A new membrane which, according to the press release presenting the study published in Nature Nanotechnology, “can produce one hundred times more energy from sea water”, was created by a group of chemists from the University of Leiden. The new membrane is ultra-thin and only one molecule thick.
It is a membrane that, once introduced into the water, can absorb the energy coming from the particles moving from one side to the other, which happens very easily when salt water comes into contact with fresh water because there is an exchange of salt. This is the same process that is usually used to desalinate sea water.
The new membrane developed by the chemists in Leiden, however, is much more efficient because it produces 100 times more energy than “classic” membranes.
The membrane is made of carbon and is porous and thin at the same time, unlike the more common membranes which are either porous or thin.
The membrane was created by spreading oily molecules on the surface of the water. It then formed a film which, once heated, saw the creation of a stable porous membrane.
“The membrane we created is only two nanometres thick and is permeable to potassium ions. We can modify the properties of the membrane using a different molecular block. In this way we can adapt it to meet any requirement,” says Xue Liu, one of the authors of the study and the creators of the membrane together with his colleague Grégory Schneider.
The new membrane is similar to graphene but at the same time different from this material, as Schneider himself explains: “When making a membrane, many researchers start with graphene, which is very thin but not porous. Then they try to drill holes to make it more permeable. We did the opposite by assembling small molecules and building a larger porous membrane from those molecules. Compared to graphene, it contains imperfections, but that’s what gives it its special properties.