Scientists at the University of Illinois have created a game-changer for hydration by stripping salt from a sample of saltwater with the help of nanopores.
The team at Illinois initiated the process of reverse osmosis by passing large amounts of water through a sheet of molybdenum disulfide (MoS2) only a nanometer thick — like passing running water from a stream through a sieve to find a piece of river gold. The nanopores within the sheet strained the water for salt and any other contaminants, producing crystal-clear, drinkable H2O.
"Finding materials for efficient desalination has been a big issue, and I think this work lays the foundation for next-generation materials," said Nayanara Aluru, a professor of mechanical science and engineering at Illinois, in an official statement released by the university. "These materials are efficient in terms of energy usage and fouling, which are issues that have plagued desalination technology for a long time."
The nanopores within the sheet were made possible by the MoS2 molecules themselves, which are structured with one one molybdenum atom interceded between two sulfur atoms; subsequently, a sheet of MoS2 atoms creates two outside layers of sulfur with an inside layer of molybdenum. When the scientists created pores within the sheet, the molecules formed a naked circle of molybdenum around the center of each nanopore fashioned in the shape of a nozzle, which created a siphon that could strain massive amounts of salt water and strip it of compounds harmful to the human body.
Amir Barati Farimani, a postdoctoral fellow at Stanford University who worked on the study as a graduate student, explained how nanotechnology could play a huge part toward reducing costs associated with desalination plants. He also raised a key application for the use of MoS2: using the desalination to provide water for regions suffering from intense periods of drought.
"I'm in California now, and there's a lot of talk about the drought and how to tackle it. I'm very hopeful that this work can help the designers of desalination plants. This type of thin membrane can increase return on investment because they are much more energy efficient," Farimani added.
Photo: Angewandte Chemie | Flickr