Interaction Of Ionic Liquids Research Articles

Intermolecular interactions between imidazolium- and cholinium-based ionic liquids and lysozyme: Regularities and peculiarities

The intermolecular interactions of imidazolium- and cholinium-based ionic liquids and hen egg-white lysozyme (HEWL) were studied by spectral, thermodynamic, and computational methods. The cholinium- and imidazolium-based ionic liquids: choline chloride [Ch][Cl], choline dihydrogenphosphate [Ch][DHP], choline acetate [Ch][OAc], 1-butyl-3-methylimidazolium tetrafluoroborate [BMIM][BF4], 1-butyl-3-methylimidazolium trifluoromethanesulfonate [BMIM][TfO], 1-butyl-3-methylimidazolium acetate [BMIM][OAc] and 1-butyl-3-methylimidazolium methanesulfonate [BMIM][CH3SO3] were selected. The proton donor and acceptor abilities of ionic liquids were determined based on gas chromatography and solution calorimetry data. The temperature denaturation of HEWL in ionic-liquid solution was observed using capillary differential scanning calorimetry (DSC) and circular dichroism spectroscopy (CD). The interaction of ionic liquids with HEWL at the standard temperature was accessed by monitoring the protein’s fluorescence changes. The effect of the ionic liquid on the stability of the native structure of HEWL strongly depends on the proton acceptor ability of ionic liquids. The denaturation temperature of the native structure HEWL is linearly correlated with the enthalpy of the specific interaction (hydrogen bonding) of methanol and trichloromethane in the studied ionic liquids. At the same time, fluorescence data revealed ionic liquid-specific effects, which depend on both ions in the ionic liquid. Both fluorescence and molecular docking data indicate a lack of strong binding between the studied ionic liquids and HEWL.

Interaction of ionic liquids with human serum albumin in the view of bioconcentration: a preliminary study

Bioaccumulation potential is critical in PBT and risk assessment of chemicals. However, for ionic liquids (ILs), this aspect remains neglected. It is especially important to fill this gap, because for this group of compounds, existing data confirm their risk of being environmentally persistent and toxicity. Moreover, considering preliminary reports on the interactions of ILs with lipids, it may be assumed that ILs have a higher potential for bioaccumulation than indicated by previous estimations built upon octanol–water partition coefficients. Moreover, the bioconcentration of ionizable chemical compounds may also be strongly related to plasma protein contents. Therefore, in this work, the affinity of a set of imidazolium cations and organic anions, and their combination to human serum albumin (HSA) was determined. The obtained results reveal that both cations and anions can be strongly bound to HSA, and blood proteins might play an important role in overall bioaccumulation. Furthermore, it was observed that HSA binding properties towards IL cations depend on the hydrophobicity of cations. The obtained data also provide indication that cation–anion interaction may affect ILs ions affinity to HSA.

Interaction of imidazolium-based ionic liquids with supported phospholipid bilayers as model biomembranes.

The cytotoxicity of ionic liquids (ILs) has been receiving attention in the context of the biological and environmental impact of their vast field of applications. It has been ascertained that the cell membrane is the main target of ILs when they interact with microorganisms, cells and bacteria; nevertheless, studies at the micro- and nano-scale aiming at better understanding of the fundamental mechanisms of toxicity of ILs are lacking. In this work, we used atomic force microscopy (AFM) to investigate the impact of room-temperature ILs on the mechanical, morphological and electrostatic properties of solid-supported DOPC phospholipid bilayers, taken as models of biomembranes. In particular, we have characterized the concentration-dependent and time-dependent evolution of the morphological, structural and mechanical properties of DOPC lipid membranes in the presence of imidazolium-based ILs with different alkyl chain lengths and hydrophilic/hydrophobic characteristics. The majority of ILs investigated were found to possess the ability of restructuring the lipid bilayer, through the formation of new IL/lipid complexes, showing distinctive morphological features (increase of area and roughness). The nanomechanical analysis of the lipid membrane exposed to ILs revealed a progressive, concentration-dependent perturbation of the structural ordering and rigidity of the membrane, evidenced by a decrease in the breakthrough force, Young's modulus and area stretching modulus. AFM detected a modification of the electrostatic double-layer at the membrane surface, in terms of a reduction of the original negative surface charge density, suggesting a progressive stratification of cations on the exposed leaflet of the lipid membrane. Our findings may be helpful in designing novel ILs with tailored interaction with biological membranes.

Experimental investigation into the development and evaluation of ionic liquid and its graphene oxide nanocomposite as novel pour point depressants for waxy crude oil

Wax deposition in pipelines transporting crude oil is a serious problem as wax tends to precipitate under low temperature conditions observed during pipeline flow. The current research work embarks on the development of novel nanocomposite pour point depressant (PPD) for waxy crude oils. Two additives were synthesized in the laboratory: 1-octyl 3-methylimidazolium chloride [(OMIM)Cl], and a novel class of nanocomposite PPD: PPDR-GO. These additives were tested on an Indian waxy crude oil and proved to be acting as PPDs and flow improvers. Pour point reduction occurred from 39 °C to 21 °C with [(OMIM)Cl], while the depression occurred from 39 °C up to 9 °C with nanocomposite PPDR-1%GO, suggesting significant improvement in the flow ability of the crude oil. The PPDs also induced reduction in the apparent viscosities of crude oil significantly from 7 Pa s down to 0.04 Pa s by (OMIM)Cl and 0.02 Pa s (at higher shear rates and temperatures) by PPDR-1%GO respectively. Apart from the pour point and viscosity tests, the effectiveness of the additives were tested by cold finger, gelation point and aging tests and they produced encouraging set of results. The characterization of the two PPDs performed using spectroscopic analytical techniques FTIR, Proton NMR, XRD and Raman helped identifying the presence of different components and confirm their structure. The purpose of this work is to develop new pour point depressants which are highly effective for providing flow assurance of waxy crude oils. This research also aimed at improving the synthesized PPDs in important areas such as improving dispersion of VGO nanosheets in nanocomposite matrix, enhanced pour point depression ability, low dosage requirement of PPDs, eliminating the need of solvent for PPDs. The action mechanism of the PPDs develops theoretical insights on interactions of ionic liquids, graphene oxide sheets and asphaltenes with the wax structures, which would be highly beneficial for future research.

The interactions of chelate-based ionic liquids: from the perspective of vaporization enthalpy.

The vaporization enthalpies of [CnTPP][Cu(F6-acac)3] (n = 14, 16) and [Cnmim][Cu(F6-acac)3] (n = 8, 10), a new type of chelate-based ionic liquids (ChILs), were measured by thermogravimetric analysis (ΔglHom(Tav) = 73.2-83.7 kJ mol-1), which decreased compared to their non-chelate counterparts (difference up to 34.1 kJ mol-1). This can be explained by the fact that the increase in the polar region size by chelate ions mainly leads to the decrease in Coulomb forces based on the micro-biphasic separation in ionic liquids. Vaporization enthalpies at experimental temperatures were adjusted to a reference temperature by the Verevkin's method, and compared with the data calculated by the Kabo's method, which illustrated clear differences on ChILs. In addition, some physicochemical properties of [CnTPP][Cu(F6-acac)3] (n = 14, 16) were measured including density, viscosity, conductivity, and surface tension.

X-ray photoelectron spectroscopy of morpholinium ionic liquids: impact of a long alkyl side substituent on the cation-anion interactions.

In this study, X-ray photoelectron spectroscopy is used to analyse nine morpholinium ionic liquids, which are of great interest in green chemistry because of their low toxicity and high recyclability. The effect of the alkyl chain length on the aliphatic C 1s binding energy and the impact of the anion basicity on the cationic N 1s and O 1s binding energies are investigated. It is concluded that by changing the basicity of the anion, there is a more notable change in the electronic environment of the oxygen centre. The impact of a long alkyl side substituent on the cation-anion interactions is also discussed. It is observed that there is an intense charge shielding effect of the alkyl side chain in the cases of octyl and dodecyl substituents, which is reflected in the reduced Br 3d5/2 binding energy.

Atomic force microscopy probing interactions and microstructures of ionic liquids at solid surfaces.

Ionic liquids (ILs) are room temperature molten salts that possess preeminent physicochemical properties and have shown great potential in many applications. However, the use of ILs in surface-dependent processes, e.g. energy storage, is hindered by the lack of a systematic understanding of the IL interfacial microstructure. ILs on the solid surface display rich ordering, arising from coulombic, van der Waals, solvophobic interactions, etc., all giving near-surface ILs distinct microstructures. Therefore, it is highly important to clarify the interactions of ILs with solid surfaces at the nanoscale to understand the microstructure and mechanism, providing quantitative structure-property relationships. Atomic force microscopy (AFM) opens a surface-sensitive way to probe the interaction force of ILs with solid surfaces in the layers from sub-nanometers to micrometers. Herein, this review showcases the recent progress of AFM in probing interactions and microstructures of ILs at solid interfaces, and the influence of IL characteristics, surface properties and external stimuli is thereafter discussed. Finally, a summary and perspectives are established, in which, the necessities of the quantification of IL-solid interactions at the molecular level, the development of in situ techniques closely coupled with AFM for probing IL-solid interfaces, and the combination of experiments and simulations are argued.

Molecular interactions of ionic liquids with SiO2 surfaces determined from colloid probe atomic force microscopy.

Ionic liquids (ILs) interact strongly with many different types of solid surfaces in a wide range of applications, e.g. lubrication, energy storage and conversion, etc. However, due to the nearly immeasurable large number of potential ILs available, identifying the appropriate ILs for specific solid interfaces with desirable properties is a challenge. Theoretical studies are highly useful for effective development of design and applications of these complex molecular systems. However, obtaining reliable force field models and interaction parameters is highly demanding. In this work, we apply a new methodology by deriving the interaction parameters directly from the experimental data, determined by colloid probe atomic force microscopy (CP-AFM). The reliability of the derived interaction parameters is tested by performing molecular dynamics simulations to calculate translational self-diffusion coefficients and comparing them with those obtained from NMR diffusometry.

Surface Interaction of Ionic Liquids: Stabilization of Polyethylene Terephthalate-Degrading Enzymes in Solution.

The effect of aqueous solutions of selected ionic liquids solutions on Ideonella sakaiensis PETase with bis(2-hydroxyethyl) terephthalate (BHET) substrate were studied by means of molecular dynamics simulations in order to identify the possible effect of ionic liquids on the structure and dynamics of enzymatic Polyethylene terephthalate (PET) hydrolysis. The use of specific ionic liquids can potentially enhance the enzymatic hydrolyses of PET where these ionic liquids are known to partially dissolve PET. The aqueous solution of cholinium phosphate were found to have the smallest effect of the structure of PETase, and its interaction with (BHET) as substrate was comparable to that with the pure water. Thus, the cholinium phosphate was identified as possible candidate as ionic liquid co-solvent to study the enzymatic hydrolyses of PET.

Density functional theory on ionic liquid as carbonate scale dissolver in petroleum pipelines

The carbonate scale is the common oilfield scale found in the petroleum pipeline, which will cause flow assurance problems. In the purpose to conquer this problem, the alternative approach is to use ionic liquids (ILs) particularly in dissolving carbonate scale. The main objective of this study is to determine the effective ILs to dissolve carbonate scale in petroleum pipelines, and to evaluate the effect of intermolecular interaction in ILs toward their properties such as dissolution capabilities. The density functional theory (DFT) calculation is used to investigate the intermolecular interaction of a series of different ion pair, namely cations and anions-based of ILs with carbonate ion. All the calculations are completed by Gaussian software at the hybrid Becke 3-Lee-Yang-Parr (B3LYP) level using the 6-311++G(d, p) basis set. The optimized structure of carbonate ion and ion pairs of ILs have been obtained from the calculation which was further complemented by harmonic vibrational frequency, binding energies, bond type, bond order, and natural bond orbital (NBO). The binding energy for the cation and anion-based ILs are obtained where the ammonium ion is −302.2627 kJ/mol and tetrafluoroborate ion is −562.9194 kJ/mol which depict to have the highest value compare to others. Both of them are made up of the single bond and are characterized as the polar covalent bond. The NBO analysis pointed out the higher second-order perturbation energy, E (2) for ammonium ion is at a lone pair, LP (1) N 9 to antibonding sigma, BD*(1) O 3H 6 while BF4 ion is at lone pair LP (3) F 2 to antibonding lone pair, LP*(1) Ca 6. The selective ILs, ammonium tetrafluoroborate shown the higher negative binding energy which is −371.93 kJ/mol having the same nature of bond type and bond order from the findings in cation and anion-based ILs.

The interaction of the surface active ionic liquid with nonionic surfactants (Triton X-100 and Triton X-405) in aqueous solution by using tensiometry method

The synergistic interactions of the surface active ionic liquid (1-dodecyl-3-methylimidazolium bromide, IL) with non-ionic surfactants TritonX-100 (TX-100) and TritonX-405 (TX-405) were investigated in aqueous solution at various mole fractions by using the surface tension technique at 298.15 K. In this work, the pendant drop method was used for surface tension measurement of solutions. The surfactant properties such as critical micelle concentration (CMC), micellar mole fractions (X1Rub), interaction parameter (βm), and activity coefficients of components in the mixed micelle (f1Rub and f2Rub) were calculated by theoretical Clint and Rubingh models. Also, surface and adsorption parameters, maximum surface excess values (Γmax), minimum area per molecule (Amin), surface tension at CMC (σCMC), and surface pressure at the CMC (πCMC) values have been estimated in (TX-405/TX-100 + IL + water) systems. The synergistic effects operating in these amphiphile mixtures were confirmed by the negative values of the interaction parameter. Generally, the CMC value of surfactant solution increases with the addition of ionic liquid in the mixture. It was demonstrated that IL can be judiciously used at different mole fractions for modifying the physicochemical properties of (TX-100 and TX-405). Different thermodynamics parameters were computed for mixtures and were also discussed in detail. The Gibbs free energy change of micellization (ΔGmo), the standard Gibbs energy of adsorption (ΔGado) and the excess free energy of micellization (ΔGexRub) values have been estimated at different compositions. The calculation of thermodynamic parameters shows that the micellization process is spontaneous and becomes more favorable with addition of the non-ionic component in mixture.

Low-temperature Hg0 abatement by ionic liquid based on weak interaction

Low-temperature gaseous elemental mercury (Hg0) abatement is an objective demand in industrial flue gas treatment. In this work, we proposed a new approach for Hg0 capture via weak interaction of ionic liquids. Ionic liquids with varied anions (1-butyl-3-methylimidazolium thioacetate ([Bmim][ThAc]), 1-butyl-3-methylimidazolium diethyldithiocarbamate ([Bmim][DTCR]), and 1-butyl-3-methylimidazolium ethylxanthate ([Bmim][EX])) were designed and synthesized. The interaction energies between ionic liquids and elemental mercury were proved to be positively related to mercury removal efficiency, revealing that the electrostatic interaction derived physical adsorption from anions is the dominant factor affecting mercury removal performance. [Bmim][ThAc] with the largest anionic electrostatic interaction energy showed the best mercury abatement performance, achieving a Hg0 removal efficiency of over 98% and an adsorption capacity of 10.66 mg/g at 50 °C. The influence of temperature and the results of mercury temperature-programmed desorption (Hg-TPD), X-ray photoelectron spectroscopy (XPS) further confirmed that the ionic liquid combines with elemental mercury through physical adsorption. The work provides a new perspective on designing high-efficiency sorbents for mercury removal at low temperature.

Exploring the Interactions of Ionic Liquids with Bio-Organic Amphiphiles Using Computational Approaches

Bio-organic amphiphiles have been shown to effectively impart unique physicochemical properties to ionic liquids resulting in the formation of versatile hybrid composites. In this work, we utilized computational methods to probe the formation and properties of hybrids prepared by mixing three newly designed bio-organic amphiphiles with 14 ionic liquids containing cholinium or glycine betaine cations and a variety of anions. The three amphiphiles were designed such that they contain unique biological moieties found in nature by conjugating (a) malic acid with the amino acid glutamine, (b) thiomalic acid with the antiviral, antibacterial pyrazole compound [3-(3,5-dimethyl-1H-pyrazol-1-yl)benzyl]amine, and (c) Fmoc-protected valine with diphenyl amine. Conductor-like screening model for real solvents (COSMO-RS) was used to obtain sigma profiles of the hybrid mixtures and to predict viscosities and mixing enthalpies of each composite. These results were used to determine optimal ionic liquid-bio-organic amphiphile mixtures. Molecular dynamics simulations of three optimal hybrids were then performed, and the interactions involved in the formation of the hybrids were analyzed. Our results indicated that cholinium-based ILs interacted most favorably with the amphiphiles through a variety of inter- and intramolecular interactions. This work serves to illustrate important factors that influence the interactions between bio-organic amphiphiles and bio-ILs and aids in the development of novel ionic liquid-based composites for a wide variety of potential biological applications.

Exploring the interaction of ionic liquids with Al12N12 and Al12P12 nanocages for better electrode-electrolyte materials in super capacitors

For designing better energy storage devices, the interfacial interaction between ILs and nanostructure is a prerequisite. In the present study, the interaction of ionic liquids such as [EMIm]+[X]− on Al12N12 and Al12P12 nanocages has been investigated using DFT theory. The complexes of Al12P12 nanocage exhibit higher values of adsorption energies than those of Al12N12. The adsorption energies of IL-complexes range from −38.9 to −63.6 kcal/mol. Non-covalent interaction (NCI) and quantum theory of atoms in molecules (QTAIM) analyses revealed non-covalent interactions between the ionic liquids and nanocages. NBO analysis shows charge transfer between the ionic liquids and Al12N12 and Al12P12 nanocages, which results in significant enhancement of dipole moment values of IL-complexes. [EMI]+ [X]−@Al12P12 complexes show higher dipole moment values than those of [EMI]+ [X]−@Al12N12 complexes. FMO analysis depicts a decrease in the HOMO-LUMO energy gap of IL-complexes, enhancing the electrical conductivity of these complexes. Furthermore, the calculated quantum molecular descriptors show that ILs adsorbed Al12N12 complexes are less reactive than ILs adsorbed Al12P12 nanocages. Thermodynamic properties revealed that the adsorption of ILs on Al12N12 and Al12P12 is an exothermic and spontaneous process. This study illustrates that the electronic properties of Al12N12 and Al12P12 nanocages are fine-tuned by the adsorption of ionic liquids. This study provides an efficient approach to design better electrode–electrolyte materials for super capacitors, fuel cells, ion batteries, and solar cells.

A DLPNO-CCSD(T) benchmarking study of intermolecular interactions of ionic liquids.

The accuracy of correlation energy recovered by coupled cluster single-, double-, and perturbative triple-excitations, CCSD(T), has led to the method being considered the gold standard of computational chemistry. The application of CCSD(T) has been limited to medium-sized molecular systems due to its steep scaling with molecular size. The recent development of alternative domain-based local pair natural orbital coupled-cluster method, DLPNO-CCSD(T), has significantly broadened the range of chemical systems to which CCSD(T) level calculations can be applied. Condensed systems such as ionic liquids (ILs) have a large contribution from London dispersion forces of up to 150 kJ mol-1 in large-scale clusters. Ionic liquids show appreciable charge transfer effects that result in the increased valence orbital delocalization over the entire ionic network, raising the question whether the application of methods based on localized orbitals is reliable for these semi-Coulombic materials. Here the performance of DLPNO-CCSD(T) is validated for the prediction of correlation interaction energies of two data sets incorporating single-ion pairs of protic and aprotic ILs. DLPNO-CCSD(T) produced results within chemical accuracy with tight parameter settings and a non-iterative treatment of triple excitations. To achieve spectroscopic accuracy of 1 kJ mol-1 , especially for hydrogen-bonded ILs and those containing halides, the DLPNO settings had to be increased by two orders of magnitude and include the iterative treatment of triple excitations, resulting in a 2.5-fold increase in computational cost. Two new sets of parameters are put forward to produce the performance of DLPNO-CCSD(T) within chemical and spectroscopic accuracy.

Effects of Ionic Liquids on Laccase from Trametes versicolor

Interactions between ionic liquids and biomolecules are of great interest due to the intrinsic properties of ionic liquids and the flexibility allowed by mixing and matching cations and anions to create unique ionic liquids. A number of ionic liquid–biomolecule studies have focused on interactions with proteins, including industrially relevant enzymes. One of these, laccase from Trametes versicolor, is a naturally derived enzyme used in the breakdown of phenolic compounds in a wide variety of industries, especially useful in breakdown of lignocellulosic materials. Here, a combination of experiments and molecular dynamics (MD) simulations was used to investigate the interactions of ionic liquids with laccase. Enzyme kinetics assays indicated that ionic liquids composed of tetramethylguanidine (TMG) and either serine or threonine caused significant reduction in enzymatic activity, while kinetics was not impacted by TMG-Asp or TMG-Glu ionic liquids. Similarly, intrinsic fluorescence of laccase in the presence of TMG-Ser and TMG-Thr exhibited a shift in spectral properties consistent with structural destabilization, but again TMG-Asp and TMG-Glu had no impact. MD simulations of laccase and ABTS with/without TMG-Ser ionic liquid provided insight into the deactivation mechanism of laccase. The simulations indicated that TMG-Ser disrupts laccase’s electron transfer mechanism.

Physico-chemistry and adhesion kinetics of algal biofilm on polyethersulfone (PES) membrane with different surface wettability

Microalgal biofilm growth on porous substrates has recently garnered extensive attention with the advantage of high biomass productivity with low liquid culture volume. In such cultivation, the surface characteristics of supporting materials play essential role supporting biofilm growth. In view of this, a study on the membrane surface wettability of a commercial polyethersulfone (PES) membrane with two different hydrophilicities was selected in a long-term benthic biofilm cultivation experiment. Findings revealed that both soluble and bounded extracellular polymeric substances (EPS) contributed towards the formation of an adhesive gel layer onto the membrane’s surfaces. The maximum accumulated cell density was achieved by C. fusiformis around 47.64 ± 4.03 × 109 cells m−2 onto phobic PES (79.29°) and the least by N. incerta around 6.40 ± 0.49 × 109 cells m−2 onto philic PES (47.56°). The fact remained that the cell attachment rate was almost similar for both A. coffeaeformis and N. incerta but with gradual reduction after day 12 for phobic PES and day 8 for philic PES for the three benthic species. The change of adhesion ratio was well explained with their respective EPS variation. The XDLVO model employed suggested the dominance of acid-base interactions in high ionic strength liquid, leading to higher global minimum energy occurring on phobic PES. Overall, the findings indicated that biofilm formation is favored on polymer substrate having lower surface energy due to the attractive interaction of the submerged surface with those biomolecules and colloids.

Ionic liquid facilitated melting of the metal-organic framework ZIF-8

Hybrid glasses from melt-quenched metal-organic frameworks (MOFs) have been emerging as a new class of materials, which combine the functional properties of crystalline MOFs with the processability of glasses. However, only a handful of the crystalline MOFs are meltable. Porosity and metal-linker interaction strength have both been identified as crucial parameters in the trade-off between thermal decomposition of the organic linker and, more desirably, melting. For example, the inability of the prototypical zeolitic imidazolate framework (ZIF) ZIF-8 to melt, is ascribed to the instability of the organic linker upon dissociation from the metal center. Here, we demonstrate that the incorporation of an ionic liquid (IL) into the porous interior of ZIF-8 provides a means to reduce its melting temperature to below its thermal decomposition temperature. Our structural studies show that the prevention of decomposition, and successful melting, is due to the IL interactions stabilizing the rapidly dissociating ZIF-8 linkers upon heating. This understanding may act as a general guide for extending the range of meltable MOF materials and, hence, the chemical and structural variety of MOF-derived glasses.

Unravelling the Interactions of Magnetic Ionic Liquids by Energy Decomposition Schemes: Towards a Transferable Polarizable Force Field.

This work aims at unravelling the interactions in magnetic ionic liquids (MILs) by applying Symmetry-Adapted Perturbation Theory (SAPT) calculations, as well as based on those to set-up a polarisable force field model for these liquids. The targeted MILs comprise two different cations, namely: 1-butyl-3-methylimidazolium ([Bmim]+) and 1-ethyl-3-methylimidazolium ([Emim]+), along with several metal halides anions such as [FeCl4]−, [FeBr4]−, [ZnCl3]− and [SnCl4]2− To begin with, DFT geometry optimisations of such MILs were performed, which in turn revealed that the metallic anions prefer to stay close to the region of the carbon atom between the nitrogen atoms in the imidazolium fragment. Then, a SAPT study was carried out to find the optimal separation of the monomers and the different contributions for their interaction energy. It was found that the main contribution to the interaction energy is the electrostatic interaction component, followed by the dispersion one in most of the cases. The SAPT results were compared with those obtained by employing the local energy decomposition scheme based on the DLPNO-CCSD(T) method, the latter showing slightly lower values for the interaction energy as well as an increase of the distance between the minima centres of mass. Finally, the calculated SAPT interaction energies were found to correlate well with the melting points experimentally measured for these MILs.

Ion transport in polymerized lyotropic liquid crystals containing ionic liquid

AbstractIn this work, we investigate the effect of morphology and segmental dynamics on ion transport in polymerized lyotropic liquid crystals (polyLLCs) containing 1‐butyl‐3‐methylimidazolium tetrafluoroborate as ionic liquid (IL). We demonstrate that two important factors, which affect ion conduction in polyLLCs, are grain size and chain density at the interface. The polyLLC with large grain size (70 nm) shows significant reduction in ion conductivity (one order of magnitude) compared to its homopolymer/IL mixture. However, the polyLLC with small grain size (20 nm) has little difference in ion conductivity compared to its homopolymer/IL mixture. It is observed that decreasing the chain density enhances the interaction of IL with polymer chains and consequently slows the relaxation of polymer chains. In addition, comparing the dynamics of polymer chains in mixtures of homopolymer/IL and templated LLC mesophases shows that the confinement in LLC structure prolongs the relaxation of polymer chains.