Category: U.S. National Science Foundation

  • Researchers record ultrafast chorus dance of electrons on super-small particle

    (Funded by the U.S. Department of Energy and the U.S. National Science Foundation)
    Researchers from the U.S. Department of Energy’s SLAC National Accelerator Laboratory; Villanova University; Northwest Missouri State University; Deutsches Elektronen-Synchrotron DESY in Hamburg, Germany; the Max Planck Institute of Quantum Optics in Garching, Germany; the Max Planck Institute for the Structure and Dynamics of Matter in Hamburg, Germany; the Institute for Photonics and Nanotechnologies in Milano, Italy; and Politecnico di Milano in Italy have observed how electrons, excited by ultrafast light pulses, danced in unison around fullerene (C60) molecules. Researchers measured this dance with unprecedented precision, achieving the first measurement of its kind at the sub-nanometer scale. The synchronized dance of electrons, known as plasmonic resonance, can confine light for brief periods of time. While they’ve been studied extensively in systems from several centimeters across to those just 10 nanometers wide, this is the first time researchers were able to break the field’s “nanometer barrier.”

  • Light-Powered Breakthrough Enables Precision Tuning of Quantum Dots

    (Funded by the U.S. National Science Foundation)
    Researchers at North Carolina State University have demonstrated a new technique that uses light to tune the optical properties of quantum dots. The researchers placed green-emitting perovskite quantum dots in a solution containing either chlorine or iodine. The solution was then run through a microfluidic system that incorporated a light source. The microfluidic environment enabled precise reaction control by ensuring uniform light exposure across small solution volumes, approximately 10 microliters per reaction droplet. The light triggered reactions that made the green-emitting perovskite quantum dots move closer to the blue end of the spectrum when chlorine was present in the solvent and closer to the red end of the spectrum when iodine was present in the solvent.

  • Air inside your home may be more polluted than outside due to everyday chemical products

    (Funded by the U.S. National Science Foundation)
    Engineers from Purdue University and GRIMM Aerosol Technik Ainring GmbH & Co. in Germany have found that chemical products from air fresheners, wax melts, floor cleaners, and deodorants can rapidly fill the air with nanoparticles that are small enough to get deep into our lungs. These nanoparticles form when fragrances interact with ozone, which enters buildings through ventilation systems. “Our research shows that fragranced products are not just passive sources of pleasant scents—they actively alter indoor air chemistry, leading to the formation of nanoparticles at concentrations that could have significant health implications,” said Nusrat Jung, one of the engineers involved in this study.

  • Collection of tiny antennas can amplify and control light polarized in any direction

    (Funded by the U.S. National Science Foundation)
    Researchers at Washington University in St. Louis have developed ultra-thin materials, called metasurfaces, that can amplify and interact with light regardless of its polarization. The metasurfaces are made of tiny nanoantennas that can both amplify and control light in very precise ways and could replace conventional refractive surfaces in eyeglasses and smartphone lenses. The polarization-independent metasurfaces have what’s known as a high quality factor, which means they trap light over a narrow band of resonant frequencies for a long time, generating a strong response to external stimuli.

  • Stormwater pollution sucked up by specialized sponge

    (Funded by the U.S. National Science Foundation)
    Researchers from Northwestern University have defined a method to tailor a sponge that is coated with nanoparticles to specific Chicago pollutants and then to selectively release them. In its first iteration, the sponge platform was made of polyurethane and coated with a substance that attracted oil and repelled water. The newest version is a highly hydrophilic (water-loving) cellulose sponge coated with nanoparticles tailored to other pollutants. The scientists found that by lowering the pH, metals flush out of the sponge. Once copper and zinc are removed, the pH is then raised, at which point phosphate comes off the sponge. Even after five cycles of collecting and removing minerals, the sponge worked just as well, and the resulting water had untraceable amounts of pollutants.