absorbed CO2and the [A in CO2-[NBmi [A is much weaker than that in [TBmi [A. Therefore, the chemisorption of CO2on the ion pair of [NBmi [A is much weaker than that on the [TBmi [A. The ionic liquids based [NBmi+can be used repetitively, and the adsorbed CO2would be easier desorbed.

Effects of Ionic Liquid Blending in Polymeric Membrane: Physical Properties and Performance Evaluation

2014 ◽  
Vol 625 ◽  
pp. 680-684 ◽  
Author(s):  
Dzeti Farhah Mohshim ◽  
Hilmi Mukhtar ◽  
Zakaria Man
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Membrane Separation ◽  
Initial Study ◽  
Polymeric Membranes ◽  
Polymeric Membrane ◽  
Separation Performance ◽  
Operating Pressure ◽  
Membrane Gas Separation ◽  
Pes Membrane

— Polymeric membranes have been extensively used in membrane gas separation process. Nowadays, peoples are modifying the membrane by many ways like coating with ionic liquids to further enhance the membrane separation performance. In this project, ionic liquid modified polymeric membranes (ILMPM) have been successfully developed by blending the ionic liquids with the polymer via solvent evaporation method. The ionic liquid used was 1-ethyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide, ([emim][Tf2N]) and for comparison purpose, the compositions were varied at 10 and 20 wt/wt%. In general, the blending of [emim][Tf2N] and PES has produced dense membrane with miscible mixture without any phase separation. It was observed that, the CO2permeance of ILMPM has been improved about 271% as compared to the pure PES membrane. However, the CO2permeance decreased with increasing operating pressure, yet the ILMPM CO2permeance still higher than CO2permeance of pure PES membrane. In addition, the CO2/CH4separation performance has greatly increased about 162% as the IL composition is increased. This initial study has proven that IL helps to enhance of CO2permeation and improve selectivity.

Ionic Liquid [Bmim]OH Grafted Catalyst for Cycloaddition of Carbon Dioxide

2014 ◽  
Vol 989-994 ◽  
pp. 676-679 ◽  
Author(s):  
Xue Lan Zhang ◽  
Deng Feng Wang
Keyword(s):  
Carbon Dioxide ◽  
Ionic Liquid ◽  
Ionic Liquids ◽  
Silica Gel ◽  
Propylene Carbonate ◽  
Propylene Oxide ◽  
Heterogeneous Catalysts ◽  
Element Analysis ◽  
Mild Conditions ◽  
Adsorption Desorption

An ionic liquid 1-butyl-3-methylimidazolium hydroxide ([Bmim]OH) was grafted on silica gel by post-grafting method. Such grafted ionic liquids (GILs) which were verified by means of FTIR, element analysis N2adsorption-desorption and TG could be used as highly effective heterogeneous catalysts toward propylene carbonate synthesis through cycloaddition of carbon dioxide with propylene oxide under solventless and mild conditions.

Preparation and Activity of Ionic Liquid Catalysts Grafted on Hydrophobic Silica Gel

2012 ◽  
Vol 476-478 ◽  
pp. 2621-2624
Author(s):  
Xue Lan Zhang ◽  
Deng Feng Wang
Keyword(s):  
Carbon Dioxide ◽  
Ionic Liquid ◽  
Ionic Liquids ◽  
Silica Gel ◽  
Propylene Oxide ◽  
Heterogeneous Catalysts ◽  
N2 Adsorption ◽  
Mild Conditions ◽  
Hydrophobic Silica ◽  
Adsorption Desorption

An ionic liquid 1- (triethoxysilyl) propyl-3-methylimidazolium hydroxide ([Smim]OH) was grafted on three kinds of mesoporous hydrophobic silica gel by means of post-grafting under mild conditions. The catalysts were [Smim]OH/SiO2-MTES (methyltriethoxysilane), [Smim]OH/SiO2-TMCS (trimethylchlorosilane), [Smim]OH/SiO2-CPTEO (triethoxysilyl propyl chloride). Such grafted ionic liquids (GILs), which were characterized by means of FTIR and N2 adsorption-desorption could be used as effective heterogeneous catalysts toward propylene carbonate synthesis through cycloaddition of carbon dioxide with propylene oxide under solventless and mild conditions.

A new method for improving the ion conductivity of anion exchange membranes by using TiO2 nanoparticles coated with ionic liquid

RSC Advances ◽  
2016 ◽  
Vol 6 (99) ◽  
pp. 96768-96777 ◽  
Author(s):  
Yuhao Chu ◽  
Yuenan Chen ◽  
Nanjun Chen ◽  
Fanghui Wang ◽  
Hong Zhu
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Tio2 Nanoparticles ◽  
Anion Exchange ◽  
Ion Conductivity ◽  
New Method ◽  
Anion Exchange Membranes ◽  
The Novel ◽  
Novel Materials

Recently a new method for increasing the ion conductivity of anion exchange membranes (AEM) was developed based on the novel materials ionic liquids (ILs).

Hypercrosslinked mesoporous poly(ionic liquid)s with high density of ion pairs: Efficient adsorbents for Cr(VI) removal via ion-exchange

2019 ◽  
Vol 378 ◽  
pp. 122107 ◽  
Author(s):  
Yaqiang Xie ◽  
Ju Lin ◽  
Jun Liang ◽  
Minghong Li ◽  
Yawen Fu ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Ion Exchange ◽  
Ion Pairs ◽  
High Density ◽  
Poly Ionic Liquid

Synthesis of Imidazole Ionic Liquid and its Intercalation for Sodium Montmorillonite

2014 ◽  
Vol 528 ◽  
pp. 181-184 ◽  
Author(s):  
Su Jun Li ◽  
Shi Yang Bai
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Ion Exchange ◽  
Exchange Reaction ◽  
Sodium Montmorillonite ◽  
Chemical Structures ◽  
Ion Exchange Reaction ◽  
Carbon Chains

This paper synthesized three kinds of ionic liquids, there are [C14EIM]Br, [C16EIM]Br and [C18EIM]Br respectively. Then use the FTIR to characterize of chemical structures. Also study the effect of ionic liquids with different length of carbon chains to intercalated sodium montmorillonite. The results shown that the ionic liquids synthesized were the target products. The result of XRD shown that the ion exchange reaction between ionic liquid and the sodium montmorillonite could occurred, and the more numbers of carbon atoms of the ionic liquid, the longer the chain, the greater the distance of montmorillomote.

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