Scientists from Russia and China discovered a host of new and unexpected nanoparticles and found a way to control their composition and properties the findings that break fresh ground in the use of nanoparticles. The results of their study were published in Physical Chemistry Chemical Physics journal.
Micro objects, such as nanoparticles, can differ a lot from macro objects (crystals, glasses) in terms of chemical composition and properties. The two pillars that the nanotechnology rests upon are the wide diversity of properties that nanoparticles of the same material (for example, silicon oxide) but of varying sizes, and the ability to control its properties.
However, both experimental and theoretical research into the structure and composition of nanoparticles encounters major difficulties.
Using the USPEX evolutionary algorithm developed by Artem R. Oganov, professor at Skoltech and MIPT, scientists from China and Russia studied a wide range of nanoparticle compositions and in particular examined two classes of nanoparticles essential for catalysis: iron-oxygen and cerium-oxygen.
They discovered that the so-called "magic nanoparticles" that display enhanced stability can have unexpected chemical compositions, for example, Fe6O4, Fe2O6, Fe4O14, Ce5O6, and Ce3O12. Oxygen-rich nanoparticles, such as Fe4O14, stable at normal conditions, may explain carcinogenicity of oxide nanoparticles. Scientists have quantitatively explored how the compositions vary by changing the temperature or partial pressure of oxygen.
"Stable nanoclusters can possess strange and unexpected chemical compositions (for example, Si4O18 or Ce3O12) at normal conditions, while for crystals this is usually found at extreme conditions, such as high pressures", - says Xiaohu Yu, the first author of this work, Associate Professor of Shaanxi University of Technology and former member of the Oganov lab in MIPT.
"The fact that nanoparticles have virtually the same ridges, islands of stability and seas of instability as atomic nuclei came as a surprise in this study.
The atomic nucleus and the nanoparticle alike can be described as a cluster of two types of particles, for example, iron and oxygen in our case, or protons and neutrons in the case of atomic nuclei. If you draw a map and plot the numbers of each kind of atoms in the cluster along its axes, you will see that the majority of stable clusters form narrow ridges of stability.
You will also discover islands of stability that are quite curious from the chemical point of view. It is quite conceivable that stable nanoparticles serve as elementary building blocks in crystal growth ? the topic I've been thrilled about since my school years.
As for the islands of stability, the great contributors to their study were our renowned academicians Flerov and Oganesyan that I dreamt of working with when I was a kid," said Oganov.
Ilyana Zolotareva | EurekAlert!
How molecules teeter in a laser field
18.01.2019 | Forschungsverbund Berlin
Discovery of enhanced bone growth could lead to new treatments for osteoporosis
18.01.2019 | University of California - Los Angeles
The scientific and political community alike stress the importance of German Antarctic research
Joint Press Release from the BMBF and AWI
The Antarctic is a frigid continent south of the Antarctic Circle, where researchers are the only inhabitants. Despite the hostile conditions, here the Alfred...
World first experiments on sensor that may revolutionise everything from medical devices to unmanned vehicles
The new sensor - capable of detecting vibrations of living cells - may revolutionise everything from medical devices to unmanned vehicles.
Dead and alive at the same time? Researchers at the Max Planck Institute of Quantum Optics have implemented Erwin Schrödinger’s paradoxical gedanken experiment employing an entangled atom-light state.
In 1935 Erwin Schrödinger formulated a thought experiment designed to capture the paradoxical nature of quantum physics. The crucial element of this gedanken...
Cellulose obtained from wood has amazing material properties. Empa researchers are now equipping the biodegradable material with additional functionalities to produce implants for cartilage diseases using 3D printing.
It all starts with an ear. Empa researcher Michael Hausmann removes the object shaped like a human ear from the 3D printer and explains:
The phenomenon of so-called superlubricity is known, but so far the explanation at the atomic level has been missing: for example, how does extremely low friction occur in bearings? Researchers from the Fraunhofer Institutes IWM and IWS jointly deciphered a universal mechanism of superlubricity for certain diamond-like carbon layers in combination with organic lubricants. Based on this knowledge, it is now possible to formulate design rules for supra lubricating layer-lubricant combinations. The results are presented in an article in Nature Communications, volume 10.
One of the most important prerequisites for sustainable and environmentally friendly mobility is minimizing friction. Research and industry have been dedicated...
16.01.2019 | Event News
14.01.2019 | Event News
12.12.2018 | Event News
18.01.2019 | Materials Sciences
18.01.2019 | Life Sciences
18.01.2019 | Health and Medicine