Cellulose in Ionic Liquids and Alkaline Solutions: Advances in the Mechanisms of Biopolymer Dissolution and Regeneration

This review is focused on assessment of solvents for cellulose dissolution and the mechanism of regeneration of the dissolved biopolymer. The solvents of interest are imidazole-based ionic liquids, quaternary ammonium electrolytes, salts of super-bases, and their binary mixtures with molecular solvents. We briefly discuss the mechanism of cellulose dissolution and address the strategies for assessing solvent efficiency, as inferred from its physico-chemical properties. In addition to the favorable effect of lower cellulose solution rheology, microscopic solvent/solution properties, including empirical polarity, Lewis acidity, Lewis basicity, and dipolarity/polarizability are determinants of cellulose dissolution. We discuss how these microscopic properties are calculated from the UV-Vis spectra of solvatochromic probes, and their use to explain the observed solvent efficiency order. We dwell briefly on use of other techniques, in particular NMR and theoretical calculations for the same purpose. Once dissolved, cellulose is either regenerated in different physical shapes, or derivatized under homogeneous conditions. We discuss the mechanism of, and the steps involved in cellulose regeneration, via formation of mini-sheets, association into “mini-crystals”, and convergence into larger crystalline and amorphous regions. We discuss the use of different techniques, including FTIR, X-ray diffraction, and theoretical calculations to probe the forces involved in cellulose regeneration.

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Effect of the Structures of Ionic Liquids on Their Physical-Chemical Properties and the Phase Behavior of Mixtures Involving Ionic Liquids

Chemical Reviews ◽

10.1021/cr0502044 ◽

2006 ◽

Vol 0 (0) ◽

pp. 0-0 ◽

Cited By ~ 4

Author(s):

Y.-F. Hu ◽

C.-M. Xu

Keyword(s):

Ionic Liquids ◽

Phase Behavior ◽

Chemical Properties ◽

Physical Chemical

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Synthesis, Characterization and Applications of Dicationic Ionic Liquids in Organic Synthesis

Mini-Reviews in Organic Chemistry ◽

10.2174/1570193x16666190508091231 ◽

2020 ◽

Vol 17 (4) ◽

pp. 450-464

Author(s):

Mohammad Javaherian ◽

Seyyed Jafar Saghanezhad

Keyword(s):

Ionic Liquids ◽

Organic Synthesis ◽

Chemical Properties ◽

Physical And Chemical Properties ◽

Dicationic Ionic Liquids ◽

Physical And Chemical ◽

Reaction Media ◽

And Chemical Properties

Dicationic ionic liquids are an emerging group of Ionic Liquids (ILs) that are currently receiving much attention as green reaction media and catalysts. Because of a great number of possible combinations of cations and anions, the physical and chemical properties of dicationic ionic liquids are more tunable and broader than monocationic ILs. Therefore, their unique properties have made them the target of many applied and fundamental researches. Actually, dicationic ionic liquids are more effective and rather fascinating than traditional monocationic ILs. So, due to greater versatility and diversity, their applications in organic synthesis have been extensively grown. In this review, we have focused on the synthesis, characterization and applications of dicationic ionic liquids, especially, in organic synthesis.

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Controlling surface chemistry and mechanical properties of metal ionogels through Lewis acidity and basicity

Journal of Materials Chemistry A ◽

10.1039/d0ta11821d ◽

2021 ◽

Vol 9 (8) ◽

pp. 4679-4686

Author(s):

Coby J. Clarke ◽

Richard P. Matthews ◽

Alex P. S. Brogan ◽

Jason P. Hallett

Keyword(s):

Mechanical Properties ◽

Ionic Liquids ◽

Ethylene Glycol ◽

Surface Chemistry ◽

Lewis Acidity ◽

Metal Species ◽

Poly Ethylene Glycol ◽

Acidity And Basicity ◽

Poly Ethylene

Gels prepared from metal containing ionic liquids with cross-linked poly(ethylene glycol) have surface compositions and mechanical properties that can be controlled by Lewis basicity and acidity of the metal species.

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15N NMR studies provide insights into physico-chemical properties of room-temperature ionic liquids

Physical Chemistry Chemical Physics ◽

10.1039/d1cp01492g ◽

2021 ◽

Author(s):

Christoph Wiedemann ◽

David Fushman ◽

Frank Bordusa

Keyword(s):

Ionic Liquids ◽

Room Temperature ◽

Chemical Properties ◽

Room Temperature Ionic Liquids ◽

15N Nmr ◽

Nmr Studies ◽

Physico Chemical ◽

Alternative Solvents

Ionic liquids (ILs) have gained a lot of attention as alternative solvents in many fields of science in the last two decades. It is known that the type of anion...

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Synthesis, antibiotic structure–activity relationships, and cellulose dissolution studies of new room-temperature ionic liquids derived from lignin

Biotechnology for Biofuels ◽

10.1186/s13068-021-01898-x ◽

2021 ◽

Vol 14 (1) ◽

Cited By ~ 1

Author(s):

Shihong Liu ◽

Michael Gonzalez ◽

Celine Kong ◽

Scott Weir ◽

Aaron M. Socha

Keyword(s):

Antibacterial Activity ◽

Ionic Liquids ◽

Room Temperature ◽

Oxidation Products ◽

Cellulose Dissolution ◽

Melting Points ◽

E Coli ◽

Alkyl Chains ◽

Renewable Feedstocks ◽

Commodity Chemicals

Abstract Background Ionic liquids (ILs) are promising pretreatment solvents for lignocellulosic biomass, but are largely prepared from petroleum precursors. Benzaldehydes from depolymerized lignin, such as vanillin, syringaldehyde, and 4-methoxy benzaldehyde, represent renewable feedstocks for the synthesis of ionic liquids. We herein report syntheses of novel lignin-derived ionic liquids, with extended N-alkyl chains, and examine their melting points, cellulose dissolution capacities, and toxicity profiles against Daphnia magna and E. coli strain 1A1. The latter organism has been engineered to produce isoprenol, a drop-in biofuel and precursor for commodity chemicals. Results The new N,N-diethyl and N,N-dipropyl methyl benzylammonium ILs were liquids at room temperature, showing 75–100 °C decreased melting points as compared to their N,N,N-trimethyl benzylammonium analog. Extension of N-alkyl chains also increased antibacterial activity threefold, while ionic liquids prepared from vanillin showed 2- to 4-fold lower toxicity as compared to those prepared from syringaldehyde and 4-methoxybenzaldehyde. The trend of antibacterial activity for anions of lignin-derived ILs was found to be methanesulfonate < acetate < hydroxide. Microcrystalline cellulose dissolution, from 2 to 4 wt% after 20 min at 100 °C, was observed in all new ILs using light microscopy and IR spectroscopy. Conclusions Ionic liquids prepared from H-, S- and G-lignin oxidation products provided differential cytotoxic activity against E. coli and D. magna, suggesting these compounds could be tailored for application specificity within a biorefinery.

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Silver Nanoparticles Supported on Ordered Mesoporous Carbon for Formaldehyde Electrooxidation

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.110-116.508 ◽

2011 ◽

Vol 110-116 ◽

pp. 508-513

Author(s):

Ling Bin Kong ◽

Ru Tao Wang ◽

Xiao Wei Wang ◽

Zhen Sheng Yang ◽

Yong Chun Luo ◽

...

Keyword(s):

Fuel Cells ◽

Mesoporous Carbon ◽

Chemical Reduction ◽

Chemical Properties ◽

Ordered Mesoporous Carbon ◽

Alkaline Solutions ◽

Cyclic Voltammograms ◽

Peak Current Density ◽

Ordered Mesoporous ◽

Physical And Chemical

Metal nanocatalysts, as the anodic materials, have become increasingly important in fuel cells due to their unique physical and chemical properties. Here we report the ordered mesoporous carbon (CMK-3) supported silver nanocatalysts have been prepared through the wet chemical reduction by using the reduction of formaldehyde. The electrochemical properties of the Ag/CMK-3 nanocatalysts for formaldehyde oxidation are studied by cyclic voltammograms (CV) and chronoamperometric curves (i-t) in alkaline aqueous solutions. The results show that the peak current density (from CV) of the Ag/CMK-3 electrode is 112 mA cm-2, above 2 times higher than that of Ag/XC-72 at the same Ag loading (14.15 μg cm-2). Furthermore, the i-t curves demonstrate that the Ag/CMK-3 nanocatalysts are efficient and stable electrocatalysts for anodic oxidation of formaldehyde in alkaline solutions. Our results indicate that the application potential of Ag/CMK-3 nanocatalysts with the improved electrocatalytic activity has far reaching effects on fuel cells and sensors.

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Ionic Liquids in Analytical Chemistry: Applications and Recent Trends

Current Analytical Chemistry ◽

10.2174/1573411017666210331113712 ◽

2021 ◽

Vol 17 ◽

Author(s):

Giuseppe Maria Merone ◽

Angela Tartaglia ◽

Enrica Rosato ◽

Cristian D’Ovidio ◽

Abuzar Kabir ◽

...

Keyword(s):

Analytical Chemistry ◽

Ionic Liquids ◽

Stationary Phases ◽

Extraction Procedure ◽

Chemical Properties ◽

Electrochemical Analysis ◽

Physico Chemical ◽

Recent Trends ◽

Number Of Publications ◽

Physical And Chemical

Background: Ionic liquids (ILs) are a unique class of compounds consisting exclusively of cations and anions that possess distinctive properties such as low volatility, high thermal stability, miscibility with water and organic solvents, electrolytic conductivity and non-flammability. Ionic liquids have been defined as "design solvents", because it is possible to modify their physical and chemical properties by appropriately choosing cations and anions, in order to meet the specific characteristics based on their potential application. Introduction: Due of their tunable nature and properties, ILs are considered as the perfect candidates for numerous applications in analytical chemistry including sample preparation, stationary phases in liquid or gas chromatography, additives in capillary electrophoresis, or in mass spectrometry for spectral and electrochemical analysis. In the last years, the number of publications regarding ILs has rapidly increased, highlighting the broad applications of these compounds in various fields of analytical chemistry. Results: This review first described the main physico-chemical characteristics of ionic liquids, and subsequently reported the various applications in different subdisciplines of analytical chemistry, including the extraction procedure and separation techniques. Furthermore, in each paragraph the most recent applications of ionic liquids in the food, environmental, biological, etc. fields have been described. Conclusion: Overall, the topic discussed highlights the key role of ionic liquids in analytical chemistry, giving hints for their future applications in chemistry but also in biology and medicine.

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Mixed Chlorometallate Ionic Liquids as C4 Alkylation Catalysts: A Quantitative Study of Acceptor Properties

Catalysts ◽

10.3390/catal8110498 ◽

2018 ◽

Vol 8 (11) ◽

pp. 498

Author(s):

Xiaoying Pang ◽

Ying Liu ◽

Juanfang Wang

Keyword(s):

Ionic Liquids ◽

Lewis Acidity ◽

Alkylation Reaction ◽

Triethylamine Hydrochloride ◽

Metal Chlorides ◽

Molar Ratios ◽

Anionic Species ◽

Triethylphosphine Oxide ◽

The Relationship ◽

Acceptor Numbers

The acceptor properties of mixed chlorometallate ionic liquids for isobutane-butene alkylation (C4 alkylation) reaction were studied. These ionic liquids were prepared by mixing metal chlorides with either triethylamine hydrochloride or 1-butyl-3-methylimidazolium chloride in various molar ratios. Using triethylphosphine oxide as a probe, Gutmann Acceptor Numbers (AN) of the catalysts were determined, and the Lewis acidity of mixed chlorometallate ionic liquids was quantitatively measured. Additionally, AN value was developed to determine the relationship between Lewis acidity and catalytic selectivity. The favorite AN value for the C4 alkylation reaction should be around 93.0. The [(C2H5)3NH]Cl–AlCl3−CuCl appears to be more Lewis acidity than that of [(C2H5)3NH]Cl–AlCl3. The correlation of the acceptor numbers to speciation of the mixed chlorometallate ionic liquids has also been investigated. [AlCl4]−, [Al2Cl7]−, and [MAlCl5]− (M = Cu, Ag) are the main anionic species of the mixed chlorometallate ILs. While the presence of [(C2H5)3N·M]+ cation always decreases the acidity of the [(C2H5)3NH]Cl−AlCl3−MCl ionic liquids.

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