New Nanofiber Membrane Removes 99.9% of Salt from Seawater Cheaply and Efficiently

August 26, 2021 at 9:41 pm

Korean engineers develop nanofiber material that desalinates 15 times more efficiently than conventional saltwater distillers


Korean scientists have taken microfiber to a new level – nanofiber – and it works great for filtering salt out of seawater!

Distilling saltwater is nothing new, but until now it’s been an extremely inefficient process.

The materials used to filter the salt absorbed too much water, making them soggy and porous. They could only be used for about 2 days before salt and pollutants started leaking through along with the water.

So researchers at the Korea Institute of Civil Engineering & Building Technology came up with a new filtration material called “co-axially electrospun superhydrophobic nanofiber membrane.”

As its name suggests, water is quickly transferred from one side of the material to the other without being absorbed. And salt can’t get through the he tightly knit nanofibers.

A rough polymer surface on one side of the membrane repels the water, while a silica aerogel acts like a thermal insulator on the other side, keeping the cold side of the distiller from getting warmed up by the hot side. This keeps the difference in vapor pressure high, making the membrane more efficient.

And it lasts 30 days, compared to 2 days, before needing to be dried or replaced (due to absorbing too much water and becoming too porous to keep salt out), making it 15 times more efficient.

“The co-axial electrospun nanofiber membrane has strong potential for the treatment of seawater solutions without suffering from wetting issues and may be appropriate for real-scale membrane distillation applications,” materials scientist Dr. Yunchul Woo said in a paper about his new invention.

Currently, the most popular method of purifying sea water is reverse osmosis at about 20,000 desalination plants around the world. But these facilities require vast amounts of electricity and typically dump the waste product (a concentrated brine) back into the sea.