Thermosensitive Self-Assembly of Diblock Copolymers with Lower Critical Micellization Temperatures in an Ionic Liquid

Tamura, Saki; Ueki, Takeshi; Ueno, Kazuhide; Watanabe, Masayoshi

doi:10.1021/ma900922d

Cited by 49 publications

(51 citation statements)

References 51 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…P(BnMA-b-MMA), where the MMA segment is solvatophilic, exhibits this type of self-assembly in the hydrophobic IL [C 2 mim][NTf 2 ]. 149 In addition, doubly thermosensitive micellar aggregation in an IL (or IL mixtures) was also demonstrated using block copolymers consisting of segments that exhibit LCST and UCST. These polymers include P(BnMA-b-NIPAm) and P(BnMA-b-(NIPAm-r-AAm)).…”

Section: Self-assembly Of Block Copolymers In Ionic Liquidsmentioning

confidence: 99%

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

Ueki

Watanabe

2011

Bulletin of the Chemical Society of Japan

Self Cite

157

144

View full text Add to dashboard Cite

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

Section: Self-assembly Of Block Copolymers In Ionic Liquidsmentioning

confidence: 99%

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

Ueki

Watanabe

2011

Bulletin of the Chemical Society of Japan

Self Cite

157

144

View full text Add to dashboard Cite

show abstract

“…An increase in the miscibility of imidazolium ILs with longer alkyl chains was also observed in other binary mixture systems, alcohol/IL systems and polymethacrylate/IL systems. [19][20][21][28][29][30][31][32][33][34][35][36] LCST phase separation of binary mixtures is governed by the magnitude of negative enthalpy and negative entropy changes of mixing (vide infra). A large decrease in the latter results in lower phase separation temperatures.…”

Section: Influence Of Cation Structures On Phase Separation Temperaturesmentioning

confidence: 99%

“…[16][17][18] Brennecke and co-workers have examined the phase behavior of IL/alcohol mixtures thoroughly and revealed their upper critical solution temperature behavior. [19][20][21] Other binary systems such as IL/haloalkane, 22,23 IL/CO 2 , 24,25 IL/ IL 26,27 and IL/synthetic polymer [28][29][30][31][32][33][34][35][36] systems have also exhibited unique phase behavior. This unique phase behavior has not only given us a better understanding of ILs but has also highlighted their potential for use in several applications, for example, in separation and purification processes and stimuli-responsive polymers.…”

Section: Introductionmentioning

confidence: 99%

Structural effects of polyethers and ionic liquids in their binary mixtures on lower critical solution temperature liquid-liquid phase separation

Kodama

Tsuda

Niitsuma

et al. 2011

Polym J

Self Cite

103

View full text Add to dashboard Cite

The solubility and phase behavior of five polyethers (poly(ethylene oxide), poly(glycidyl methyl ether), poly(ethyl glycidyl ether), poly(ethoxyethyl glycidyl ether) and poly(propylene oxide)) in 14 different room-temperature ionic liquids (ILs) were studied by changing the structures of polyethers and the cations and anions in the ILs. Certain combinations of a polyether and an IL binary mixture exhibited lower critical solution temperature (LCST) phase behavior. For ILs containing the same anions, the polyethers were highly soluble in imidazolium-or pyridinium-based ILs, whereas they were insoluble in ammonium-or phosphonium-based ILs. An increase in length of the alkyl chain in the imidazolium cation and an increase in polarity of the polyethers resulted in a higher LCST phase separation temperature, whereas substitution of the hydrogen atoms on the imidazolium ring by methyl groups resulted in a lower LCST phase separation temperature. The hydrogen bonding interaction between the oxygen atoms in the polyethers and the aromatic hydrogen atoms on the cations in the ILs had an important role in the LCST phase behavior of the mixtures. Miscibility of the mixtures was also affected by the Lewis basicity of the anions in the ILs.

show abstract

“…11). These findings open up the possibility of stimuli-responsive molecular assemblies, [135][136][137] volume-phase transitions of ion gels, 128 and temperature-induced sol/gel transitions [138][139][140] in ILs. Recently, stimuli-responsiveness has expanded to include photo-stimuli using photochromic compounds, [141][142][143][144][145][146] and photo-healing materials 147,148 have been proposed.…”

Section: Phase Behavior Of Polymers In Ils and Materializationmentioning

confidence: 81%

Design and Materialization of Ionic Liquids Based on an Understanding of Their Fundamental Properties

Watanabe

2016

Electrochemistry

Self Cite

View full text Add to dashboard Cite

Ionic liquids (ILs) are defined as salts that have melting points lower than 100°C. Most are organic salts, and these may be designed and tailored to have suitable properties. ILs are recognized as a third group of solvents (and electrolytes), after water and organic solvents. They are characterized by their unique properties such as nonvolatilities, high thermal stabilities, and high ionic conductivities. In this article, our work on the design and preparation of ILs is briefly reviewed. The concept of ionicity is proposed as a metric to characterize the basic nature (dissociativity) of ILs, which is affected by the Lewis acidity/basicity of cations/anions (i.e., coulombic interactions), the directionality of interactions between cations and anions, and van der Waals interactions between ions. The ionicity of ILs is dominated by a subtle balance between coulombic and van der Waals interactions, which clearly discriminates ILs from conventional high-temperature inorganic molten salts. Here, the design of protic ILs for fuel cell electrolytes, electron-transporting ILs for dye-sensitized solar cell electrolytes, and Li + -conducting solvate ILs for lithium battery electrolytes are discussed based on an understanding of the fundamental properties of ILs. Furthermore, the combination of ILs with polymers and colloidal particles affords intriguing quasi-solid materials (ion gels), and the ion transport in these gels is decoupled from the mechanical relaxation time of these materials, yielding new solid electrolytes. The possibility of temperature and photo-sensitive solubility dependence of polymers in ILs allows the creation of stimuli-responsive materials. Finally, protic ILs/protic salts are demonstrated to be good precursors for N-doped carbon materials.

show abstract

Thermosensitive Self-Assembly of Diblock Copolymers with Lower Critical Micellization Temperatures in an Ionic Liquid

Cited by 49 publications

References 51 publications

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

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

Structural effects of polyethers and ionic liquids in their binary mixtures on lower critical solution temperature liquid-liquid phase separation

Design and Materialization of Ionic Liquids Based on an Understanding of Their Fundamental Properties

Contact Info

Product

Resources

About