1
|
Lass M, Kenter T, Plessl C, Brehm M. Characterizing Microheterogeneity in Liquid Mixtures via Local Density Fluctuations. ENTROPY (BASEL, SWITZERLAND) 2024; 26:322. [PMID: 38667876 PMCID: PMC11049288 DOI: 10.3390/e26040322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Revised: 04/04/2024] [Accepted: 04/05/2024] [Indexed: 04/28/2024]
Abstract
We present a novel approach to characterize and quantify microheterogeneity and microphase separation in computer simulations of complex liquid mixtures. Our post-processing method is based on local density fluctuations of the different constituents in sampling spheres of varying size. It can be easily applied to both molecular dynamics (MD) and Monte Carlo (MC) simulations, including periodic boundary conditions. Multidimensional correlation of the density distributions yields a clear picture of the domain formation due to the subtle balance of different interactions. We apply our approach to the example of force field molecular dynamics simulations of imidazolium-based ionic liquids with different side chain lengths at different temperatures, namely 1-ethyl-3-methylimidazolium chloride, 1-hexyl-3-methylimidazolium chloride, and 1-decyl-3-methylimidazolium chloride, which are known to form distinct liquid domains. We put the results into the context of existing microheterogeneity analyses and demonstrate the advantages and sensitivity of our novel method. Furthermore, we show how to estimate the configuration entropy from our analysis, and we investigate voids in the system. The analysis has been implemented into our program package TRAVIS and is thus available as free software.
Collapse
Affiliation(s)
- Michael Lass
- Faculty of Computer Science, Electrical Engineering and Mathematics, Department of Computer Science, Paderborn University, Warburger Straße 100, 33098 Paderborn, Germany; (M.L.); (T.K.); (C.P.)
| | - Tobias Kenter
- Faculty of Computer Science, Electrical Engineering and Mathematics, Department of Computer Science, Paderborn University, Warburger Straße 100, 33098 Paderborn, Germany; (M.L.); (T.K.); (C.P.)
| | - Christian Plessl
- Faculty of Computer Science, Electrical Engineering and Mathematics, Department of Computer Science, Paderborn University, Warburger Straße 100, 33098 Paderborn, Germany; (M.L.); (T.K.); (C.P.)
| | - Martin Brehm
- Faculty of Science, Department of Chemistry, Paderborn University, Warburger Straße 100, 33098 Paderborn, Germany
| |
Collapse
|
2
|
Shamshina JL, Berton P. Ionic Liquids as Designed, Multi-Functional Plasticizers for Biodegradable Polymeric Materials: A Mini-Review. Int J Mol Sci 2024; 25:1720. [PMID: 38338998 PMCID: PMC10855424 DOI: 10.3390/ijms25031720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Revised: 01/21/2024] [Accepted: 01/26/2024] [Indexed: 02/12/2024] Open
Abstract
Measures to endorse the adoption of eco-friendly biodegradable plastics as a response to the scale of plastic pollution has created a demand for innovative products from materials from Nature. Ionic liquids (ILs) have the ability to disrupt the hydrogen bonding network of biopolymers, increase the mobility of biopolymer chains, reduce friction, and produce materials with various morphologies and mechanical properties. Due to these qualities, ILs are considered ideal for plasticizing biopolymers, enabling them to meet a wide range of specifications for biopolymeric materials. This mini-review discusses the effect of different IL-plasticizers on the processing, tensile strength, and elasticity of materials made from various biopolymers (e.g., starch, chitosan, alginate, cellulose), and specifically covers IL-plasticized packaging materials and materials for biomedical and electrochemical applications. Furthermore, challenges (cost, scale, and eco-friendliness) and future research directions in IL-based plasticizers for biopolymers are discussed.
Collapse
Affiliation(s)
- Julia L. Shamshina
- Fiber and Biopolymer Research Institute, Department of Plant and Soil Science, Texas Tech University, Lubbock, TX 79409, USA
| | - Paula Berton
- Chemical and Petroleum Engineering Department, Schulich School of Engineering, University of Calgary, Calgary, AB T2N 1N4, Canada
| |
Collapse
|
3
|
Akhlaghi Bagherjeri M, Monhemi H, Haque ANMA, Naebe M. Molecular mechanism of cellulose dissolution in N-methyl morpholine-N-oxide: A molecular dynamics simulation study. Carbohydr Polym 2024; 323:121433. [PMID: 37940258 DOI: 10.1016/j.carbpol.2023.121433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 09/19/2023] [Accepted: 09/24/2023] [Indexed: 11/10/2023]
Abstract
N-methyl morpholine-N-oxide (NMMO) is the only commercialised solvent to dissolve cellulose and produce lyocell. However, the molecular mechanism of NMMO-induced cellulose solubilisation is unknown which limits further process development. In this work, and for the first time the complete dissolution process of a large cellulose bunch was simulated in NMMO monohydrate using long microsecond molecular dynamic simulations. The dissolution process was also simulated in 1-ethyl-3-methylimidazolium acetate (EmimAc) as an efficient ionic liquid in cellulose dissolution and the results were compared with the aqueous conditions. While the cellulose bunch showed a stable and insoluble structure in pure water, it was completely and efficiently dissolved in both NMMO monohydrate and EmimAc. It was shown that the dissolution time of cellulose in NMMO monohydrate is almost twice that in EmimAc, which is in agreement with the experimental observations. Although it is revealed that hydrogen bonding is the main driving force of cellulose dissolution in NMMO monohydrate, one cannot explain the complete molecular mechanism of NMMO-induced cellulose dissolution only by considering hydrogen bonds. A straightforward molecular mechanism was proposed, in which the interactions of NMMO molecules, not with cellulose, but with the other NMMO molecules play a critical role in the dissolution process.
Collapse
Affiliation(s)
| | - Hassan Monhemi
- Department of Chemistry, University of Neyshabur, Neyshabur, Iran
| | | | - Maryam Naebe
- Deakin University, Institute for Frontier Materials, Geelong, Victoria 3216, Australia.
| |
Collapse
|
4
|
Roos E, Sebastiani D, Brehm M. A force field for bio-polymers in ionic liquids (BILFF) - part 2: cellulose in [EMIm][OAc]/water mixtures. Phys Chem Chem Phys 2023; 25:8755-8766. [PMID: 36897117 DOI: 10.1039/d2cp05636d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
We present the extension of our force field BILFF (Bio-Polymers in Ionic Liquids Force Field) to the bio-polymer cellulose. We already published BILFF parameters for mixtures of ionic liquid 1-ethyl-3-methylimidazolium acetate ([EMIm][OAc]) with water. Our all-atom force field focuses on a quantitative reproduction of the hydrogen bonds in the complex mixture of cellulose, [EMIm]+, [OAc]- and water when compared to reference ab initio molecular dynamics (AIMD) simulations. To enhance the sampling, 50 individual AIMD simulations starting from different initial configurations were performed for cellulose in solvent instead of one long simulation, and the resulting averages were used for force field optimization. All cellulose force field parameters were iteratively adjusted starting from the literature force field of W. Damm et al. We were able to obtain a very good agreement with respect to both the microstructure of the reference AIMD simulations and experimental results such as the system density (even at higher temperatures) and the crystal structure. Our new force field allows performing very long simulations of large systems containing cellulose solvated in (aqueous) [EMIm][OAc] with almost ab initio accuracy.
Collapse
Affiliation(s)
- Eliane Roos
- Institut für Chemie - Theoretische Chemie, Martin-Luther-Universität Halle-Wittenberg, Von-Danckelmann-Platz 4, 06120 Halle (Saale), Germany.
| | - Daniel Sebastiani
- Institut für Chemie - Theoretische Chemie, Martin-Luther-Universität Halle-Wittenberg, Von-Danckelmann-Platz 4, 06120 Halle (Saale), Germany.
| | - Martin Brehm
- Institut für Chemie - Theoretische Chemie, Martin-Luther-Universität Halle-Wittenberg, Von-Danckelmann-Platz 4, 06120 Halle (Saale), Germany.
| |
Collapse
|
5
|
McGrogan A, Byrne EL, Guiney R, Headen TF, Youngs TGA, Chrobok A, Holbrey JD, Swadźba-Kwaśny M. The structure of protic ionic liquids based on sulfuric acid, doped with excess of sulfuric acid or with water. Phys Chem Chem Phys 2023; 25:9785-9795. [PMID: 36647728 DOI: 10.1039/d2cp04292d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Neutron scattering with isotopic substitution was used to study the structure of concentrated sulfuric acid, and two protic ionic liquids (PILs): a Brønsted-acidic PIL, synthesised using pyridine and excess of sulfuric acid, [Hpy][HSO4]·H2SO4, and a hydrated PIL, in which an equimolar mixture of sulfuric acid and pyridine has been doped with water, [Hpy][HSO4]·2H2O. Brønsted acidic PILs are excellent solvents/catalysts for esterifications, driving reaction to completion by phase-separating water and ester products. Water-doped PILs are efficient solvents/antisolvents in biomass fractionation. This study was carried out to provide an insight into the relationship between the performance of PILs in the two respective processes and their liquid structure. It was found that a persistent sulfate/sulfuric acid/water network structure was retained through the transition from sulfuric acid to PILs, even in the presence of 2 moles (∼17 wt%) of water. Hydrogen sulfate PILs have the propensity to incorporate water into hydrogen-bonded anionic chains, with strong and directional hydrogen bonds, which essentially form a new water-in-salt solvent system, with its own distinct structure and physico-chemical properties. It is the properties of this hydrated PIL that can be credited both for the good performance in esterification and beneficial solvent/antisolvent behaviour in biomass fractionation.
Collapse
Affiliation(s)
- Anne McGrogan
- The QUILL Research Centre, School of Chemistry and Chemical Engineering, Queen's University Belfast, Belfast, BT9 5AG, UK.
| | - Emily L Byrne
- The QUILL Research Centre, School of Chemistry and Chemical Engineering, Queen's University Belfast, Belfast, BT9 5AG, UK.
| | - Robert Guiney
- The QUILL Research Centre, School of Chemistry and Chemical Engineering, Queen's University Belfast, Belfast, BT9 5AG, UK.
| | - Thomas F Headen
- Rutherford Appleton Laboratory, Chilton, Didcot, OX11 0QX, UK
| | | | - Anna Chrobok
- Department of Chemical Organic Technology and Petrochemistry, Silesian University of Technology, Krzywoustego 4, 44-100, Gilwice, Poland
| | - John D Holbrey
- The QUILL Research Centre, School of Chemistry and Chemical Engineering, Queen's University Belfast, Belfast, BT9 5AG, UK.
| | - Małgorzata Swadźba-Kwaśny
- The QUILL Research Centre, School of Chemistry and Chemical Engineering, Queen's University Belfast, Belfast, BT9 5AG, UK.
| |
Collapse
|
6
|
Triolo A, Celso FL, Perez J, Russina O. Solubility and solvation features of native cyclodextrins in 1-ethyl-3-methylimidazolium acetate. Carbohydr Polym 2022; 291:119622. [DOI: 10.1016/j.carbpol.2022.119622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 04/29/2022] [Accepted: 05/11/2022] [Indexed: 11/02/2022]
|
7
|
Ishisone K, Ori G, Boero M. Structural, dynamical, and electronic properties of the ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide. Phys Chem Chem Phys 2022; 24:9597-9607. [PMID: 35403652 DOI: 10.1039/d2cp00741j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We provide a microscopic insight, both structural and electronic, into the multifold interactions occurring in the ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [EMIM][TFSI] currently targeted for applications in next-generation low-power electronics and optoelectronic devices. To date, practical applications have remained hampered by the lack of fundamental understanding of the interactions occurring both inside the IL and at the interface with the substrate. Our first principles dynamical simulations provide accurate insights into the nature of bonding and non-bonding interactions, dynamical conformational changes and induced dipole moments, along with their statistical distributions, of this ionic liquid, that have so far not been completely unraveled. The mobilities of the two ionic species are obtained by long-lasting dynamical simulations at finite temperature, allowing simultaneous monitoring and quantification of the isomerization occurring in the IL. Moreover, a thorough analysis of the electronic structure and partial charge distributions characterizing the two components, the cation and anion, allow rationalization of the nature of the electrostatic interactions, hydrogen bonding properties of the two ionic counterparts, and the infra-red and dielectric response of the system, especially in the low frequency range, for the full characterization of the IL.
Collapse
Affiliation(s)
- Kana Ishisone
- University of Strasbourg, Institut de Physique et Chimie des Matériaux de Strasbourg, CNRS, UMR 7504, 23 rue du Loess, F-67034, France.
| | - Guido Ori
- University of Strasbourg, Institut de Physique et Chimie des Matériaux de Strasbourg, CNRS, UMR 7504, 23 rue du Loess, F-67034, France.
| | - Mauro Boero
- University of Strasbourg, Institut de Physique et Chimie des Matériaux de Strasbourg, CNRS, UMR 7504, 23 rue du Loess, F-67034, France.
| |
Collapse
|
8
|
Haque M, Abdurrokhman I, Idström A, Li Q, Rajaras A, Martinelli A, Evenäs L, Lundgren P, Enoksson P. Exploiting low-grade waste heat to produce electricity through supercapacitor containing carbon electrodes and ionic liquid electrolytes. Electrochim Acta 2022. [DOI: 10.1016/j.electacta.2021.139640] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
9
|
Mudring AV, Hammond O. Ionic Liquids and Deep Eutectics as a Transformative Platform for the Synthesis of Nanomaterials. Chem Commun (Camb) 2022; 58:3865-3892. [DOI: 10.1039/d1cc06543b] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Ionic liquids (ILs) are becoming a revolutionary synthesis medium for inorganic nanomaterials, permitting more efficient, safer and environmentally benign preparation of high quality products. A smart combination of ILs and...
Collapse
|
10
|
Li J, Farooq MQ, Petrich JW, Anderson JL, Smith EA. Fast and non-destructive determination of water content in ionic liquids at varying temperatures by Raman spectroscopy and multivariate regression analysis. Anal Chim Acta 2021; 1188:339164. [PMID: 34794575 DOI: 10.1016/j.aca.2021.339164] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 10/06/2021] [Accepted: 10/08/2021] [Indexed: 11/26/2022]
Abstract
Imidazolium acetate ionic liquids (ILs) have been utilized as promising solvents in many applications that involve varying water content and temperature. These experimental variables affect the anion-cation intermolecular interactions, which in turn influence the performance of the ILs in these applications. This paper shows Raman spectroscopy can be used as an operando method to measure water content in IL solvents when simultaneous temperature changes may occur. The Raman spectra of 1-alkyl-3-methylimidazolium acetate ILs (alkyl chain length n = 2, 4, 6, 8) with varying water content (from 0.028 to 0.899 water mole fraction) and temperature (from 78.1 K to 423.1 K) were measured. Increasing the water content or decreasing the temperature of the tested ILs weakens the anion-cation intermolecular interactions. The water content of these ILs can be quantified even in conditions when the temperature is changing using Raman spectroscopy combined with multivariate regression analysis, including principal component regression (PCR), partial-least-squares regression (PLSR), and artificial neural networks (ANNs). The ANN model combined with partial-least-squares (PLS) achieved the highest prediction accuracy of water content in ILs at varying temperatures (RMSECV = 0.017, R2CV = 99.1%, RMSEP = 0.019, R2P = 98.8%, RPD = 8.93). Raman spectroscopy provides a potential fast non-destructive operando method to monitor the water content of ILs even in applications when the temperature may be simultaneously altered; this information can lead to the optimized use of these ILs in many applications.
Collapse
Affiliation(s)
- Jingzhe Li
- The Ames Laboratory, U.S. Department of Energy, Ames, IA, 50011-3111, United States; Department of Chemistry, Iowa State University, Ames, IA, 50011-3111, United States
| | - Muhammad Qamar Farooq
- The Ames Laboratory, U.S. Department of Energy, Ames, IA, 50011-3111, United States; Department of Chemistry, Iowa State University, Ames, IA, 50011-3111, United States
| | - Jacob W Petrich
- The Ames Laboratory, U.S. Department of Energy, Ames, IA, 50011-3111, United States; Department of Chemistry, Iowa State University, Ames, IA, 50011-3111, United States
| | - Jared L Anderson
- The Ames Laboratory, U.S. Department of Energy, Ames, IA, 50011-3111, United States; Department of Chemistry, Iowa State University, Ames, IA, 50011-3111, United States
| | - Emily A Smith
- The Ames Laboratory, U.S. Department of Energy, Ames, IA, 50011-3111, United States; Department of Chemistry, Iowa State University, Ames, IA, 50011-3111, United States.
| |
Collapse
|
11
|
Qiao Q, Shi J, Shao Q. The multiscale solvation effect on the reactivity of β-O-4 of lignin dimers in deep eutectic solvents. Phys Chem Chem Phys 2021; 23:25699-25705. [PMID: 34755736 DOI: 10.1039/d1cp04342k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Deep eutectic solvents (DESs) emerge as a medium to enhance the depolymerization of lignin. One critical question is how the solvation of lignin in DESs may affect the reactivity of lignin. To shed light on this question, we investigate the solvation of four lignin dimers in three DES solutions using molecular dynamics simulations and quantum mechanical calculations. The four lignin dimers are composed of guaiacyl and syringyl units and are used as the models for lignin. The three DES solutions are composed of choline, Cl- and three acids: lactic acid, levulinic acid and oxalic acid. We investigate the preferential accumulation of individual DES components in the solvation shells and the exposure area and electrostatic potential of the β-O-4 linkage of the four lignin dimers in the three DESs. The results show that DESs could influence the affinity and nucleophilicity of the β-O-4 linkage through three effects: (1) forming a charged solvation shell, (2) varying the exposure of the β-O-4 linkage and (3) adjusting the electrostatic potential of the β-O-4 linkage. Our simulations indicate a comprehensive and multiscale effect of DESs on lignin decomposition.
Collapse
Affiliation(s)
- Qi Qiao
- Department of Chemical and Materials Engineering, University of Kentucky, Lexington, Kentucky 40506, USA.
| | - Jian Shi
- Department of Biosystems and Agricultural Engineering, University of Kentucky, Lexington, Kentucky 40506, USA
| | - Qing Shao
- Department of Chemical and Materials Engineering, University of Kentucky, Lexington, Kentucky 40506, USA.
| |
Collapse
|
12
|
Layek S, Banerjee P, Sarkar N. An insight into the dissolution of cellulose in 1-butyl-3-methylimidazolium chloride-DMSO binary Mixture: Exploring the dynamics of rhodamine 6G and fluorescein. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2021.116817] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
13
|
Lefroy KS, Murray BS, Ries ME. Rheological and NMR Studies of Cellulose Dissolution in the Ionic Liquid BmimAc. J Phys Chem B 2021; 125:8205-8218. [PMID: 34279933 DOI: 10.1021/acs.jpcb.1c02848] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Solutions of two types of cellulose in the ionic liquid 1-butyl-3-methyl-imidazolium acetate (BmimAc) have been analyzed using rheology and fast-field cycling nuclear magnetic resonance (NMR) spectroscopy, in order to analyze the macroscopic (bulk) and microscopic environments, respectively. The degree of polymerization (DP) was observed to have a significant effect on both the overlap (c*) and entanglement (ce) concentrations and the intrinsic viscosity ([η]). For microcrystalline cellulose (MCC)/BmimAc solutions, [η] = 116 mL g-1, which is comparable to that of MCC/1-ethyl-3-methyl-imidazolium acetate (EmimAc) solutions, while [η] = 350 mL g-1 for the commercial cellulose (higher DP). Self-diffusion coefficients (D) obtained via the model-independent approach were found to decrease with cellulose concentration and increase with temperature, which can in part be explained by the changes in viscosity; however, ion interactions on a local level are also important. Both Stokes-Einstein and Stokes-Einstein-Debye analyses were carried out to directly compare rheological and relaxometry analyses. It was found that polymer entanglements affect the microscopic environment to a much lesser extent than for the macroscopic environment. Finally, the temperature dependencies of η, D, and relaxation time (T1) could be well described by Arrhenius relationships, and thus, activation energies (Ea) for flow, diffusion, and relaxation were determined. We demonstrate that temperature and cellulose concentration have different effects on short- and long-range interactions.
Collapse
Affiliation(s)
- Katherine S Lefroy
- School of Food Science and Nutrition, University of Leeds, Leeds LS2 9JT, U.K
| | - Brent S Murray
- School of Food Science and Nutrition, University of Leeds, Leeds LS2 9JT, U.K
| | - Michael E Ries
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, U.K
| |
Collapse
|
14
|
Kahlon NK, Weber CC. Micellar Catalysis and Reactivity in Nanostructured Ionic Liquids: Two Sides of the Same Coin? Aust J Chem 2021. [DOI: 10.1071/ch21109] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
15
|
Sahoo DK, Chand A, Jena S, Biswal HS. Hydrogen-bond-driven thiouracil dissolution in aqueous ionic liquid: A combined microscopic, spectroscopic and molecular dynamics study. J Mol Liq 2020. [DOI: 10.1016/j.molliq.2020.114275] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
|
16
|
Isobe N, Shimizu S. Salt-induced LCST-type thermal gelation of methylcellulose: quantifying non-specific interactions via fluctuation theory. Phys Chem Chem Phys 2020; 22:15999-16006. [PMID: 32632420 DOI: 10.1039/d0cp01687j] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
What drives the phase separation of water-soluble polymers in the presence of electrolytes was quantified on a molecular scale via statistical thermodynamic fluctuation theory. Quantifying polymer-water and polymer-salt interactions enabled us to identify the dominant interaction for phase separation. As a model system, the lower critical solution temperature (LCST) type thermal gelation of methylcellulose (MC) in aqueous salt solutions was chosen. The Kirkwood-Buff integrals for intermolecular interactions, calculated from the published calorimetric and volumetric data, showed that (1) the accumulation of salts around MC molecules (favourable interaction between salts and MC) inhibits thermal gelation and the depletion of salts from MC (unfavourable interaction between salts and MC) promotes the gelation, and (2) this salt-MC interaction is the dominant factor (50-100 times stronger than the water-MC interaction). This insight from the fluctuation theory is at odds with the age-old consensus regarding the driving force of thermal gelation: water structure change in the presence of salts induces the promotion or inhibition of thermal gelation. However, our conclusion is founded upon the ability of the fluctuation theory to quantify water-MC and salt-MC interaction independently via the Kirkwood-Buff integrals. Flory-Huggins (FH) theory, on the contrary, could not separate these two interactions owing to the lack of a thermodynamic degree of freedom because the lattice solution is assumed to be fully packed. In addition, the dominant contribution from salt depletion poses difficulty for the χ parameter, which is essentially the difference of contact energies. Our approach, requiring calorimetric and volumetric data alone as input, provides a simple and versatile method towards elucidating the effect of cosolvents on biopolymer phase separation of physiological importance.
Collapse
Affiliation(s)
- Noriyuki Isobe
- Research Institute for Marine Resources Utilization, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), 2-15 Natsushima-cho, Yokosuka 237-0061, Japan.
| | - Seishi Shimizu
- York Structural Biology Laboratory, Department of Chemistry, University of York, Heslington, York, YO10 5DD, UK.
| |
Collapse
|
17
|
Blasius J, Elfgen R, Hollóczki O, Kirchner B. Glucose in dry and moist ionic liquid: vibrational circular dichroism, IR, and possible mechanisms. Phys Chem Chem Phys 2020; 22:10726-10737. [PMID: 32150178 DOI: 10.1039/c9cp06798a] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Ionic liquids and their mixtures with water show remarkable features in cellulose processing. For this reason, understanding the behavior of carbohydrates in ionic liquids is important. In the present study, we investigated three d-glucose isomers (α, β and open-chain) in 1-ethyl-3-methylimidazolium acetate in the presence and absence of water, through ab initio molecular dynamics simulations. In the complex hydrogen bonding network of these mixtures, the most interesting observation is that upon water addition every hydrogen bond elongates, except the glucose-glucose hydrogen bond for the open-chain and the α-form which shortens, clearly showing the beginning of the crystallization process. The ring glucose rearranges from on-top to in-plane and the open form changes from a coiled to a more linear arrangement when adding water which explains the contradiction that the center of mass distances of the glucose molecules with other glucose molecules grow while the hydrogen bonds shorten. The appearance of coiled open forms indicates that the previously suggested isomerization between these forms is possible and might play a role in the solubility of the related carbohydrates. The calculated IR and VCD spectra reveal insight into the intermolecular interactions, with good to excellent agreements with experimental spectra. Investigating the role of the cation, distances between the acidic carbon atom of the cation and the glucose carbon atom where ring closure and opening occurs are found, which are way shorter than dispersion-like interactions between aliphatic hydrocarbons.
Collapse
Affiliation(s)
- Jan Blasius
- Mulliken Center for Theoretical Chemistry, University of Bonn, Beringstraße 4 + 6, D-53115 Bonn, Germany.
| | | | | | | |
Collapse
|
18
|
Turner AH, Byrne EL, Pereira T, Holbrey JD. Enhanced extraction of phenol from model oils using ionic liquids elucidated with neutron diffraction. Phys Chem Chem Phys 2020; 22:10219-10226. [PMID: 32350490 DOI: 10.1039/d0cp01013h] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Aromatic cation ionic liquids (ILs) based on alkylpyridiniums are shown to be good phenol extractants from model oils (hexane/toluene). ILs with hard basic anions are found to have best extraction efficiency consistent with tetraalkylammonium salts ([NR4]X). Key extraction interactions were analysed using small angle neutron diffraction. Trifluoromethanesulphonate ([OTf]- or triflate) anions provide the synergistic effects of reduced cation-phenol centre of mass (COM) distances and increased hydrogen bonding that are linked to the improved extraction efficiency. Increases in cation electron density (methylpyridinium ([Me-Py]+) vs. methylpicolinium ([Me-3-Pic]+)) also reduce cation-phenol COM interaction lengths consistent with small increases in extraction efficiency for the same ionic liquids.
Collapse
Affiliation(s)
- Adam H Turner
- The QUILL Research Centre, School of Chemistry and Chemical Engineering, Queen's University Belfast, Belfast BT9 5AG, UK. and Department of Chemistry, Ateneo de Manila University, Quezon City 1108, Philippines.
| | - Emily L Byrne
- The QUILL Research Centre, School of Chemistry and Chemical Engineering, Queen's University Belfast, Belfast BT9 5AG, UK.
| | - Thaise Pereira
- The QUILL Research Centre, School of Chemistry and Chemical Engineering, Queen's University Belfast, Belfast BT9 5AG, UK.
| | - John D Holbrey
- The QUILL Research Centre, School of Chemistry and Chemical Engineering, Queen's University Belfast, Belfast BT9 5AG, UK.
| |
Collapse
|
19
|
Insight into the interaction between arabinoxylan and imidazolium acetate-based ionic liquids. Carbohydr Polym 2020; 231:115699. [PMID: 31888847 DOI: 10.1016/j.carbpol.2019.115699] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2019] [Revised: 10/26/2019] [Accepted: 11/30/2019] [Indexed: 11/23/2022]
Abstract
Herein, six ionic liquids (ILs) with different cations and the same anion of acetate (Ac-) were used to dissolve arabinoxylan. These ILs included N-methylimidazolium acetate (HmimAc), 1-ethyl-3-methylimidazolium acetate (EmimAc), 1-hydroxyethyl-3-methylimidazolium acetate (HOemimAc), 1-propyl-3-methylimidazolium acetate (PrmimAc), 1-allyl-3-methylimidazolium acetate (AmimAc), and 1-butyl-3-methylimidazolium acetate (BmimAc). The solubilities of arabinoxylan in these ILs were determined, and the dissolution mechanism was explained using 1H and 13C NMR techniques. The solubilities of arabinoxylan in the ILs were in the order: BmimAc > EmimAc > AmimAc > PrmimAc > HOemimAc > HmimAc. Both the cation and Ac- played an important role in the solubilization of arabinoxylan, but Ac- performed the major factor. The structure of cation greatly affected the hydrogen bond accepting ability of Ac-. Increasing the mass ratio of arabinoxylan to ILs resulted in stronger hydrogen bond between arabinoxylan and the ILs. Both the solubility and the strength of hydrogen-bonding interaction between arabinoxylan and the ILs decreased in the recycled ILs because of the impurities remained.
Collapse
|
20
|
The Nanofication and Functionalization of Bacterial Cellulose and Its Applications. NANOMATERIALS 2020; 10:nano10030406. [PMID: 32106515 PMCID: PMC7152840 DOI: 10.3390/nano10030406] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 02/17/2020] [Accepted: 02/21/2020] [Indexed: 01/24/2023]
Abstract
Since economic and environmental issues have become critical in the last several years, the amount of sustainable bio-based production has increased. In this article, microbial polysaccharides, including bacterial cellulose (BC), are analyzed as promising resources with the potential for applications in biofields and non-biofields. Many scientists have established various methods of BC production, nanofication, and functionalization. In particular, this review will address the essential advances in recent years focusing on nanofication methods and nanoficated BC applications as well as functionalization methods and functionalized BC applications.
Collapse
|
21
|
Zhou Y, Xu X, Wang Z, Gong S, Chen H, Yu Z, Kiefer J. The effect of introducing an ether group into an imidazolium-based ionic liquid in binary mixtures with DMSO. Phys Chem Chem Phys 2020; 22:15734-15742. [DOI: 10.1039/d0cp01568g] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Combined DFT and FTIR investigations reveal interesting hydrogen bonding interactions between dimethyl sulfoxide and an ether-functionalized imidazolium-based ionic liquid.
Collapse
Affiliation(s)
- Yu Zhou
- Shandong Sino-Japanese Center for Collaborative Research of Carbon Nanomaterials
- College of Chemistry and Chemical Engineering
- Qingdao University
- Qingdao 266071
- China
| | - Xianzhen Xu
- Shandong Sino-Japanese Center for Collaborative Research of Carbon Nanomaterials
- College of Chemistry and Chemical Engineering
- Qingdao University
- Qingdao 266071
- China
| | - Zonghua Wang
- Shandong Sino-Japanese Center for Collaborative Research of Carbon Nanomaterials
- College of Chemistry and Chemical Engineering
- Qingdao University
- Qingdao 266071
- China
| | - Shida Gong
- Shandong Sino-Japanese Center for Collaborative Research of Carbon Nanomaterials
- College of Chemistry and Chemical Engineering
- Qingdao University
- Qingdao 266071
- China
| | - Hong Chen
- Shandong Sino-Japanese Center for Collaborative Research of Carbon Nanomaterials
- College of Chemistry and Chemical Engineering
- Qingdao University
- Qingdao 266071
- China
| | - Zhiwu Yu
- MOE Key Laboratory of Bioorganic Phosphorous Chemistry and Chemical Biology
- Tsinghua University
- Beijing 100084
- China
| | | |
Collapse
|
22
|
Moura L, Gilmore M, Callear SK, Youngs TGA, Holbrey JD. Solution structure of propane and propene dissolved in the ionic liquid 1-butyl-3-methylimidazolium bis{(trifluoromethyl)sulfonyl}imide from neutron diffraction with H/D substitution and empirical potential structure refinement modelling. Mol Phys 2019. [DOI: 10.1080/00268976.2019.1649495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Leila Moura
- QUILL Research Centre, School of Chemistry and Chemical Engineering, Queen's University Belfast, Belfast, UK
| | - Mark Gilmore
- QUILL Research Centre, School of Chemistry and Chemical Engineering, Queen's University Belfast, Belfast, UK
| | | | | | - John D. Holbrey
- QUILL Research Centre, School of Chemistry and Chemical Engineering, Queen's University Belfast, Belfast, UK
| |
Collapse
|
23
|
|
24
|
Winters J, Dehaen W, Binnemans K. Solvation structure of poly-m-phenyleneisophthalamide (PMIA) in ionic liquids. Phys Chem Chem Phys 2019; 21:4053-4062. [PMID: 30714587 DOI: 10.1039/c8cp07041e] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Polyaramids are a class of high-performance polymers, known for their high mechanical strength and chemical and thermal stability. Their ability to create a network of intermolecular hydrogen bonds causes them to be very poorly soluble in conventional solvents. Hazardous solvents such as N-methylpyrrolidone (NMP) and dimethylacetamide (DMA), in combination with an inorganic salt such as CaCl2, are currently used for the synthesis and processing of polyaramids. Ionic liquids are proposed as suitable greener alternatives. In this work, we studied the solubility and dissolution mechanism of the meta-oriented polyaramid poly-m-phenyleneisophthalamide (PMIA) in a wide range of ionic liquids. It was found that, similarly to cellulose, PMIA could be dissolved readily and in large amounts in ionic liquids containing a strongly coordinating anion (such as chloride, acetate and dialkylphosphate) and an imidazolium cation. Hydrogen bonding between the anion and the amide NH of PMIA is the main solvent-solute interaction. An odd-even effect in solubility occurred when altering the length of the side chains on the imidazolium cation. Furthermore, it was found that the presence of hydrogen bond donating CH moieties on the cation is a necessary condition for dissolution. The exact role of these hydrogen bond donors was investigated by FTIR and 13C NMR spectroscopy. It was found that there is no significant interaction between the hydrogen atoms of the imidazolium ring and the amide carbonyl groups. Rather, the hydrogen bond donors are needed to stabilize the solvation shell around PMIA through alternating cation-anion interactions.
Collapse
Affiliation(s)
- Jonas Winters
- KU Leuven, Department of Chemistry, Celestijnenlaan 200F, P.O. Box 2404, B-3001 Heverlee, Belgium.
| | | | | |
Collapse
|
25
|
Brehm M, Sebastiani D. Simulating structure and dynamics in small droplets of 1-ethyl-3-methylimidazolium acetate. J Chem Phys 2018; 148:193802. [PMID: 30307180 DOI: 10.1063/1.5010342] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
To investigate the structure and dynamics of small ionic liquid droplets in gas phase, we performed a DFT-based ab initio molecular dynamics study of several 1-ethyl-3-methylimidazolium acetate clusters in vacuum as well as a bulk phase simulation. We introduce an unbiased criterion for average droplet diameter and density. By extrapolation of the droplet densities, we predict the experimental bulk phase density with a deviation of only a few percent. The hydrogen bond geometry between cations and anions is very similar in droplets and bulk, but the hydrogen bond dynamics is significantly slower in the droplets, becoming slower with increasing system size, with hydrogen bond lifetimes up to 2000 ps. From a normal mode analysis of the trajectories, we identify the modes of the ring proton C-H stretching, which are strongly affected by hydrogen bonding. From analyzing these, we find that the hydrogen bond becomes weaker with increasing system size. The cations possess an increased concentration inside the clusters, whereas the anions show an excess concentration on the outside. Almost all anions point towards the droplet center with their carboxylic groups. Ring stacking is found to be a very important structural motif in the droplets (as in the bulk), but side chain interactions are only of minor importance. By using Voronoi tessellation, we define the exposed droplet surface and find that it consists mainly of hydrogen atoms from the cation's and anion's methyl and ethyl groups. Polar atoms are rarely found on the surface, such that the droplets appear completely hydrophobic on the outside.
Collapse
Affiliation(s)
- Martin Brehm
- Institut für Chemie-Theoretische Chemie, Martin-Luther-Universität Halle-Wittenberg, Von-Danckelmann-Platz 4, 06120 Halle (Saale), Germany
| | - Daniel Sebastiani
- Institut für Chemie-Theoretische Chemie, Martin-Luther-Universität Halle-Wittenberg, Von-Danckelmann-Platz 4, 06120 Halle (Saale), Germany
| |
Collapse
|
26
|
Raghuwanshi VS, Cohen Y, Garnier G, Garvey CJ, Russell RA, Darwish T, Garnier G. Cellulose Dissolution in Ionic Liquid: Ion Binding Revealed by Neutron Scattering. Macromolecules 2018. [DOI: 10.1021/acs.macromol.8b01425] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Vikram Singh Raghuwanshi
- Bioresource Processing Research Institute of Australia (BioPRIA), Department of Chemical Engineering, Monash University, Clayton, Victoria 3800, Australia
| | - Yachin Cohen
- Department of Chemical Engineering, Technion-Israel Institute of Technology, Haifa 3200003, Israel
| | - Guillaume Garnier
- Bioresource Processing Research Institute of Australia (BioPRIA), Department of Chemical Engineering, Monash University, Clayton, Victoria 3800, Australia
| | - Christopher J. Garvey
- Australian Nuclear Science and Technology Organisation (ANSTO), New Illawarra Rd., Lucas Heights, NSW 2234, Australia
| | - Robert A. Russell
- Australian Nuclear Science and Technology Organisation (ANSTO), New Illawarra Rd., Lucas Heights, NSW 2234, Australia
| | - Tamim Darwish
- Australian Nuclear Science and Technology Organisation (ANSTO), New Illawarra Rd., Lucas Heights, NSW 2234, Australia
| | - Gil Garnier
- Bioresource Processing Research Institute of Australia (BioPRIA), Department of Chemical Engineering, Monash University, Clayton, Victoria 3800, Australia
| |
Collapse
|
27
|
Xu A, Chen L, Wang J. Functionalized Imidazalium Carboxylates for Enhancing Practical Applicability in Cellulose Processing. Macromolecules 2018. [DOI: 10.1021/acs.macromol.8b00724] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- Airong Xu
- School of Chemical Engineering and Pharmaceutics, Henan University of Science and Technology, Luoyang, Henan 471003, P. R. China
| | - Lin Chen
- School of Chemical Engineering and Pharmaceutics, Henan University of Science and Technology, Luoyang, Henan 471003, P. R. China
| | - Jianji Wang
- School of Chemistry and Chemical Engineering, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, Henan Normal University, Xinxiang, Henan 453007, P. R. China
| |
Collapse
|
28
|
Li Y, Wang J, Liu X, Zhang S. Towards a molecular understanding of cellulose dissolution in ionic liquids: anion/cation effect, synergistic mechanism and physicochemical aspects. Chem Sci 2018; 9:4027-4043. [PMID: 29780532 PMCID: PMC5941279 DOI: 10.1039/c7sc05392d] [Citation(s) in RCA: 98] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 03/25/2018] [Indexed: 12/23/2022] Open
Abstract
This perspective summarizes mechanistic studies on cellulose dissolution in ionic liquids, highlighting the synergistic mechanism, physicochemical aspects and future research trends.
Cellulose is one of the most abundant bio-renewable materials on the earth and its conversion to biofuels provides an appealing way to satisfy the increasing global energy demand. However, before carrying out the process of enzymolysis to glucose or polysaccharides, cellulose needs to be pretreated to overcome its recalcitrance. In recent years, a variety of ionic liquids (ILs) have been found to be effective solvents for cellulose, providing a new, feasible pretreatment strategy. A lot of experimental and computational studies have been carried out to investigate the dissolution mechanism. However, many details are not fully understood, which highlights the necessity to overview the current knowledge of cellulose dissolution and identify the research trend in the future. This perspective summarizes the mechanistic studies and microscopic insights of cellulose dissolution in ILs. Recent investigations of the synergistic effect of cations/anions and the distinctive structural changes of cellulose microfibril in ILs are also reviewed. Besides, understanding the factors controlling the dissolution process, such as the structure of anions/cations, viscosity of ILs, pretreatment temperature, heating rate, etc., has been discussed from a structural and physicochemical viewpoint. At the end, the existing problems are discussed and future prospects are given. We hope this article would be helpful for deeper understanding of the cellulose dissolution process in ILs and the rational design of more efficient and recyclable ILs.
Collapse
Affiliation(s)
- Yao Li
- Beijing Key Laboratory of Ionic Liquids Clean Process , CAS Key Laboratory of Green Process and Engineering , Institute of Process Engineering , Chinese Academy of Sciences , Beijing , 100190 , P. R. China . ;
| | - Jianji Wang
- Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals , School of Chemistry and Chemical Engineering , Key Laboratory of Green Chemical Media and Reactions , Henan Normal University , Xinxiang , Henan 453007 , P. R. China
| | - Xiaomin Liu
- Beijing Key Laboratory of Ionic Liquids Clean Process , CAS Key Laboratory of Green Process and Engineering , Institute of Process Engineering , Chinese Academy of Sciences , Beijing , 100190 , P. R. China . ;
| | - Suojiang Zhang
- Beijing Key Laboratory of Ionic Liquids Clean Process , CAS Key Laboratory of Green Process and Engineering , Institute of Process Engineering , Chinese Academy of Sciences , Beijing , 100190 , P. R. China . ;
| |
Collapse
|
29
|
D'Agostino C, Mantle MD, Mullan CL, Hardacre C, Gladden LF. Diffusion, Ion Pairing and Aggregation in 1-Ethyl-3-Methylimidazolium-Based Ionic Liquids Studied by 1
H and 19
F PFG NMR: Effect of Temperature, Anion and Glucose Dissolution. Chemphyschem 2018; 19:1081-1088. [DOI: 10.1002/cphc.201701354] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Indexed: 11/06/2022]
Affiliation(s)
- Carmine D'Agostino
- Department of Chemical Engineering and Biotechnology; University of Cambridge, Philippa Fawcett Drive; West Cambridge Site Cambridge CB3 0AS UK
- School of Chemical Engineering and Analytical Science; The University of Manchester; The Mill, Sackville Street Manchester M13 9PL UK
| | - Mick D. Mantle
- Department of Chemical Engineering and Biotechnology; University of Cambridge, Philippa Fawcett Drive; West Cambridge Site Cambridge CB3 0AS UK
| | - Claire L. Mullan
- School of Chemistry and Chemical Engineering; Queen's University Belfast; Belfast BT9 5AG UK
| | - Christopher Hardacre
- School of Chemistry and Chemical Engineering; Queen's University Belfast; Belfast BT9 5AG UK
- School of Chemical Engineering and Analytical Science; The University of Manchester; The Mill, Sackville Street Manchester M13 9PL UK
| | - Lynn F. Gladden
- Department of Chemical Engineering and Biotechnology; University of Cambridge, Philippa Fawcett Drive; West Cambridge Site Cambridge CB3 0AS UK
| |
Collapse
|
30
|
Turner AH, Imberti S, Swadźba-Kwaśny M, Holbrey JD. Applying neutron diffraction with isotopic substitution to the structure and proton-transport pathways in protic imidazolium bis{(trifluoromethyl)sulfonyl}imide ionic liquids. Faraday Discuss 2018; 206:247-263. [DOI: 10.1039/c7fd00143f] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Neutron diffraction with isotopic substitution has been applied to examine the potential for complex-ion formation in protic imidazolium bis{(trifluoromethyl)sulfonyl}imide ionic liquids.
Collapse
Affiliation(s)
- Adam H. Turner
- School of Chemistry and Chemical Engineering
- The Queen’s University of Belfast
- Belfast
- UK
| | - Silvia Imberti
- ISIS
- Rutherford Appleton Laboratory
- Harwell Science & Innovation Campus
- Didcot
- UK
| | | | - John D. Holbrey
- School of Chemistry and Chemical Engineering
- The Queen’s University of Belfast
- Belfast
- UK
| |
Collapse
|
31
|
Uto T, Yamamoto K, Kadokawa JI. Cellulose Crystal Dissolution in Imidazolium-Based Ionic Liquids: A Theoretical Study. J Phys Chem B 2017; 122:258-266. [DOI: 10.1021/acs.jpcb.7b09525] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Takuya Uto
- Department of Chemistry,
Biotechnology, and Chemical Engineering, Graduate School of Science
and Engineering, Kagoshima University, 1-21-40 Korimoto, Kagoshima 890-0065, Japan
| | - Kazuya Yamamoto
- Department of Chemistry,
Biotechnology, and Chemical Engineering, Graduate School of Science
and Engineering, Kagoshima University, 1-21-40 Korimoto, Kagoshima 890-0065, Japan
| | - Jun-ichi Kadokawa
- Department of Chemistry,
Biotechnology, and Chemical Engineering, Graduate School of Science
and Engineering, Kagoshima University, 1-21-40 Korimoto, Kagoshima 890-0065, Japan
| |
Collapse
|
32
|
Maurya R, Naithani S, Bandyopadhyay D, Choudhury N, Dutt GB. Is Solute Rotation in an Ionic Liquid Influenced by the Addition of Glucose? J Phys Chem B 2017; 121:10965-10973. [PMID: 29125769 DOI: 10.1021/acs.jpcb.7b09888] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Fluorescence anisotropy measurements and molecular dynamics (MD) simulations have been performed to understand the specific interactions of two structurally similar nondipolar solutes, 2,5-dimethyl-1,4-dioxo-3,6-diphenylpyrrolo[3,4-c]pyrrole (DMDPP) and 1,4-dioxo-3,6-diphenylpyrrolo[3,4-c]pyrrole (DPP), with neat 1-butyl-3-methylimidazolium dicyanamide ([BMIM][N(CN)2]) and also in the presence of glucose. It has been observed that the measured reorientation times of DMDPP in neat [BMIM][N(CN)2] follow the predictions of the Stokes-Einstein-Debye hydrodynamic theory with slip boundary condition. Addition of glucose (0.075 and 0.15 mole fraction) has no bearing on the rotational diffusion of the solute apart from the viscosity related effects. In contrast, the reorientation times of DPP in neat [BMIM][N(CN)2] obey stick boundary condition as the hydrogen bond donating solute experiences specific interactions with the dicyanamide anion. No influence of the additive can be noticed on the rotational diffusion of DPP at 0.075 mole fraction of glucose. However, at 0.15 mole fraction of glucose, the reorientation times of the solute at a given viscosity and temperature decrease by 15-40% compared to those obtained in the neat ionic liquid. MD simulations indicate that each DPP molecule hydrogen bonds with two dicyanamide anions in neat ionic liquid. The simulations also reveal that, at 0.15 mole fraction of glucose, the concentration of anions hydrogen bonded to glucose increases significantly; therefore, the percentage of solute molecules that can form hydrogen bonds with two dicyanamide anions decreases to 84, which leads to faster rotation of DPP.
Collapse
Affiliation(s)
- Rajan Maurya
- Atma Ram Sanatan Dharma College , Dhaula Kuan, New Delhi 110 021, India
| | | | | | | | | |
Collapse
|
33
|
Zhong C, Cheng F, Zhu Y, Gao Z, Jia H, Wei P. Dissolution mechanism of cellulose in quaternary ammonium hydroxide: Revisiting through molecular interactions. Carbohydr Polym 2017; 174:400-408. [DOI: 10.1016/j.carbpol.2017.06.078] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Revised: 06/12/2017] [Accepted: 06/20/2017] [Indexed: 11/24/2022]
|
34
|
Hirosawa K, Fujii K, Hashimoto K, Shibayama M. Solvated Structure of Cellulose in a Phosphonate-Based Ionic Liquid. Macromolecules 2017. [DOI: 10.1021/acs.macromol.7b01138] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Kazu Hirosawa
- Institute
for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581, Japan
| | - Kenta Fujii
- Graduate
School of Sciences and Technology for Innovation, Yamaguchi University, 2-16-1 Tokiwadai,
Ube, Yamaguchi 755-8611, Japan
| | - Kei Hashimoto
- Department
of Chemistry and Biotechnology, Yokohama National University, 79-5 Tokiwadai,
Hodogaya-ku, Yokohama 240-8501, Japan
| | - Mitsuhiro Shibayama
- Institute
for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581, Japan
| |
Collapse
|
35
|
Room-temperature ionic liquids meet bio-membranes: the state-of-the-art. Biophys Rev 2017; 9:309-320. [PMID: 28779453 DOI: 10.1007/s12551-017-0279-1] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Accepted: 07/12/2017] [Indexed: 10/19/2022] Open
Abstract
Room-temperature ionic liquids (RTIL) are a new class of organic salts whose melting temperature falls below the conventional limit of 100 °C. Their low vapor pressure, moreover, has made these ionic compounds the solvents of choice of the so-called green chemistry. For these and other peculiar characteristics, they are increasingly used in industrial applications. However, studies of their interaction with living organisms have highlighted mild to severe health hazards. Since their cytotoxicity shows a positive correlation with their lipophilicity, several chemical-physical studies of their interactions with biomembranes have been carried out in the last few years, aiming to identify the molecular mechanisms behind their toxicity. Cation chain length and anion nature of RTILs have seemed to affect lipophilicity and, in turn, their toxicity. However, the emerging picture raises new questions, points to the need to assess toxicity on a case-by-case basis, but also suggests a potential positive role of RTILs in pharmacology, bio-medicine and bio-nanotechnology. Here, we review this new subject of research, and comment on the future and the potential importance of this emerging field of study.
Collapse
|
36
|
Hammond OS, Bowron DT, Jackson AJ, Arnold T, Sanchez-Fernandez A, Tsapatsaris N, Garcia Sakai V, Edler KJ. Resilience of Malic Acid Natural Deep Eutectic Solvent Nanostructure to Solidification and Hydration. J Phys Chem B 2017; 121:7473-7483. [DOI: 10.1021/acs.jpcb.7b05454] [Citation(s) in RCA: 103] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Oliver S. Hammond
- Centre
for Sustainable Chemical Technologies, University of Bath, Claverton Down, Bath BA2
7AY, U.K
- Department
of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, U.K
| | - Daniel T. Bowron
- ISIS
Neutron and Muon Source, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Didcot OX11 0QX, U.K
| | - Andrew J. Jackson
- European Spallation
Source, Box 176, 221 00 Lund, Sweden
- Division
of Physical Chemistry, Department of Chemistry, Lund University, Box
124, 221 00 Lund, Sweden
| | - Thomas Arnold
- Diamond
Light Source, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Didcot OX11 0QX, U.K
| | | | | | - Victoria Garcia Sakai
- ISIS
Neutron and Muon Source, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Didcot OX11 0QX, U.K
| | - Karen J. Edler
- Centre
for Sustainable Chemical Technologies, University of Bath, Claverton Down, Bath BA2
7AY, U.K
- Department
of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, U.K
| |
Collapse
|
37
|
Kan Z, Zhu Q, Yang L, Huang Z, Jin B, Ma J. Polarization Effects on the Cellulose Dissolution in Ionic Liquids: Molecular Dynamics Simulations with Polarization Model and Integrated Tempering Enhanced Sampling Method. J Phys Chem B 2017; 121:4319-4332. [DOI: 10.1021/acs.jpcb.6b12647] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Zigui Kan
- School
of Chemistry and Chemical Engineering, Key Laboratory of Mesoscopic
Chemistry of MOE, Nanjing University, Nanjing 210093, People’s Republic of China
- School
of Sciences, China Pharmaceutical University, Nanjing 211198, People’s Republic of China
| | - Qiang Zhu
- School
of Chemistry and Chemical Engineering, Key Laboratory of Mesoscopic
Chemistry of MOE, Nanjing University, Nanjing 210093, People’s Republic of China
| | - Lijiang Yang
- Institute
of Theoretical and Computational Chemistry, College of Chemistry and
Molecular Engineering, Peking University, Beijing 100871, People’s Republic of China
| | - Zhixiong Huang
- Research
Institute of Superconductor Electronics (RISE), School of Electronic
Science and Engineering, Nanjing University, Nanjing 210093, People’s Republic of China
| | - Biaobing Jin
- Research
Institute of Superconductor Electronics (RISE), School of Electronic
Science and Engineering, Nanjing University, Nanjing 210093, People’s Republic of China
| | - Jing Ma
- School
of Chemistry and Chemical Engineering, Key Laboratory of Mesoscopic
Chemistry of MOE, Nanjing University, Nanjing 210093, People’s Republic of China
| |
Collapse
|
38
|
Gehrke S, Schmitz K, Hollóczki O. Is Carbene Formation Necessary for Dissolving Cellulose in Ionic Liquids? J Phys Chem B 2017; 121:4521-4529. [DOI: 10.1021/acs.jpcb.7b00631] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Sascha Gehrke
- Mulliken
Center for Theoretical Chemistry, University of Bonn, Beringstr. 4 + 6, D-53115 Bonn, Germany
- Max Planck Institute for Chemical Energy Conversion, Stiftstr. 34-36, D-45470 Muelheim an der Ruhr, Germany
| | - Karola Schmitz
- Mulliken
Center for Theoretical Chemistry, University of Bonn, Beringstr. 4 + 6, D-53115 Bonn, Germany
| | - Oldamur Hollóczki
- Mulliken
Center for Theoretical Chemistry, University of Bonn, Beringstr. 4 + 6, D-53115 Bonn, Germany
| |
Collapse
|
39
|
Soper AK, Edler KJ. Coarse-grained empirical potential structure refinement: Application to a reverse aqueous micelle. Biochim Biophys Acta Gen Subj 2017; 1861:1652-1660. [PMID: 28259740 DOI: 10.1016/j.bbagen.2017.02.028] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 02/24/2017] [Accepted: 02/25/2017] [Indexed: 10/20/2022]
Abstract
Conventional atomistic computer simulations, involving perhaps up to 106atoms, can achieve length-scales on the order of a few 10s of nm. Yet many heterogeneous systems, such as colloids, nano-structured materials, or biological systems, can involve correlations over distances up 100s of nm, perhaps even 1μm in some instances. For such systems it is necessary to invoke coarse-graining, where single atoms are replaced by agglomerations of atoms, usually represented as spheres, in order for the simulation to be performed within a practical computer memory and time scale. Small angle scattering and reflectivity measurements, both X-ray and neutron, are routinely used to investigate structure in these systems, and traditionally the data have been interpreted in terms of discrete objects, such as spheres, sheets, and cylinders, and combinations thereof. Here we combine the coarse-grained computer simulation approach with neutron small angle scattering to refine the structure of a heterogeneous system, in the present case a reverse aqueous micelle of sodium-dioctyl sulfosuccinate (AOT) and iso-octane. The method closely follows empirical potential structure refinement and involves deriving an empirical interaction potential from the scattering data. As in traditional coarse-grained methods, individual atoms are replaced by spherical density profiles, which, unlike real atoms, can inter-penetrate to a significant extent. The method works over an arbitrary range of length-scales, but is limited to around 2 orders of magnitude in distance above a specified dimension. The smallest value for this dimension is of order 1nm, but the largest dimension is arbitrary. This article is part of a Special Issue entitled "Recent Advances in Bionanomaterials" Guest Editor: Dr. Marie-Louise Saboungi and Dr. Samuel D. Bader.
Collapse
Affiliation(s)
- A K Soper
- STFC Rutherford Appleton Laboratory, Harwell Campus, Didcot, OX11 0QX, UK.
| | - K J Edler
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK
| |
Collapse
|
40
|
Endo T, Hosomi S, Fujii S, Ninomiya K, Takahashi K. Nano-Structural Investigation on Cellulose Highly Dissolved in Ionic Liquid: A Small Angle X-ray Scattering Study. Molecules 2017; 22:E178. [PMID: 28117730 PMCID: PMC6155725 DOI: 10.3390/molecules22010178] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 01/12/2017] [Accepted: 01/18/2017] [Indexed: 11/17/2022] Open
Abstract
We investigated nano-structural changes of cellulose dissolved in 1-ethyl-3-methylimidazolium acetate-an ionic liquid (IL)-using a small angle X-ray scattering (SAXS) technique over the entire concentration range (0-100 mol %). Fibril structures of cellulose disappeared at 40 mol % of cellulose, which is a significantly higher concentration than the maximum concentration of dissolution (24-28 mol %) previously determined in this IL. This behavior is explained by the presence of the anion bridging, whereby an anion prefers to interact with multiple OH groups of different cellulose molecules at high concentrations, discovered in our recent work. Furthermore, we observed the emergence of two aggregated nano-structures in the concentration range of 30-80 mol %. The diameter of one structure was 12-20 nm, dependent on concentration, which is ascribed to cellulose chain entanglement. In contrast, the other with 4.1 nm diameter exhibited concentration independence and is reminiscent of a cellulose microfibril, reflecting the occurrence of nanofibrillation. These results contribute to an understanding of the dissolution mechanism of cellulose in ILs. Finally, we unexpectedly proposed a novel cellulose/IL composite: the cellulose/IL mixtures of 30-50 mol % that possess liquid crystallinity are sufficiently hard to be moldable.
Collapse
Affiliation(s)
- Takatsugu Endo
- Faculty of Natural System, Institute of Science and Engineering, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan.
| | - Shota Hosomi
- Faculty of Natural System, Institute of Science and Engineering, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan.
| | - Shunsuke Fujii
- Faculty of Natural System, Institute of Science and Engineering, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan.
| | - Kazuaki Ninomiya
- Institute for Frontier Science Initiative, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan.
| | - Kenji Takahashi
- Faculty of Natural System, Institute of Science and Engineering, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan.
| |
Collapse
|
41
|
Russina O, Triolo A. Ionic Liquids and Neutron Scattering. NEUTRON SCATTERING - APPLICATIONS IN BIOLOGY, CHEMISTRY, AND MATERIALS SCIENCE 2017. [DOI: 10.1016/b978-0-12-805324-9.00004-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
|
42
|
Endo T, Hosomi S, Fujii S, Ninomiya K, Takahashi K. Anion Bridging-Induced Structural Transformation of Cellulose Dissolved in Ionic Liquid. J Phys Chem Lett 2016; 7:5156-5161. [PMID: 27973881 DOI: 10.1021/acs.jpclett.6b02504] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We performed structural investigations of cellulose mixed with 1-ethyl-3-methylimidazolium acetate ([Emim][OAc]) in the entire concentration range (0-100 mol %) by wide-angle X-ray scattering with the aid of quantum chemical calculations and 13C solid-state NMR spectroscopy. We particularly focused on a highly concentrated region (≥30 mol %), which has previously been overlooked. At concentrations of 15-30 mol %, a periodic peak corresponding to cellulose chain alignment emerged; this is associated with a lyotropic cholesteric liquid-crystalline phase. At concentrations of ≥30 mol %, the structure is transformed into ordered layers where OAc anions and Emim cations intercalate. This transformation is found to be driven by a change in the interaction between the IL anions and the OH groups of cellulose. At low concentrations, the anion mainly interacts with the OH group of cellulose in a 1:1 ratio, as previously reported; at high concentrations, the anions bridge the OH groups of two cellulose chains.
Collapse
Affiliation(s)
- Takatsugu Endo
- Faculty of Natural System, Institute of Science and Engineering and ‡Institute for Frontier Science Initiative, Kanazawa University , Kakuma-machi, Kanazawa 920-1192, Japan
| | - Shota Hosomi
- Faculty of Natural System, Institute of Science and Engineering and ‡Institute for Frontier Science Initiative, Kanazawa University , Kakuma-machi, Kanazawa 920-1192, Japan
| | - Shunsuke Fujii
- Faculty of Natural System, Institute of Science and Engineering and ‡Institute for Frontier Science Initiative, Kanazawa University , Kakuma-machi, Kanazawa 920-1192, Japan
| | - Kazuaki Ninomiya
- Faculty of Natural System, Institute of Science and Engineering and ‡Institute for Frontier Science Initiative, Kanazawa University , Kakuma-machi, Kanazawa 920-1192, Japan
| | - Kenji Takahashi
- Faculty of Natural System, Institute of Science and Engineering and ‡Institute for Frontier Science Initiative, Kanazawa University , Kakuma-machi, Kanazawa 920-1192, Japan
| |
Collapse
|
43
|
Singh V, Banipal PK, Gardas RL, Banipal TS. Speed of sound and apparent molar isentropic compression of 1-butyl-3-methylimidazolium bromide in aqueous monosaccharide solutions. J Mol Liq 2016. [DOI: 10.1016/j.molliq.2016.08.022] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
44
|
Norman SE, Turner AH, Holbrey JD, Youngs TGA. Solvation Structure of Uracil in Ionic Liquids. Chemphyschem 2016; 17:3923-3931. [PMID: 27643394 DOI: 10.1002/cphc.201600984] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Indexed: 11/12/2022]
Abstract
The local solvation environment of uracil dissolved in the ionic liquid 1-ethyl-3-methylimidazolium acetate has been studied using neutron diffraction techniques. At solvent:solute (ionic liquid:uracil) ratios of 3:1 and 2:1, little perturbation of the ion-ion correlations compared to those of the neat ionic liquid are observed. We find that solvation of the uracil is driven predominantly by the acetate anion of the solvent. While short distance correlations exist between uracil and the imidazolium cation, the geometry of these contacts suggest that they cannot be considered as hydrogen bonds, in contrast to other studies by Araújo et al. (J. M. Araújo, A. B. Pereiro, J. N. Canongia-Lopes, L. P. Rebelo, I. M. Marrucho, J. Phys. Chem. B 2013, 117, 4109-4120). Nevertheless, this combination of interactions of the solute with both the cation and anion components of the solvents helps explain the high solubility of the nucleobase in this media. In addition, favourable uracil-uracil contacts are observed, of similar magnitude to those between cation and uracil, and are also likely to aid dissolution.
Collapse
Affiliation(s)
- Sarah E Norman
- ISIS Facility, STFC Rutherford Appleton Laboratory, Harwell Campus, Didcot, Oxfordshire, OX11 0QX, UK.,School of Chemistry and Chemical Engineering, David Keir Building, Queen's University Belfast, Belfast, Northern Ireland, BT9 5AG, UK
| | - Adam H Turner
- School of Chemistry and Chemical Engineering, David Keir Building, Queen's University Belfast, Belfast, Northern Ireland, BT9 5AG, UK
| | - John D Holbrey
- School of Chemistry and Chemical Engineering, David Keir Building, Queen's University Belfast, Belfast, Northern Ireland, BT9 5AG, UK
| | - Tristan G A Youngs
- ISIS Facility, STFC Rutherford Appleton Laboratory, Harwell Campus, Didcot, Oxfordshire, OX11 0QX, UK
| |
Collapse
|
45
|
Understanding cellulose dissolution: effect of the cation and anion structure of ionic liquids on the solubility of cellulose. Sci China Chem 2016. [DOI: 10.1007/s11426-016-0269-5] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
46
|
Batista MLS, Passos H, Henriques BJM, Maginn EJ, Pinho SP, Freire MG, Gomes JRB, Coutinho JAP. Why are some cyano-based ionic liquids better glucose solvents than water? Phys Chem Chem Phys 2016; 18:18958-70. [PMID: 27353302 DOI: 10.1039/c6cp02538b] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Among different classes of ionic liquids (ILs), those with cyano-based anions have been of special interest due to their low viscosity and enhanced solvation ability for a large variety of compounds. Experimental results from this work reveal that the solubility of glucose in some of these ionic liquids may be higher than in water - a well-known solvent with enhanced capacity to dissolve mono- and disaccharides. This raises questions on the ability of cyano groups to establish strong hydrogen bonds with carbohydrates and on the optimal number of cyano groups at the IL anion that maximizes the solubility of glucose. In addition to experimental solubility data, these questions are addressed in this study using a combination of density functional theory (DFT) and molecular dynamics (MD) simulations. Through the calculation of the number of hydrogen bonds, coordination numbers, energies of interaction and radial and spatial distribution functions, it was possible to explain the experimental results and to show that the ability to favorably interact with glucose is driven by the polarity of each IL anion, with the optimal anion being dicyanamide.
Collapse
Affiliation(s)
- Marta L S Batista
- CICECO - Aveiro Institute of Materials, Department of Chemistry, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal.
| | | | | | | | | | | | | | | |
Collapse
|
47
|
Lenton S, Walsh DL, Rhys NH, Soper AK, Dougan L. Structural evidence for solvent-stabilisation by aspartic acid as a mechanism for halophilic protein stability in high salt concentrations. Phys Chem Chem Phys 2016; 18:18054-62. [PMID: 27327567 DOI: 10.1039/c6cp02684b] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Halophilic organisms have adapted to survive in high salt environments, where mesophilic organisms would perish. One of the biggest challenges faced by halophilic proteins is the ability to maintain both the structure and function at molar concentrations of salt. A distinct adaptation of halophilic proteins, compared to mesophilic homologues, is the abundance of aspartic acid on the protein surface. Mutagenesis and crystallographic studies of halophilic proteins suggest an important role for solvent interactions with the surface aspartic acid residues. This interaction, between the regions of the acidic protein surface and the solvent, is thought to maintain a hydration layer around the protein at molar salt concentrations thereby allowing halophilic proteins to retain their functional state. Here we present neutron diffraction data of the monomeric zwitterionic form of aspartic acid solutions at physiological pH in 0.25 M and 2.5 M concentration of potassium chloride, to mimic mesophilic and halophilic-like environmental conditions. We have used isotopic substitution in combination with empirical potential structure refinement to extract atomic-scale information from the data. Our study provides structural insights that support the hypothesis that carboxyl groups on acidic residues bind water more tightly under high salt conditions, in support of the residue-ion interaction model of halophilic protein stabilisation. Furthermore our data show that in the presence of high salt the self-association between the zwitterionic form of aspartic acid molecules is reduced, suggesting a possible mechanism through which protein aggregation is prevented.
Collapse
Affiliation(s)
- Samuel Lenton
- School of Physics and Astronomy, University of Leeds, Leeds, UK.
| | | | | | | | | |
Collapse
|
48
|
Dong K, Zhang S, Wang J. Understanding the hydrogen bonds in ionic liquids and their roles in properties and reactions. Chem Commun (Camb) 2016; 52:6744-64. [PMID: 27042709 DOI: 10.1039/c5cc10120d] [Citation(s) in RCA: 162] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Ionic liquids (ILs) have many potential applications in the chemical industry. In order to understand ILs, their molecular details have been extensively investigated. Intuitively, electrostatic forces are solely important in ILs. However, experiments and calculations have provided strong evidence for the existence of H-bonds in ILs and their roles in the properties and applications of ILs. As a structure-directing force, H-bonds are responsible for ionic pairing, stacking and self-assembling. Their geometric structure, interaction energy and electronic configuration in the ion-pairs of imidazolium-based ILs and protic ionic liquids (PILs) show a great number of differences compared to conventional H-bonds. In particular, their cooperation with electrostatic, dispersion and π interactions embodies the physical nature of H-bonds in ILs, which anomalously influences their properties, leading to a decrease in their melting points and viscosities and thus fluidizing them. Using ILs as catalysts and solvents, many reactions can be activated by the presence of H-bonds, which reduce the reaction barriers and stabilize the transition states. In the dissolution of lignocellulosic biomass by ILs, H-bonds exhibit a most important role in disrupting the H-bonding network of cellulose and controlling microscopic ordering into domains. In this article, a critical review is presented regarding the structural features of H-bonds in ILs and PILs, the correlation between H-bonds and the properties of ILs, and the roles of H-bonds in typical reactions.
Collapse
Affiliation(s)
- Kun Dong
- State Key Laboratory of Multiphase Complex System, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, P. R. China.
| | | | | |
Collapse
|
49
|
Steinke N, Gillams RJ, Pardo LC, Lorenz CD, McLain SE. Atomic scale insights into urea–peptide interactions in solution. Phys Chem Chem Phys 2016; 18:3862-70. [DOI: 10.1039/c5cp06646h] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Investigations on the β-turn forming peptide, GPG, suggest that urea denatures proteins by replacing water molecules and subsequently weakening the peptide bonds as a possible mechanism of protein denaturation by urea.
Collapse
Affiliation(s)
- Nicola Steinke
- Department of Biochemistry
- University of Oxford
- Oxford OX1 3QU
- UK
| | | | - Luis Carlos Pardo
- Departament de Física i Enginyeria Nuclear
- Escola Tècnica Superior d'Enginyeria Industrial de Barcelona (ETSEIB)
- Universitat Politècnica de Catalunya
- 08028 Barcelona
- Catalonia, Spain
| | | | | |
Collapse
|
50
|
Sprenger K, Pfaendtner J. Using Molecular Simulation to Study Biocatalysis in Ionic Liquids. Methods Enzymol 2016; 577:419-41. [DOI: 10.1016/bs.mie.2016.05.020] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
|