Beyond solvents and electrolytes: Ionic liquids-based advanced functional materials

Abstract

Instead of being seen as alternative solvents and electrolytes for organic reactions, catalysis, separation, electrochemistry, and so on, ionic liquids (ILs) consisting of discrete cations and anions have recently emerged as versatile building blocks for advanced functional materials. A number of functional ILs and IL-containing composite materials have been realized by either chemical modification (covalent functionalization or ion-exchange metathesis) or physical integration of ILs and traditional materials. The unique structure and behavior of ILs as a platform not only provides additional opportunities to adjust the physicochemical properties of these ionic materials for task-specific applications, but also offers other attractive features such as intrinsic ionic conductivity and high thermal, chemical, and electrochemical stability. These soft materials combine the favorable features of ILs and the original chemistries of the functional groups or materials; some even possess unexpected functions resulting from synergetic interaction between these two components. Materialization of ILs is truly a novel, promising research direction for both IL chemistry and materials science. In this article, we review recent advances in IL-based functional materials, focusing on smart and sensitive materials, optical materials, energetic materials, and IL/carbon hybrid materials.

Guanidinium‐based dicarboxylic acid ionic liquids for SO2 capture

“…SO 2 is one of today's main pollutants, so that the reversible capture of SO 2 from fossil fuels and the absorption of SO 2 from natural gas are industrial issues of environmental, economical, and technological concern. As a promising separation candidate media, ionic liquids (ILs) have attracted increasing interest due to their favorable properties suitable for SO 2 absorbents, such as negligible vapor pressure, high thermal stability, recyclability, and virtually limitless chemical tenability …”

An Overview on the Toxicological Properties of Ionic Liquids toward Microorganisms

“…They have remarkable features that can be easily custom‐made by a plethora of cations and anions, making them task‐specific solvents and agents. Because of these tailor‐made properties, ILs have been used in a wide variety of applications including biotechnology, chemical engineering, separation processes, material sciences, green chemistry, pharmaceutics, and many others. The use of ILs in biological applications has gained popularity in recent years because ILs are less toxic than that of many conventional organic solvents.…”

Self-lubricating, wear resistant protic ionic liquid-epoxy resin

“…Room-temperature ionic liquids (ILs) [11,12] contain bulk organic cations and organic or inorganic anions and show a unique combination of properties such as their low volatility, non-flammability, and their high thermal stability which are most relevant for tribological applications. ILs have shown excellent tribological performance, not only in lubrication of metal alloys and ceramic materials under severe sliding conditions [13][14][15][16][17][18][19][20][21][22][23][24][25], but also in the very difficult task of achieving the reduction of friction coefficients and wear rates of thermoplastic polymers and epoxy resins, where they have been used both as external lubricants and as additives [26][27][28][29][30][31][32][33][34][35][36][37][38][39][40]. Ionic liquids are also making an increasing impact in the field of polymer science, in particular on the development of new epoxy networks and composite materials by acting as curing agents, plasticizers, and as dispersants of nanophases in the epoxy matrix [35][36][37][38][39].…”