"Nature," she said of her table-top illustration, "doesn't want lots of little things." So Thiel grabbed the smaller things and slid them into a single pile next to the bigger tissue box. "Nature wants one big thing all together, like this."
Thiel, an Iowa State Distinguished Professor of Chemistry and a faculty scientist for the U.S. Department of Energy's Ames Laboratory, and James Evans, an Iowa State professor of physics and astronomy and a faculty scientist for the Ames Laboratory, describe that process in the Oct. 29 issue of the journal Science.
The paper, "A Little Chemistry Helps the Big Get Bigger," is in the journal's Perspectives section. It describes a process called coarsening. That's when "a group of objects of different sizes transforms into fewer objects with larger average size, such that 'the big get bigger,'" says the paper. Examples of the process include the geologic formation of gemstones, the degradation of pharmaceutical suspensions and the manufacture of structural steels.
Thiel and Evans were invited to write the paper after Thiel delivered a talk at an American Chemical Society meeting about their studies of coarsening, an emerging field in surface chemistry.
Thiel worked with Mingmin Shen, a former Iowa State doctoral student who is now a post-doctoral research associate at Pacific Northwest National Laboratory in Richland, Wash., on the experimental side of the coarsening research. Evans worked with Da-Jiang Liu, an associate scientist at the Ames Laboratory, on the theoretical side of the project.
The researchers, with the support of grants from the National Science Foundation, have been using scanning tunneling microscope technology – an instrument that allows them to see individual atoms – to study how coarsening happens on the surface of objects.
They've studied nanoscale particles grown on the surface of silver and how adding sulfur can increase coarsening. They're trying to learn the mechanism of that increase and understand the nature of the messengers that move atoms during the coarsening process.
What Thiel and Evans are looking for is a general principle that explains what they call additive-enhanced coarsening. To do that, Thiel said they still need to collect and analyze data from more coarsening systems.
Evans said a better understanding of the coarsening process can help researchers develop small structures – including nanoscale technologies, catalysts or drug suspensions – that resist coarsening and are therefore more durable. A better understanding could also help researchers manipulate coarsening to develop structures with a very narrow distribution of particle sizes, something important to some nanotechnologies.
"When we're building something on a small scale, for it to be useful, it has to be robust, it has to survive," Evans said. "And one thing we're looking at is the stability of the very tiny structures that are crucial to nanoscale technologies."
Biologists unravel another mystery of what makes DNA go 'loopy'
16.03.2018 | Emory Health Sciences
Scientists map the portal to the cell's nucleus
16.03.2018 | Rockefeller University
Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...
On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...
The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...
At the 2018 ILA Berlin Air Show from April 25–29, the Fraunhofer Institute for Laser Technology ILT is showcasing extreme high-speed Laser Material Deposition (EHLA): A video documents how for metal components that are highly loaded, EHLA has already proved itself as an alternative to hard chrome plating, which is now allowed only under special conditions.
When the EU restricted the use of hexavalent chromium compounds to special applications requiring authorization, the move prompted a rethink in the surface...
At the ILA Berlin, hall 4, booth 202, Fraunhofer FHR will present two radar sensors for navigation support of drones. The sensors are valuable components in the implementation of autonomous flying drones: they function as obstacle detectors to prevent collisions. Radar sensors also operate reliably in restricted visibility, e.g. in foggy or dusty conditions. Due to their ability to measure distances with high precision, the radar sensors can also be used as altimeters when other sources of information such as barometers or GPS are not available or cannot operate optimally.
Drones play an increasingly important role in the area of logistics and services. Well-known logistic companies place great hope in these compact, aerial...
16.03.2018 | Event News
13.03.2018 | Event News
08.03.2018 | Event News
16.03.2018 | Earth Sciences
16.03.2018 | Physics and Astronomy
16.03.2018 | Life Sciences