Ionic liquids: current developments, potential and drawbacks for industrial applications (original) (raw)
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Ionic Liquids as Environmental Benign Solvents for Cellulose Chemistry: A Review
Solvents, Ionic Liquids and Solvent Effects
The application of cellulose and its derivatives is restricted because of their limited solubility in water and many organic solvents. Recently, several attempts are being made to dissolve them in inorganic and organic solvents. The solubility of these polymeric materials mainly depends upon their molecular weight, pH, and source of origin. Nowadays, there has been a new breakthrough of applying ionic liquids (ILs; designer solvents) in the field of cellulose solvent chemistry. Association of ionic liquids with several salient features such as high thermal, chemical and low vapor pressure, and so on makes them ideal environmentally green solvents to be used for cellulose. The present chapter deals with a collection of some major works in which ionic liquids have been used as solvents for cellulose dissolution. The articles also describe the works illustrating the use of ionic liquids as cosolvents (organic aprotic solvents) for the better increase of the solvent activity (solubility).
Dissolution of cellulose in ionic liquid: A review
AIP Conference Proceedings
Dissolution of cellulose with ionic liquids (IL) and deep eutectic solvent (DES) lets the comprehensive dissolution of cellulose. Basically, cellulose can be dissolved, in some hydrophilic ionic liquids, such as 1-butyl-3-methylimidazolium chloride (BMIMCl) and 1-allyl-3-methylimidazolium chloride (AMIMCl). Chloride based ionic liquids are suitable solvents for cellulose dissolution. Although the ILs is very useful in fine chemical industry, its application in the pharmaceutical and food industry have been very limited due to issues with toxicity, purity, and high cost. Seeing to these limitations, new green alternative solvent which is DES was used. This green solvents, may be definitely treated as the next-generation reagents for more sustainable industrial development. Thus, this review aims to discuss the dissolution of cellulose either with ionic liquids or DES and its application.
There is an increasing willingness to develop new cellulose-based materials due to the fact that cellulose is the earth´s most abundant biorenewable macromolecular resource. The efficient dissolution of cellulose is a longstanding goal in cellulose research and is still of great importance. This article gives a short survey of the relevant literature with respect to historical developments and potential industrial uses of ionic liquids and then proceeds to the latest results in cellulose/ionic liquid chemistry. Cellulose can be dissolved in several ionic liquids and can easily be regenerated by contacting with water. Dissolution and reconstitution experiments, fiber characteristics and molecular mass distribution data are described. The single crystal X-ray structure determination of the cellulose solvent 1-allyl-3methylimidazolium chloride is presented. 162 references are given.
STRUCTURAL PROPERTIES OF CELLULOSE REGENERATED FROM ITS IONIC LIQUID SOLUTIONS
In this paper, structural features of cellulose regenerated from its corresponding solutions in 1-ethyl-3-methylimidazolium acetate, 1-allyl-3-methylimidazolium chloride and 1-buthyl-3-methylimidazolium chloride ionic liquids have been assessed by FTIR spectroscopy, contact angle and methylene blue sorption studies.
2010
Cellulose is one of the most abundant biological and renewable materials in the world. The application of cellulose is widely distributed among various industries such as fiber, paper, pharmaceutical, membrane, polymer and paint. However, the utilization of cellulose or cellulosic materials has not been developed entirely because of its poor solubility in common organic solvents. Ionic liquids (ILs) are relatively new family of solvents for dissolution of cellulose. They are organic salts contain only cations and anions with low melting temperature, which make them suitable for the solubilization of cellulose. Moreover, ILs are non-volatile, non-toxic, non-flammable and thermally and chemically stable. Cellulose dissolved in ILs can be regenerated with anti-solvents as water, ethanol and acetone. In this study, both the dissolution and regeneration of hardwood and softwood dissolving pulps with and from two ILs ([C mim + ]CH 3 COOand [C4mim + ]Cl-) were investigated. Furthermore, the impact of treating cellulose with ILs was also evaluated by using different analytical techniques, such as size exclusion chromatography (SEC), thermal gravimetric analysis (TGA) and scanning electron microscopy (SEM).
Distillable Acid-Base Conjugate Ionic Liquids for Cellulose Dissolution and Processing
Angewandte Chemie International Edition, 2011
Future biorefinery concepts are seriously entertaining the use of ionic liquids (ILs) as a platform media for the processing of woody material as a second-generation biomass feedstock. The main motivation is the demonstrated efficiency of some molten salts in the dissolution of cellulose, a major structural and solvolytically resistant component of lignocellulosic materials.
Chemical Engineering Journal, 2009
Recent studies on the application of room temperature ionic liquids (RTILs) in cellulose chemistry have made great progresses. This has been providing a new and versatile platform for the wide utilization of cellulose resources and creation of novel functional materials. In this paper, the research progress in the field of dissolution, regeneration and derivatization of cellulose with RTILs are reviewed. And the perspective of RTIL application in cellulose industry is also discussed.
Mixtures of ionic liquids as more efficient media for cellulose dissolution
Carbohydrate Polymers, 2017
Highlights The ability of ionic liquids eutectic mixture to dissolve cellulose was studied. Addition of DMSO to the ionic liquid mixture improves the cellulose dissolution. Up to 43 g of cellulose per 100 g of used solvent mixture could be dissolved. Anisotropy was observed in the solutions with highest cellulose concentration. The dissolved cellulose could be easily reconstituted from the solutions. The IR spectroscopy can be used to assess the purity of the regenerated cellulose.