Researchers from Australia and China have developed an ultrathin sieve membrane from 2D nanosheets. According to the researchers, these membranes can filter the potentially harmful ions like mercury and lead from water.
The nanosheets are highly porous as they are developed using water-stable Metal-Organic Frameworks (MOFs). Also, MOFs extends the potential to deliver clean water to people through purification and desalination processes. Also, it separates gases and solvents.
These nanosheets are made from water-stable monolater aluminium tetra-(4-carboxyphenyl) porphyrin frameworks, also called AI- MOFs. This exfoliated to just a nanoscale thickness: one thousand-millionths of a metre.
A research co-leader, Xiwang Zhang, says, “[That was] a daunting challenge. [MOF membranes] are typically thick and suffer from insufficient hydrolytic stability.”
Also, a team led by Australia’s Monash University and Australia’s Nuclear Science & Technology Organisation (ANSTO) wrote in a journal Science Advances that, during testing of the membrane, membrane performed well for 750+ hours using a limited amount of energy.
The study suggests the the widespread use of polymers is because of their low cost and easy processability.
Traditional polymeric membranes usually lead to limited selcetivity as they contain a dense selective layer. The benefit of using a naoporous membrane is that they overcome the limitation that is faced while using traditional polymeric.
Oinfen Gu, ANSTO and co-lead author of the study, says “We use an instrument called the Powder Diffraction beamline at ANSTO’s Australian Synchrotron to understand the difference between the molecular structure of nanosheet samples, and samples at different temperatures, in order to test water purification performance.”
He adds, “The technique, called in-situ, high-temperature powder X-ray diffraction characterisation, was conducted on the nanosheets, and during the process there were no obvious variations in the samples at increasing temperature, demonstrating their robustness.”
The new study that involves the analysis suggests that intrinsic nanopores of AI-MOFs nanosheets can be of great help. These nanosheets eases the ion and water separation, providing clean water, by creating vertically aligned channels, acting as a main transportation way for water molecules.