Graphene is taking the role of Zeus in the fraternity of materials. Its astounding properties come to the fore every time researchers try to do something new with it. Interestingly this time, the material has shown its ‘romantic inclination’ towards water.
Its hydrophobic nature allows graphene to repel water however, narrow capillaries fabricated from the material reverses the nature of the same material, turning it into hydrophilic. Rapid permeation occurs when the layer of water molecule is of same dimension as that of graphene itself, that is, one atomic thickness.
This new and unique property of graphene has acted as a magnet for water filtration and desalination technologies and researchers are working towards gaining more insights into the subject.
In terms of investment, the newly evolved singular atomic layer capillaries would be cheap relatively and easier to obtain. The method employed would use the layers of graphene oxide over one another. Structure of the resulted stacks obtained resembled to nacre (mother of pearl), which also happens to be equally strong.
Two years back, researchers from the University of Manchester investigated and proved that thin films of similar laminates did not allow gases (including helium) and vapors to pass through but water could easily make its way without resistance. Taking their research to next level, the same team explored the mechanism with graphene.
The team was were able to prove that if thin stacks of graphene were placed in water, it did allow two monolayers of water to cross through and at the same time, the laminates became swollen too. The lattice allowed salts that were not more than nine Angstroms in size and rest were simply rejected. The mesh of graphene was able to detect the varied sizes of atomic species and hence allowed only the lesser sizes atoms to pass through.
The ultraprecise separation was coupled with ultrafast mechanism. Researchers called the process as “ion sponging”. The suction effect of the capillaries made the internal environment highly saturated leaving the salty solutions at the outside.
Researchers envision that by reducing the mesh size of the graphene layers, they would be able to bring about a controlled mechanism for filtering out the salty seawater and so far, they are positive about the expected outcome.
The research does sound inspiring especially when we lack water quality. And with this we might be able to save the most critical endangered resource.