Scientists at Queen’s University Belfast Create First Ever ‘Porous Liquid’

“Because of the empty holes we then had in the liquid, we found that it was able to dissolve unusually large amounts of gas”.

But according to Mastalerz, the surface area and the overall uptake of gases in the porous liquids are still much lower than those in most zeolites and MOFs. They are used for manufacturing a range of products from plastic bottles to petrol. However, until recently, these porous materials have been solids. The new invention is considered quite an important breakthrough as previously discovered porous materials have been solid.

The way the team designed the new material was by creating cage molecules in order to use them for the experiment.

The key feature of this new liquid is that it is porous. The results of their research are published today in the journal Nature.

The solvent picked for the study was the crown ether 15-crown-5, and the cages were created to fit the molecules of carbon dioxide, methane, nitrogen and xenon. ‘Usually, long or branched alky chains are employed to increase the solubility or lower the melting point of a larger molecule, but linear alkyl chains can penetrate into the cavities of adjacent molecules, resulting in non-porous liquids. These molecules provide well-defined amounts of porosity and are dissolved in an organic solvent which provides fluidity, they said. The porous liquid they developed has hundreds of times the porosity of conventional liquids. To achieve high solubility in the bulky solvent, the team functionalised each cage with six crown ether groups. ‘At the moment this material can not compete with those solids, ‘ he says, adding that permanently porous liquids should instead be seen as a prototype of a new class of substance.

“What we have done is to design a special liquid from the “bottom-up” – we designed the shapes of the molecules which make up the liquid so that the liquid could not fill up all the space”, explained Professor Stuart James from the university’s School of Chemistry and Chemical Engineering.

Porous liquids could also be used as an effective gas separator.

Take that a step further with regards to what scientists at Queens University of Belfast have created, we could be looking at a liquid with space to soak up greenhouse gases or other forms of pollution.

The study was financed by the Engineering Physical Science Research Council (the UK’s main agency for funding research in engineering and the physical sciences) and the Leverhulme Trust.