This Graphene Film Could Boiling Water in One Minute Under Natural Sunlight

Humans cannot drink saline water, like, sea water. But, saline water can be made into freshwater, for which there are many uses. The process is called “desalination”, and it is being used more and more around the world to provide people with needed freshwater.

A floating solar still is used to desalinate small amounts of seawater, using evaporation and condensation. (Credit: Landfall Navigation)

As the population continues to grow, shortages of freshwater will occur more often, if only in certain locations. In some areas, salt water (from the ocean, for instance) is being turned into freshwater for drinking.

The “simple” hurdle that must be overcome to turn seawater into freshwater is to remove the dissolved salt in seawater. That may seem as easy as just boiling some seawater in a pan, capturing the steam and condensing it back into water (distillation).

Other methods are available but these current technological processes must be done on a large scale to be useful to large populations, and the current processes are expensive, energy-intensive, and involve large-scale facilities.

A collaboration between three Australian universities has produced a new ultrathin film graphene metamaterial that could rapidly warms up to super high temperatures.

The film heats up to 160 degrees Celsius under natural sunlight within one minute.. It greatly open the possibility to be used in solar heating system, so that has potential to be used in generating desalination process, by boiling the seawater rapidly.

Swinburne University of Technology’s Professor Baohua Jia, who led the research, points to a few features that make the material so innovative.

“The absorption is coming from the sun and then converted to heat,” she told Create.

“So, basically, there is no external energy or electricity required.”

“The second feature is the absorption is really, really high,” Jia said.

“It’s only 90 nm, which is much thinner than other

What makes water saline?

What do we mean by “saline water?” Water that is saline contains significant amounts (referred to as “concentrations”) of dissolved salts. In this case, the concentration is the amount (by weight) of salt in water, as expressed in “parts per million” (ppm). If water has a concentration of 10,000 ppm of dissolved salts, then one percent of the weight of the water comes from dissolved salts.

Here are our parameters for saline water:

Freshwater – Less than 1,000 ppm
Slightly saline water – From 1,000 ppm to 3,000 ppm
Moderately saline water – From 3,000 ppm to 10,000 ppm
Highly saline water – From 10,000 ppm to 35,000 ppm

By the way, ocean water contains about 35,000 ppm of salt.