Researchers Develop a Productive Nanodevice, Likely To Filter Proton and Alkaline Metal Ions

Scientists at Monash University have created a faster, more effective nanodevice for filtering proton and alkaline metal ions, which will aid in the development of next-generation membranes for clean energy conversion and storage.

The new nanodevice has atomic-scale precision and uses reverse electrodialysis to generate its own electricity.

A research team led by Australian Laureate Fellow Professor Huanting Wang from Monash University discovered that a metal-organic framework (MIL-53-COOH)-polymer nanofluidic device superficially resembles the features of both biological inward-rectifying potassium channels and outward-rectifying proton channels in a report published in the distinguished peer-reviewed journal Science Advances.

Professor Wang, who led the project with research fellow Dr. Jun Lu from Monash University’s Department of Chemical and Biological Engineering, states “It has important real-world implications, particularly for designing next-generation membranes for clean energy technology, energy conversion and storage, sustainable mining and manufacturing, with specific applications in acid and mineral recovery.”

Potassium channels are the most common type of ion channel and can be found in almost every living organism. One of the key functions of biological ion channels in cell membranes is positional ultrafast ion transport with atomic-scale precision.

These biological ion channels work together to keep the electrolyte and pH balance throughout cell membranes, which is critical for the cells’ physiological functions.

Electrolyte concentration disorders in cells, particularly for positively charged ions like potassium, sodium and proton, are known to have a direct connection with diseases like epilepsy.

Artificial nanochannel devices made of porous materials have been extensively researched for the experimental program of nanofluidic ion transport to attain the ion-specific transport features observed in biological ion channels, as a result of these functionalities.

Carbon nanotubes, graphene, polymers and metal-organic frameworks (MOFs), for example, have been utilized to create nanometer-sized pores that imitate atomic-scale ionic and molecular transport in biological ion channels.

However, till now, no one has announced the development of bioinspired ultrafast resolving counter-directional transport of proton and metal ions.

The unprecedented ion-specific rectifying transport behavior found in our metal-organic framework (MIL-53-COOH)-polymer nanofluidic device is attributed to two distinct mechanisms for metal ions and proton, explained by theoretical simulations. This work furthers our knowledge of designing artificial ion channels, which is important to the fields of nanofluidics, membrane and separations science.

Wang, Study Lead and Professor, Monash University

“This is an exciting fundamental finding and we hope it stimulates more research into these important areas,” concluded Professor Wang.

Journal Reference:

Lu, J., et al. (2022) Ultrafast rectifying counter-directional transport of proton and metal ions in metal-organic framework–based nanochannels. Sciences Advances. doi.org/10.1126/sciadv.abl5070.