A desalination membrane works to filter salty water; salty water is gushed through the membrane, to obtain clean water suitable for several uses. Though the process looks simple what is desired, it has complex details that have baffled researchers for decades till date.
To throw light on this, a team of researchers have published a key finding in the online version of Science of Dec 31, 2020 to understand how membranes function to filter minerals from water.
“In fact, despite being used for many years, how filtration membranes function in not known,” said one of the research associates. To understand this, during a scientific study, researchers found how the density distribution of the membrane itself is controlled at the nanoscale is very important for the performance of water produced.
For the study, the research team used multimodal electron microscopy. This technique combines atomic-scale detailed imaging with methods that reveal chemical composition, to point out inconsistent density and mass of desalination membranes.
Researchers employed precise apparatus to comprehend mass and density aspects of membranes
To establish this, the density variations of desalination membranes mapped in polymer film in 3-D with a spatial resolution of almost one nanometer. The length of the nanometer is less than half that of the diameter of a DNA strand. This technological advancement is a key understanding the role density plays in membranes.
For example, in a filter coffee, it can be seen just through the naked eye how some places are more dense and some less. In fact, for filtration membranes, though it looks even, but it’s not so at the nanoscale, and how the mass distribution is controlled is very important for the performance of water filtration.