Eureka! Magic potions for a greener environment
Solid + solid = liquid
Dr Andrew Abbott, Dr David Davies and Dr Paul Jenkins.
University of Leicester.
Dr Gregor Rozenburg.
Imagine making a liquid just by mixing two solids. And think what you could do with this liquid if it was non-toxic, biodegradable and could dissolve a wide range of materials. Chemists at the University of Leicester are making just such a series of liquids that can be used to substitute the strong and corrosive acids traditionally used as solvents in many industrial chemical reactions. Safer industrial metal coatings and shinier cars are just two of the possible spin-offs from this research.
Mixing an ingredient of chicken feed (choline chloride) with a common fertiliser (urea) is all that it takes to make an ionic liquid. Changing the ingredients, or modifying the relative ratios of the mixture, can alter the physical properties of the liquid, such as its electrical conductivity. Electroplating, electropolishing and metal extraction are just some of the chemical processes that might be improved by substituting ionic liquids for the organic solvents currently used.
The liquids can be used to dissolve a wide range of metals, polymers, sugars and salts, and are in a class of their own when it comes to their solvent properties. They are non-volatile, so their use dramatically improves conditions for those who have to work with solvents. They remain liquid over a wide range of temperatures. They solubilise compounds that would otherwise need highly caustic or corrosive solvents to dissolve. They can be produced and stored cheaply by selecting the right basic ingredients. And they are biodegradable.
The scientists are working with a consortium of academic and commercial partners to develop the technologies on an industrial scale, and to test them by electroplating high-tech pieces of aircraft. The project has recently been awarded a Government grant under the Sustainable Technology Initiative, and Andy Abbott is enthusiastic about the benefits it could bring: 'Finding ways to scale up the benefits of ionic liquids means that we may soon be able to use them in real-life industrial processes. They could make things cheaper, easier, safer and more environmentally friendly.'
Applications for the technology include improving the chromium plating process widely used to provide a safe durable coating to equipment in almost every industry, from medical instruments to the kitchen sink.