Ionic Liquids from ITQB in Nature
Oeiras, 16/02/06
The Laboratory of Molecular Thermodynamics, headed by Professor Luis Paulo Rebelo, has just published a paper in Nature for their work with ionic liquids. You can find below a brief description of the paper or take a look at the paper itself by following the link displayed at the end.
This paper has received a particular attention from Nature: it has been featured in News and Views, by Peter Wasserscheid, an authority in the subject of Ionic Liquids, and it has been selected as one of the papers presented in Nature Podcast, a weekly audio show featuring highlights from news and articles published in Nature, that this week includes an interview with Luis Paulo Rebelo. Also because of this paper, you will find in the initial pages of this week’s Nature a section entitled Quantified: Portugal.
Green chemistry: Ionic liquids are a gas
Ionic liquids have been advocated as 'green' solvents for industrial chemistry, because they were thought not to evaporate at all, and thus to release no toxic fumes. But that's not quite so, according to Luís Rebelo and colleagues in this week's Nature. They show that some ionic liquids do indeed evaporate, and can therefore be distilled.
This does not undermine the green credentials of these liquids, which are composed of charged ions rather than neutral molecules like most ordinary liquids. The various ionic liquids that Rebelo and colleagues have investigated do have very low volatility - very little vapour escapes from the surface of the liquid. But if heated to between 200 and 300 oC, the liquids will evaporate and then condense again when cooled.
That is a good thing, the researchers say, because it means that distillation can be used to purify the liquids. This will allow them to be recycled when they are used as solvents. The belief that such distillation was not possible has prevented the use of ionic liquids in some applications where they would otherwise be beneficial.
Original Paper: The distillation and volatility of ionic liquids
News and Views: Chemistry - Volatile times for ionic liquids
