combine the properties of ILs such as high ion conductivity, electrochemical
stability, and negligable vapor pressure with the prominent benefits of polymers
regarding their facile processing and easy design of multifunctional materials.
Today, films, coatings, dispersions, gels, solid electrolytes, and composite materials
are made from PILs. The envisioned PIL applications range from advanced
electrochemical devices such as batteries, fuel cells, and sensors to membranes
for highly diversified applications in separation technology. Going well beyond
the scope of traditional polyelectrolytes and polymer ionomers, this remarkable
progress made in PIL research and development is opening up new horizons in
polymer electrolyte science and engineering.
Inspite of these obvious PIL advantages, there exist several shortcomings,
especially with repect to PIL appliactions in electrochemical devices. Above all, it
is well recognized that the ion conductivities of high molecular weight PILs are much
lower than those of the low molecular weight ILs. In fact, with increasing molecular
weight, the decrease in ion mobility is frequently paralleled by increasing glass
transition temperature [17]. Although the variation of linear PIL architectures has
only limited potential to overcome this problem, controlled nanostructure formation
offers unique unexplored opportunities. On the one hand, novel dendritic and
hyperbranched nanometer-scaled PILs are being tailored to exhibit micelle-like
structure and properties. On the other hand, nanophase separation is being exploited
to produce novel polymer electrolyte nanomaterials from tailored amphiphilic PILs,
PIL blends, PIL interpenetrating networks, and PIL nanoparticle dispersions. In the
future, better understanding and control of PIL nanostructure formation will be the
key issue for achieving success in commercial PIL applications.
References
1. Welton T (1999) Room-temperature ionic liquids. Solvents for synthesis and catalysis. Chem
Rev 99:2071–2084
2. Hallett JP, Welton T (2011) Room-temperature ionic liquids: solvents for synthesis and
catalysis. 2. Chem Rev 111:3508–3576
3. Dupont J, de Souza RF, Suarez PAZ (2002) Ionic liquid (molten salt) phase organometallic
catalysis. Chem Rev 102:3667–3692
4. Pa ˆrvulescu VI, Hardacre C (2007) Catalysis in ionic liquids. Chem Rev 107:2615–2665
5. Wasserscheid P, Keim W (2000) Ionic liquids – new “solutions” for transition metal catalysis.
Angew Chem Int Ed 39:3772–3789
6. Olivier-Bourbigou H, Magna L, Morvan D (2010) Ionic liquids and catalysis: recent progress
from knowledge to applications. Appl Catal A 373:1–56
7. Wasserscheid P, Welton T (2007) Ionic liquids in synthesis, vol 2. Wiley-VCH, Weinheim
8. Wasserscheid P, Welton T (2003) Ionic liquids in synthesis. Wiley-VCH, Weinheim
9. Brazel CS, Rogers RD (2005) Ionic liquids in polymer systems solvents additives and novel
applications. American Chemical Society, Washington, DC
10. Canongia Lopes JNA, Pa ´dua AAH (2006) Nanostructural organization in ionic liquids. J Phys
Chem B 110:3330–3335
Nanostructured Polymeric Ionic Liquids
441
stability, and negligable vapor pressure with the prominent benefits of polymers
regarding their facile processing and easy design of multifunctional materials.
Today, films, coatings, dispersions, gels, solid electrolytes, and composite materials
are made from PILs. The envisioned PIL applications range from advanced
electrochemical devices such as batteries, fuel cells, and sensors to membranes
for highly diversified applications in separation technology. Going well beyond
the scope of traditional polyelectrolytes and polymer ionomers, this remarkable
progress made in PIL research and development is opening up new horizons in
polymer electrolyte science and engineering.
Inspite of these obvious PIL advantages, there exist several shortcomings,
especially with repect to PIL appliactions in electrochemical devices. Above all, it
is well recognized that the ion conductivities of high molecular weight PILs are much
lower than those of the low molecular weight ILs. In fact, with increasing molecular
weight, the decrease in ion mobility is frequently paralleled by increasing glass
transition temperature [17]. Although the variation of linear PIL architectures has
only limited potential to overcome this problem, controlled nanostructure formation
offers unique unexplored opportunities. On the one hand, novel dendritic and
hyperbranched nanometer-scaled PILs are being tailored to exhibit micelle-like
structure and properties. On the other hand, nanophase separation is being exploited
to produce novel polymer electrolyte nanomaterials from tailored amphiphilic PILs,
PIL blends, PIL interpenetrating networks, and PIL nanoparticle dispersions. In the
future, better understanding and control of PIL nanostructure formation will be the
key issue for achieving success in commercial PIL applications.
References
1. Welton T (1999) Room-temperature ionic liquids. Solvents for synthesis and catalysis. Chem
Rev 99:2071–2084
2. Hallett JP, Welton T (2011) Room-temperature ionic liquids: solvents for synthesis and
catalysis. 2. Chem Rev 111:3508–3576
3. Dupont J, de Souza RF, Suarez PAZ (2002) Ionic liquid (molten salt) phase organometallic
catalysis. Chem Rev 102:3667–3692
4. Pa ˆrvulescu VI, Hardacre C (2007) Catalysis in ionic liquids. Chem Rev 107:2615–2665
5. Wasserscheid P, Keim W (2000) Ionic liquids – new “solutions” for transition metal catalysis.
Angew Chem Int Ed 39:3772–3789
6. Olivier-Bourbigou H, Magna L, Morvan D (2010) Ionic liquids and catalysis: recent progress
from knowledge to applications. Appl Catal A 373:1–56
7. Wasserscheid P, Welton T (2007) Ionic liquids in synthesis, vol 2. Wiley-VCH, Weinheim
8. Wasserscheid P, Welton T (2003) Ionic liquids in synthesis. Wiley-VCH, Weinheim
9. Brazel CS, Rogers RD (2005) Ionic liquids in polymer systems solvents additives and novel
applications. American Chemical Society, Washington, DC
10. Canongia Lopes JNA, Pa ´dua AAH (2006) Nanostructural organization in ionic liquids. J Phys
Chem B 110:3330–3335
Nanostructured Polymeric Ionic Liquids
441