The multilayered carbon nanotube / polyamide nano-composite membrane developed by Shinshu University’s Global Aqua Innovation Center (COI) has been shown to have excellent antifouling properties that is less susceptible to caking with natural organic substances. The results of this study was published in Environmental Science & Technology (online) of the American Chemical Society.

Most of the world's seawater desalination is processed by reverse osmosis membranes.
It's biggest issue is membrane fouling in which various impurities present in the seawater are deposited on the surface of the membrane.

The nanocarbon membrane developed by this center had previously been demonstrated to be resistant to soiling by organic protein and inorganic calcium carbonate. This new study was able to shed light on its resistance to natural organic matter fouling.

Humic acids from decomposing plants and alginates of polysaccharides from seaweed are common natural organic matter found in the ocean and river water. They stick to the membrane and is difficult to remove once it is absorbed by the membrane and fouling occurs.

This press conference announced the use of the university’s supercomputer to conduct simulation experiments of molecular dynamics to get to the bottom of how the membrane fouling initially occurs. By elucidating the mechanism of the fouling on a molecular level, they were able to develop a new membrane with relevant properties, one resistant to collecting natural organic matter.

(Top: Commercially available membrane Below: Shinshu University COI developed membrane. Shinshu’s membrane is more resistant to humic acid stains and easier to clean)