Liquid mixtures of ionic liquids and polymers as solvent systems

In this paper, we review recent advances in the use of polymers in ionic liquids (ILs) from the view point of the "dawn of neoteric solvents and innovative materials." The first part of this paper presents a brief review of the solubility parameters of ILs, which are expected to serve as a qualitative guide for predicting polymer solubility in ILs; however, this concept cannot be used to rationalize a number of cases in which strong Coulombic interactions dominate the solubility parameters of the ILs. Thus, solubility of 24 different common synthetic polymers is experimentally demonstrated under dilute conditions (3 wt %) in four different common ILs. It is found that the Lewis basicities of the counter anions in the ILs play an important role in determining the solubility of the polymers. ILs can also be used as good solvents for low-solubility biopolymers and as good dispersion media of carbon nanotubes, which contributes to the fields of biorefinery processes and advanced materials. Certain combinations of polymers in ILs undergo phase separations as the temperature of the solutions is varied. The solubility of a nonionic polymer in water generally decreases with increasing temperature, and certain combinations exhibit lower critical solution temperature (LCST) phase separation, whereas the solubility of a polymer in an organic solvent generally increases with increasing temperature and in some cases upper critical solution temperature (UCST) phase separation is observed. Interestingly, both LCST and UCST phase separations are observed for certain polymers in ILs. After presenting possible explanations of the solubility of polymers in ILs, recent developments in the field of thermosensitive polymers in ILs are discussed from the perspective of materials science, where such phase separations are exploited to trigger abrupt changes in polymer properties. The final part of this review describes the thermosensitive self-assembly of block copolymers in ILs. Similar to conventional molecular solvents, block copolymers in ILs exhibit variable self-assemblies in solution and in the bulk.

show abstract

“…116 Liquidliquid phase separation of polyethers and ILs also represents a promising platform for achieving novel extraction and reaction media.…”

Section: Ionic Liquids As Solvents For Low-solubility Biopolymers Andmentioning

confidence: 99%

Polymers in Ionic Liquids: Dawn of Neoteric Solvents and Innovative Materials

Ueki

Watanabe

2011

Bulletin of the Chemical Society of Japan

155

144

View full text Add to dashboard Cite

show abstract

“…The mixtures of polymers and ILs can exhibit outstanding characteristics such as good solvation ability, very low volatility, and tunable physical as well as thermal properties [1]. Use of these systems is not limited to their applications as solvent.…”

Section: Introductionmentioning

confidence: 99%

Spectroscopic and viscometric studies on the interaction of ionic liquid, 1-butyl-3-methylimidazolium bromide with polyvinyl pyrrolidone

Mehrdad

Niknam

2015

Fluid Phase Equilibria

View full text Add to dashboard Cite

“…Typically polydisperse hyperbranched polymers are globular, three-dimensional macromolecules with a large number of functional end groups increasing exponentially with a generation of the polymer. The HPs became the focus of research in academic society as new potential solvents of applications in the field of chemical engineering [1][2][3][4][5][6]. An interesting aspect of HPs is that the physical and chemical properties are dependent on the mass fraction and substituent end groups.…”

Section: Introductionmentioning

confidence: 99%

“…HPs have practically negligible vapour pressure and are used as novel solvents with an enhanced degree of tunability. Moreover, these characteristics and other such as toxicity or biodegradability can be tuned by judicious of the combination of polar-end groups constitutive of the HP [6]. The possible application was widely discussed in the review given by Seiler and co-workers [5].…”

Section: Introductionmentioning

confidence: 99%