Electrochemical Aspects of Ionic Liquids (Ohno/Electrochemical Aspects of Ionic Liquids) || Ionic Liquid Gels

✍ Scribed by Ohno, Hiroyuki

• Publisher: John Wiley & Sons, Inc.
• Year: 2005
• Tongue: English
• Weight: 97 KB
• Edition: 1
• Category: Article
• ISBN: 0471648515
• DOI: 10.1002/0471762512.ch26

✦ Synopsis

Very recently ionic liquids have received much attention for materials in greensustainable chemistry . Ionic liquids composed of ions only have good properties such as extremely low volatility, high thermal stability, wide temperature range for liquid phase, nonflammability, high chemical stability, high ionic conductivity, and wide electrochemical window. Here the preparation of ionic liquid gels and the properties of formed gels are described.

26.1 GELATION OF IONIC LIQUIDS BY LOW MOLECULAR WEIGHT GELATORS

Low molecular weight compounds capable of hardening organic liquids, which are called ''gelators,'' are of special interest for not only academic objects but also potential applications . Gelators have unique characteristics of both good solubility upon heating and inducement of smooth gelation of organic fluids at low concentration. For example, when the hot solution containing gelators is cooled to room temperature, the gel is easily formed in the course of cooling process. The formed gels always exhibit thermally reversible sol-to-gel phase transition. Because the driving forces of physical gelation by gelator are cooperating noncovalent interactions of gelator molecules, such as hydrogen bonding, hydrophobic interaction, p-p interaction, and electrostatic interaction.

With low melting point in mind, nine ionic liquids shown in Figure .1 were tested for gelation. The six kinds of imidazolium salts, the two kinds of ammonium Electrochemical Aspects of Ionic Liquids Edited by Hiroyuki Ohno