A computer model
of a nanopore in a single-layer sheet of MoS2 shows that
high volumes of
water can pass through the pore using less pressure than
standard plastic
membranes. Salt water is shown on the left, fresh water on the right.
(November 11, 2015) University
of Illinois engineers have found an energy-efficient material for removing salt
from seawater that could provide a rebuttal to poet Samuel Taylor Coleridge’s
lament, “Water, water, every where, nor any drop to drink.”
The material, a nanometer-thick sheet of molybdenum
disulfide (MoS2) riddled with tiny holes called nanopores, is specially
designed to let high volumes of water through but keep salt and other
contaminates out, a process called desalination. In a study published in the
journal Nature Communications, the Illinois team modeled various thin-film
membranes and found that MoS2 showed the greatest efficiency, filtering through
up to 70 percent more water than graphene membranes.
“Even though we have a lot of water on this planet, there is
very little that is drinkable,” said study leader Narayana Aluru, a U. of I.
professor of mechanical science and engineering. “If we could find a low-cost,
efficient way to purify sea water, we would be making good strides in solving
the water crisis.