IIT-Gn team builds precise sieve for industry with molecular ‘donuts’ Premium

IIT-Gn develops a precise synthetic membrane for efficient molecular separation, enhancing water purification and carbon capture technologies.

Imagine trying to filter sand from pebbles using a fishing net: it won’t work because the holes are too big and uneven. In chemistry, separating molecules that are almost the same size is just as difficult. However, a new study from IIT-Gandhinagar has offered a solution: a synthetic membrane capable of distinguishing between molecules with sub-nanometer precision.

At the heart of the solution is a type of cluster called a polyoxometalate (POM). The researchers focused on a cluster named P8 that has a crown-like structure. Imagine it to be a small, rigid donut. The hole in its middle is exactly 1 nm wide.

The fixed size is perfect for a filter because it never changes, unlike the flexible, uneven holes in standard plastic filters.

The find is significant because accurate separation is essential to purify water, capture carbon, and to manufacture certain medicines.

The study was published in Journal of the American Chemical Society on January 13.

On their own, the POM clusters form brittle crystals that are tough to use as filters. Instead, the researchers attached ‘tails’ made of alkyl chains to them. The tails acted like shock absorbers and glue, allowing the clusters to self-assemble into large and flexible thin films called POMbranes.