Scientists have created the first ever porous liquid

[muriel_volestrangler]

You're probably familiar with porous rocks – rocks that can hold and filter liquids – and now scientists from Queen's University in Belfast have created a synthetic liquid with similar properties. The newly developed substance has a huge range of potential uses, including being able to capture harmful carbon emissions to prevent them from entering the Earth's atmosphere.

The porous liquid collects and absorbs gas through its pores, and researchers think it could open up new ways to collect and filter chemicals without relying on solid materials for the job: that obviously gives manufacturers and scientists much more flexibility.

The substance is still under development but the academics from Queen's University, together with colleagues from across the world, are confident in the results they've seen so far.

"Materials which contain permanent holes, or pores, are technologically important," explained Stuart James, one of the lead researchers. "They are used for manufacturing a range of products from plastic bottles to petrol. However, until recently, these porous materials have been solids."

http://www.sciencealert.com/scientists-have-created-the-first-ever-porous-liquid

Liquids with permanent porosity

Porous solids such as zeolites1 and metal–organic frameworks2, 3 are useful in molecular separation and in catalysis, but their solid nature can impose limitations. For example, liquid solvents, rather than porous solids, are the most mature technology for post-combustion capture of carbon dioxide because liquid circulation systems are more easily retrofitted to existing plants. Solid porous adsorbents offer major benefits, such as lower energy penalties in adsorption–desorption cycles4, but they are difficult to implement in conventional flow processes. Materials that combine the properties of fluidity and permanent porosity could therefore offer technological advantages, but permanent porosity is not associated with conventional liquids5. Here we report free-flowing liquids whose bulk properties are determined by their permanent porosity. To achieve this, we designed cage molecules6, 7 that provide a well-defined pore space and that are highly soluble in solvents whose molecules are too large to enter the pores. The concentration of unoccupied cages can thus be around 500 times greater than in other molecular solutions that contain cavities8, 9, 10, resulting in a marked change in bulk properties, such as an eightfold increase in the solubility of methane gas. Our results provide the basis for development of a new class of functional porous materials for chemical processes, and we present a one-step, multigram scale-up route for highly soluble ‘scrambled’ porous cages prepared from a mixture of commercially available reagents. The unifying design principle for these materials is the avoidance of functional groups that can penetrate into the molecular cage cavities.

http://www.nature.com/nature/journal/v527/n7577/full/nature16072.html

[JonathanRackham]

1. No lost volume.

A great place for ice