The new filtration method ensures the safety of drinking water and improves industrial production

A team of scientists from the School of Engineering at Tufts University, inspired by biology, has developed a new filtration technology that can help curb a drinking-related disease that affects tens of millions of people around the world, and has the potential to improve environmental restoration , Industrial and chemical production and mining, other processes

The researchers published a report in the Proceedings of the National Academy of Sciences that their new polymer membrane can separate fluorine from chlorine and other ions (charged atoms), with selectivity other than other methods.

It is well known that adding fluoride to the water supply can reduce the incidence of tooth decay, including tooth decay

The ability to use relatively inexpensive filter membranes to remove fluoride can protect the community without the need to use high-pressure filtration or must completely remove all components before mineralizing drinking water

Ayse Asatekin, associate professor of chemical and biological engineering in the School of Engineering, said: "The potential of ion selective membranes in reducing excess fluoride in drinking water is very encouraging

Asatekin said, for example, this process could theoretically increase the production of lithium from limited geological reserves for sustainable lithium battery production, or the production of uranium for nuclear power generation.

When developing the design of the synthetic membrane, Asatekin's team was inspired by biology

The biological ion channel creates a more selective environment for the passage of these small ions, by arranging functional chemical groups with different sizes and charges and different affinities for water in the channel

The filter membrane made by the Asatekin team is designed by coating a zwitterionic polymer (a polymer with tightly connected positive and negative charges on the surface) on a porous scaffold, forming a membrane with a narrower channel than nanometers, surrounded by Hydrophobic and positively and negatively charged chemical groups

At present, most filter membranes separate molecules by the significant difference in particle or molecular size and charge, but it is difficult to distinguish individual atomic ions because their size and charge are almost the same

In contrast, the Tufts University researchers’ membrane can separate ions that differ by only a small fraction of their atomic diameters, even if their charges are almost the same.

The Cambridge-based Zwitterco company funded this research, and the company will explore the large-scale production of ion separation membranes to test its application in industrial environments