Applications of ionic Liquids: Fate, Prospects, and Perspectives

The unique physicochemical properties and versatility of ionic liquids have earned them names like “green solvents, designer solvents, and solvents for the future”. Ionic liquids have been widely used as alternatives to traditional solvents for different applications. Ionic liquids are organic containing salts with melting points below 100 °C, comprised of tunable cations and anions that have found relevance in industrial applications such as separations, nanotechnology, electrochemistry, catalysis, and analytical chemistry, to name a few. However, despite the ubiquitous applications across various industries, there is a paucity of information about the toxicity, environmental impact, and potential impacts to public health. Hence, in this study, the various applications of ionic liquids at bench-, pilot-, and industrial-scales have been elucidated based on fate in the ecosystem and toxicity to plants, animals, and humans. The literature review has also included a life cycle assessment of ionic liquid processes. Limitations such as cost, synthesis, energy, and environmental impacts associated with using ionic liquids as alternative solvents for industrial applications were also identified; especially, the early generations of ionic liquids. Finally, this study has proposed strategies for synthesizing the next generation of ionic liquids with low toxicity, high biodegradability, low cost, and low environmental impact.