Molecular dynamics study of mesophase transitions upon annealing of imidazolium-based ionic liquids with long-alkyl chains

2018 ◽  
Vol 20 (15) ◽  
pp. 9796-9805 ◽  
Author(s):  
Hailong Peng ◽  
Momoji Kubo ◽  
Hayato Shiba

The isotropic to mesophase transition upon the long-time annealing of a 1-dodecyl-3-methylimidazolium hexafluorophosphate ionic liquid at different temperatures is illustrated.

2021 ◽  
Vol 23 (6) ◽  
Author(s):  
M. Meischein ◽  
A. Ludwig

AbstractUpscaling of nanoparticle fabrication by sputtering into an ionic liquid is shown for the example of Cu. Long-time sputtering (24 h) into a large amount (50 mL) of the ionic liquid 1-butyl-3-methylimidazolium bis-(trifluoromethylsulfonyl)imide [Bmim][(Tf)2 N] yields an amount of approximately 1 g Cu nanoparticles (mean spherical diameter (2.6 ± 1.1) nm), stabilized in ionic liquid without agglomerations. Extraction of Cu nanoparticles from the stabilizing ionic liquid was performed with the capping agent hexadecylamine. Extracted particles could be redispersed in other solvents, thus enabling applications of sputtered nanoparticles beyond ionic liquids.


2021 ◽  
Vol 874 ◽  
pp. 88-95
Author(s):  
Oktavianus Hendra Cipta ◽  
Anita Alni ◽  
Rukman Hertadi

The structure of Candida rugosa lipase can be affected by solvents used in the enzymatic reactions. Using molecular dynamics simulation as a tool to study the Candida rugosa lipase structure, we studied the effect of various solvent systems, such as water, water-methanol, and water-methanol-ionic liquid. These solvent systems have been chosen because lipase is able to function in both aqueous and non-aqueous medium. In this study, pyridinium (Py)-based ionic liquids were selected as co-solvent. The MD simulation was run for 50 nanoseconds for each solvent system at 328 K. In the case of water-methanol-ionic liquids solvent systems, the total number of the ionic liquids added were varied: 222, 444, and 888 molecules. Water was used as the reference solvent system. The structure of Candida rugosa lipase in water-methanol system significantly changed from the initial structure as indicated by the RMSD value, which was about 6.4 Å after 50 ns simulation. This value was relatively higher compared to the other water-methanol solvent system containing ionic liquid as co-solvent, which were 2.43 Å for 4Py-Br, 2.1 Å for 8Py-Br, 3.37 Å for 4Py-BF4 and 3.49 Å for 8Py-BF4 respectively. Further analysis by calculating the root mean square fluctuation (RMSF) of each lipase residue found that the presence of ionic liquids could reduce changes in the enzyme structure. This happened because the anion component of the ionic liquid interacts relatively more strongly with residues on the surface of the protein as compared to methanol, thereby lowering the possibility of methanol to come into contact with the protein.


2014 ◽  
Vol 16 (39) ◽  
pp. 21340-21348 ◽  
Author(s):  
Catarina M. S. S. Neves ◽  
Kiki A. Kurnia ◽  
Karina Shimizu ◽  
Isabel M. Marrucho ◽  
Luís Paulo N. Rebelo ◽  
...  

The presence of fluorinated alkyl chains in ionic liquids is quite relevant regarding their thermophysical properties and aqueous phase behaviour.


2017 ◽  
Vol 2017 ◽  
pp. 1-5 ◽  
Author(s):  
Hang Xu ◽  
Dandan Zhang

Viscosity and conductivity data of BMIMZnAcxCly(x=0,1,2,3;  y=3,2,1,0) ionic liquids were detected at temperature ranging from 323.15 to 353.15 K with an interval of 5 K. The conductivities of different ionic liquids at the same temperature followed the trend [BMIM][ZnAcCl2] > [BMIM][ZnAc2Cl] > [BMIM][ZnCl3] > [BMIM][ZnAc3]. The viscosities of different ionic liquid abided by the order [BMIM][ZnCl3] > [BMIM][ZnAcCl2] > [BMIM][ZnAc2Cl] > [BMIM][ZnAc3]. Acetate ion could reduce the viscosity of ionic liquids. The relationship between viscosity/conductivity and temperature obeyed the Arrhenius equation and Vogel-Fulcher-Tammann (VFT) equation very well with above 0.99 correlation coefficients.


2018 ◽  
Vol 20 (15) ◽  
pp. 10213-10223 ◽  
Author(s):  
Cesar Herrera ◽  
Mert Atilhan ◽  
Santiago Aparicio

Ionic liquid mixtures containing amino acid anions are studied at the microscopic level using molecular dynamics simulations.


2017 ◽  
Author(s):  
◽  
Sangeeta Singh

The thermodynamic properties of mixtures involving ionic liquids (ILs) with organic acid (acetic acid or propanoic acid) or acetonitrile at different temperatures were determined. The ILs used were imidazolium-based: 1-ethyl-3-methylimidazolium ethyl sulphate [EMIM]+[EtSO4]-, 1-butyl- 3-methylimidazolium thiocyanate [BMIM]+[SCN]- and 1-butyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide ([BMIM]+[Tf2N]-. The ternary excess molar volume (V E ), isentropic compressibility (ks) and deviation in isentropic compressibility ( ks123 ) were determined for four ternary liquid mixtures of {[EMIM]+[EtSO4]- or [BMIM]+[SCN]− + acetic or propionic acid + acetonitrile} at different temperatures (293.15, 298.15, 303.15, 308.15 and 313.15) K and at a pressure of 0.1 MPa with aid of the experimental density (ρ), speed of sound (u) data. The calculated data were correlated by using the Cibulka equation with the help of Redlich–Kister parameters obtained from fitting the Redlich–Kister equation for the corresponding binary systems. Furthermore, the density and speed of sound were also measured for eight corresponding binary systems at the same experimental conditions. The binary excess molar volume, isentropic compressibility and deviation in isentropic compressibility were also calculated for measured systems and fitted to the Redlich–Kister equation to obtain the Redlich–Kister parameters as well as to check the accuracy of measured data which were used to correlated experimental data using Cibulka equation. These results were discussed, in terms of how the sign and magnitude of thermodynamic functions were influenced by the addition of a third component to liquid systems. Also, the possible molecular and pair-wise interactions between component molecules and the effect of temperature on the thermophysical and thermodynamic properties were predicted. In addition, the work focussed on application of ([BMIM]+[Tf2N]-) ionic liquid for the separations of (alkane/aromatic), (alkane/alk-1-ene), (cycloalkane/aromatic) and (water/alkan-1-ol) using gas- liquid chromatography (GLC) technique. The activity coefficients at infinite dilution, , for 31 organic solutes (alkanes, cycloalkanes, alkenes, alkynes, aromatics, alkanol and ketones) and water in ionic liquid were measured at temperatures of (323.15, 333.15, 343.15, 353.15 and 363.15) K. Stationary phase loadings of (42.83 and 68.66) % by mass were used to ensure repeatability of E , measurements. Partial molar excess enthalpies at infinite dilution, H1 , were also determined. The selectivities, S , and capacities, k , were determined for the above separations. The separating ij j ability of the investigated ionic liquid was compared with previously investigated ionic liquids and industrial solvents such as sulfolane, n-methyl-2-pyrrolidine (NMP) and n-formylmorpholine (NFM). The results obtained suggested that in general, the [BMIM]+[Tf2N]− had outperformed the conventional solvents such as sulfolane, NMP and NFM in terms of selectivity, while the [BMIM][Tf2N] had in general, performed better overall when the performance index was used for comparison.


2018 ◽  
Vol 20 (15) ◽  
pp. 9938-9949 ◽  
Author(s):  
Borja Docampo-Álvarez ◽  
Víctor Gómez-González ◽  
Trinidad Méndez-Morales ◽  
Julio R. Rodríguez ◽  
Oscar Cabeza ◽  
...  

Mixtures of protic and aprotic ionic liquids exhibit non-ideal behavior with increasing alkyl chain length, caused by the formation of molecular complexes.


2015 ◽  
Vol 17 (47) ◽  
pp. 31947-31955 ◽  
Author(s):  
Sergey A. Kislenko ◽  
Victoria A. Nikitina ◽  
Renat R. Nazmutdinov

Molecular dynamics simulations were performed to address the permeability of defectless alkanethiol self-assembled monolayers (SAMs) on charged and uncharged Au(111) surfaces in 1-butyl-3-methylimidazolium ([bmim][BF4]) room-temperature ionic liquid (IL).


2018 ◽  
Vol 20 (15) ◽  
pp. 10193-10203 ◽  
Author(s):  
Sten Sarman ◽  
Yong-Lei Wang ◽  
Patrick Rohlmann ◽  
Sergei Glavatskih ◽  
Aatto Laaksonen

Comparison between the theoretical and experimental viscosity of an ionic liquid.


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