News from the NNI Community - Research Advances Funded by Agencies Participating in the NNI

Gold-silver alloys are useful catalysts that degrade environmental pollutants, facilitate the production of plastics and chemicals, and kill bacteria on surfaces. In nanoparticle form, these alloys could be useful as optical sensors or to catalyze hydrogen evolution reactions. But there's an issue: Silver doesn't always stay put. A new study by scientists at Rice University and the University of Duisburg-Essen in Germany has revealed a two-step mechanism behind silver's dissipation – a discovery that could help industry fine-tune nanoparticle alloys for specific uses.

Researchers at MIT have fabricated a hydrogel-based material that mimics the structure of the lobster's underbelly. The researchers ran the material through a battery of stretch and impact tests, and showed that, similar to the lobster underbelly, the synthetic material is remarkably "fatigue-resistant," able to withstand repeated stretches and strains without tearing. If the fabrication process could be significantly scaled up, materials made from nanofibrous hydrogels could be used to make straetchy and strong replacement tissues such as artificial tendons and ligaments.

Scientists at the U.S. Department of Energy’s Argonne National Laboratory have found a way to turn X-ray fluorescence into an ultra-high position-sensitive probe to measure tiny internal structures, called nanostructures, in thin films. In this technique, called X-ray waveguide fluorescence holography, the fluorescence emissions are enhanced and guided by the thin films themselves. The fluorescence reveals the evolution of nanostructures in real time with nearly atomic-level resolution, something no other technique has achieved.

Nanochannels have important biomedical and sensing applications. Although engineers have been making these tiny, tube-like structures for years, much remains unknown about their properties and behavior. Now, engineers at the University of Maryland have published surprising new findings. Using atomic-level simulations, the engineers have demonstrated that charge properties and charge-induced fluid flow within a functionalized nanochannel don’t always behave as expected.

Researchers at The Ohio State University have developed a new tool that can design more complex DNA robots and nanodevices than were ever possible before in a fraction of the time. The software helps researchers design ways to take strands of DNA and combine them into complex structures with rotors and hinges that can move and complete a variety of tasks, including drug delivery.

Researchers at the University of California, Berkeley, and the U.S. Department of Energy’s Lawrence Berkeley National Laboratory and Sandia National Laboratories have discovered a way to simplify the removal of toxic metals, such as mercury and boron, during water desalination, while at the same time potentially capturing valuable metals, such as gold. The researchers synthesized flexible polymer membranes with embedded nanoparticles that can be tuned to absorb specific metal ions – gold or uranium ions, for example. The new technique, which can easily be added to current membrane-based electrodialysis desalination processes, removes nearly 100% of these toxic metals, producing a pure brine along with pure water and isolating the valuable metals for later use or disposal.

In an effort to curb global warming, engineers at Purdue University have created the whitest paint yet. Coating buildings with this paint may one day cool them off enough to reduce the need for air conditioning, the researchers say. The new paint formulation, which contains barium sulfate nanoparticles, reflects up to 98.1% of sunlight—compared with the 95.5% of sunlight reflected by the researchers' previous ultra-white paint—and sends infrared heat away from a surface at the same time. 

Biomedical engineers at Duke University have developed a self-assembling nanomaterial that can help limit damage caused by inflammatory diseases by activating key cells in the immune system. In mouse models of psoriasis, the team showed that their nanofiber-based drug could effectively mitigate damaging inflammation as effectively as a gold-standard therapy.

Mathematicians and engineers at the University of Utah have shown how ultrasound waves can organize carbon nanoparticles in water into a pattern that never repeats. The results, they say, could result in materials called "quasicrystals," with custom magnetic or electrical properties. This discovery might lead to materials that can manipulate electromagnetic waves, such as those used by 5G cellular technology.

Creating a two-dimensional (2D) material, just a few atoms thick, is often an arduous process requiring sophisticated equipment. So, scientists were surprised to see 2D puddles emerge inside a three-dimensional (3D) superconductor – a material that allows electrons to travel with 100% efficiency and zero resistance – with no prompting. Within those puddles, superconducting electrons acted as if they were confined inside an incredibly thin, sheet-like plane. The results have practical implications for creating 2D materials.