Electrostatic interactions in ionic liquids: the dangers of dipole and dielectric descriptions

2010 ◽  
Vol 12 (8) ◽  
pp. 1922 ◽  
Author(s):  
Mark N. Kobrak ◽  
Hualin Li
Keyword(s):  
Ionic Liquids ◽  
Electrostatic Interactions

scholarly journals Voltammetric sensor based on long alkyl chain tetraalkylammonium ionic liquids comprising ascorbate anion for determination of nitrite

2021 ◽  
Vol 188 (2) ◽  
Author(s):  
Tomasz Rębiś ◽  
Michał Niemczak ◽  
Patrycja Płócienniczak ◽  
Juliusz Pernak ◽  
Grzegorz Milczarek
Keyword(s):  
Ionic Liquids ◽  
Electrostatic Interactions ◽  
Film Surface ◽  
Modified Electrodes ◽  
Voltammetric Sensor ◽  
Nitrite Oxidation ◽  
Alkyl Chains ◽  
Modified Surface ◽  
Influence Of Ph

AbstractAn electrochemical sensor was fabricated utilizing ionic liquids possessing cations with long alkyl chains such as trimethyl octadecylammonium and behenyl trimethylammonium and ascorbate anion. The ionic liquids were drop-coated onto the electrode. Thin modifying layers were prepared. Cyclic voltammetric investigations revealed electrostatic interactions between the electrochemical probes and the modified surface, proving that a positive charge was established at the film surface. Hence, negatively charged species such as nitrite can be pre-concentrated on the surface of presented modified electrodes. The fabricated electrodes have been used as a voltammetric sensor for nitrite. Due to the electrostatic accumulation properties of long alkyl cation, the assay exhibits a remarkable improvement in the voltammetric response toward nitrite oxidation. The influence of pH on the electrode response was thoroughly investigated, and the mechanism of the electrode was established. The developed sensor showed a linear electrochemical response in the range 1.0–50 μM with a detection limit of 0.1 μM. The electrode revealed good storage stability, reproducibility, and anti-interference ability. The determination of nitrite performed in curing salts brought satisfactory results. Graphical abstract

scholarly journals Wetting transition of ionic liquids at metal surfaces: A computational molecular approach to electronic screening using a virtual Thomas-Fermi fluid

2020 ◽  
Author(s):  
Alexander Schlaich ◽  
Dongliang Jin ◽  
Lyderic Bocquet ◽  
Benoit Coasne
Keyword(s):  
Ionic Liquids ◽  
Energy Storage ◽  
Electrostatic Interactions ◽  
Debye Length ◽  
Wetting Transition ◽  
Molecular Fluids ◽  
Thomas Fermi ◽  
Electronic Screening ◽  
Novel Approach ◽  
The Impact

Abstract Of particular relevance to energy storage, electrochemistry and catalysis, ionic and dipolar liquids display a wealth of unexpected fundamental behaviors – in particular in confinement. Beyond now well-documented adsorption, overscreening and crowding effects1,2,3, recent experiments have highlighted novel phenomena such as unconventional screening4 and the impact of the electronic nature – metallic versus insulating – of the confining surface on wetting/phase transitions5,6. Such behaviors, which challenge existing theoretical and numerical modeling frameworks, point to the need for new powerful tools to embrace the properties of confined ionic/dipolar liquids. Here, we introduce a novel atom-scale approach which allows for a versatile description of electronic screening while capturing all molecular aspects inherent to molecular fluids in nanoconfined/interfacial environments. While state of the art molecular simulation strategies only consider perfect metal or insulator surfaces, we build on the Thomas-Fermi formalism for electronic screening to develop an effective approach that allows dealing with any imperfect metal between these asymptotes. The core of our approach is to describe electrostatic interactions within the metal through the behavior of a `virtual' Thomas-Fermi fluid of charged particles, whose Debye length sets the Thomas-Fermi screening length λ in the metal. This easy-to-implement molecular method captures the electrostatic interaction decay upon varying λ from insulator to perfect metal conditions, while describing very accurately the capacitance behavior – and hence the electrochemical properties – of the metallic confining medium. By applying this strategy to a nanoconfined ionic liquid, we demonstrate an unprecedented wetting transition upon switching the confining medium from insulating to metallic. This novel approach provides a powerful framework to predict the unsual behavior of ionic liquids, in particular inside nanoporous metallic structures, with direct applications for energy storage and electrochemistry.

scholarly journals Solvation of apolar compounds in protic ionic liquids: the non-synergistic effect of electrostatic interactions and hydrogen bonds

2017 ◽  
Vol 19 (37) ◽  
pp. 25352-25359 ◽  
Author(s):  
I. A. Sedov ◽  
T. I. Magsumov ◽  
T. M. Salikov ◽  
B. N. Solomonov
Keyword(s):  
Ionic Liquids ◽  
Hydrogen Bonds ◽  
Synergistic Effect ◽  
Electrostatic Interactions ◽  
Protic Ionic Liquids ◽  
Better Than

Protic ionic liquids can dissolve apolar compounds better than aprotic ionic liquids.

Strong Hydrogen Bonds Are Not Shielded in Ionic Liquids

2019 ◽  
Author(s):  
Teresa Naranjo ◽  
Rubén Álvarez-Asencio ◽  
Patricia Pedraz ◽  
Belén Nieto-Ortega ◽  
Enrique Burzurí ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
Melting Point ◽  
Hydrogen Bonds ◽  
Physical Properties ◽  
Organic Solvents ◽  
Electrostatic Interactions ◽  
Room Temperature ◽  
Noncovalent Interactions ◽  
Binding Constants ◽  
Information Storage

Hydrogen bonds are arguably the most important of noncovalent interactions. The physical properties of water and the information storage in DNA depend on H-bonding, for instance. To this day, the balance between the Coulombic and covalent contributions to H-bonds is still under debate. Here, we show that H-bonded host-guest systems associate in ionic liquids, pure salts with melting point below room temperature, in which dipole-dipole electrostatic interactions should be negligible in comparison with dipole-charge interactions. Binding constants (<i>K</i><sub>a</sub>) obtained from titrations of four H-bonded host-guest systems in two organic solvents and two ionic liquids yield smaller yet comparable <i>K</i><sub>a</sub>values in ionic liquids than in organic solvents. We also detect the association event using force spectroscopy. Our results indicate that strong H-bonds are only moderately affected by surroundings composed entirely of charges, suggesting that the balance of Coulombic to covalent forces is not tipped towards the former.

Strong Hydrogen Bonds Are Not Shielded in Ionic Liquids

2019 ◽  
Author(s):  
Teresa Naranjo ◽  
Rubén Álvarez-Asencio ◽  
Patricia Pedraz ◽  
Belén Nieto-Ortega ◽  
Enrique Burzurí ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
Melting Point ◽  
Hydrogen Bonds ◽  
Physical Properties ◽  
Organic Solvents ◽  
Electrostatic Interactions ◽  
Room Temperature ◽  
Noncovalent Interactions ◽  
Binding Constants ◽  
Information Storage

Hydrogen bonds are arguably the most important of noncovalent interactions. The physical properties of water and the information storage in DNA depend on H-bonding, for instance. To this day, the balance between the Coulombic and covalent contributions to H-bonds is still under debate. Here, we show that H-bonded host-guest systems associate in ionic liquids, pure salts with melting point below room temperature, in which dipole-dipole electrostatic interactions should be negligible in comparison with dipole-charge interactions. Binding constants (<i>K</i><sub>a</sub>) obtained from titrations of four H-bonded host-guest systems in two organic solvents and two ionic liquids yield smaller yet comparable <i>K</i><sub>a</sub>values in ionic liquids than in organic solvents. We also detect the association event using force spectroscopy. Our results indicate that strong H-bonds are only moderately affected by surroundings composed entirely of charges, suggesting that the balance of Coulombic to covalent forces is not tipped towards the former.

scholarly journals Alkyl Chain Length Effects of Imidazolium Ionic Liquids on Electrical and Mechanical Performances of Polyacrylamide/Alginate-Based Hydrogels

Gels ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 164
Author(s):  
Chen-Kang Chen ◽  
Po-Wen Chen ◽  
Huan-Jung Wang ◽  
Mei-Yu Yeh
Keyword(s):  
Ionic Liquids ◽  
Chain Length ◽  
Electrostatic Interactions ◽  
Alkyl Chain ◽  
Electrochemical Impedance ◽  
Alkyl Chain Length ◽  
Strain Sensors ◽  
Potential Candidate ◽  
Diverse Range ◽  
Alginate Hydrogels

Conductive hydrogels with stretchable, flexible and wearable properties have made significant contributions in the area of modern electronics. The polyacrylamide/alginate hydrogels are one of the potential emerging materials for application in a diverse range of fields because of their high stretch and toughness. However, most researchers focus on the investigation of their mechanical and swelling behaviors, and the adhesion and effects of the ionic liquids on the conductivities of polyacrylamide/alginate hydrogels are much less explored. Herein, methacrylated lysine and different alkyl chain substituted imidazole-based monomers (IMCx, x = 2, 4, 6 and 8) were introduced to prepare a series of novel pAMAL-IMCx-Ca hydrogels. We systematically investigated their macroscopic and microscopic properties through tensile tests, electrochemical impedance spectra and scanning electron microscopy, as well as Fourier transform infrared spectroscopy, and demonstrated that an alkyl chain length of the IMCx plays an important role in the designing of hydrogel strain sensors. The experiment result shows that the hexyl chains of IMC6 can effectively entangle with LysMA through hydrophobic and electrostatic interactions, which significantly enhance the mechanical strength of the hydrogels. Furthermore, the different strain rates and the durability of the pAMAL-IMC6-Ca hydrogel were investigated and the relative resistance responses remain almost the same in both conditions, making it a potential candidate for wearable strain sensors.

scholarly journals Hydrogen-bonded host–guest systems are stable in ionic liquids

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Teresa Naranjo ◽  
Rubén Álvarez-Asencio ◽  
Patricia Pedraz ◽  
Belén Nieto-Ortega ◽  
Sara Moreno-Da Silva ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
Melting Point ◽  
Supramolecular Chemistry ◽  
Organic Solvents ◽  
Electrostatic Interactions ◽  
Room Temperature ◽  
Binding Constants ◽  
Force Spectroscopy ◽  
Solvation Processes ◽  
Hydrogen Bonded

Abstract We show that H-bonded host–guest systems associate in ionic liquids (ILs), pure salts with melting point below room temperature, in which dipole–dipole electrostatic interactions should be negligible in comparison with dipole-charge interactions. Binding constants (Ka) obtained from titrations of four H-bonded host–guest systems in two organic solvents and two ionic liquids yield smaller yet comparable Ka values in ionic liquids than in organic solvents. We also detect the association event using force spectroscopy, which confirms that the binding is not solely due to (de)solvation processes. Our results indicate that classic H-bonded host–guest supramolecular chemistry takes place in ILs. This implies that strong H-bonds are only moderately affected by surroundings composed entirely of charges, which can be interpreted as an indication that the balance of Coulombic to covalent forces in strong H-bonds is not tipped towards the former.

Towards understanding the effect of electrostatic interactions on the density of ionic liquids

2009 ◽  
Vol 279 (2) ◽  
pp. 87-91 ◽  
Author(s):  
Junfeng Wang ◽  
Chunxi Li ◽  
Chong Shen ◽  
Zihao Wang
Keyword(s):  
Ionic Liquids ◽  
Electrostatic Interactions
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