Iron nanoparticles 1,000 times thinner than a human hair have shown an unprecedented ability to clean contaminated groundwater since they were invented 10 years ago at Lehigh University.
Image of a freshly prepared iron nanoparticles in a layer of palladium.
The palladium coated particles are cured more than 50 toxic waste sites in the United States and other countries at a tenth of the time and greater economies of scale that traditional methods of “pump and treated.”
Now, with electron microscopy and spectroscopy facilities Lehigh, investigators have gained unprecedented knowledge that could improve efficiency and expand the applications of nanoparticles powerful.
The researchers used an electron microscope scanning transmission (STEM acronym in English) and energy dispersive spectroscopy X-ray (XEDS by its acronym in English) to capture, for the first time, the evolution of the nanostructure of the particles bimetallic when they remove pollutants in water.
The advanced instruments for imaging at Lehigh capture stunning detail of the reactions within the nanoparticles. As react with pollutants such as trichloroethene (TCE), a toxic industrial solvent, nanoparticles show large structural changes. The core of the particles become smaller, iron diffuses outward, and palladium, a catalyst that makes up 1 percent of the mass of the particle, moves from the outer surface of the inner surface of the iron.
Writing earlier this month in Environmental Science and Technology (ES & T), the magazine number one in their field, researchers from Lehigh reported that the ability of nanoparticles to eliminate toxins decreases as the particles “age” and subjected to structural change with exposure to water.
Their findings, they wrote, suggest that the age of nanoparticles and the storage environment play a key role in influencing their effectiveness as agents of remediation.
