Two-dimensional (2D) crystals have unique properties that may be useful for a range of applications. Consequently there is high interest in the mechanism for producing 2D crystals by exfoliating materials with layered structures.
Now researchers in Japan have reported an unusual phenomenon that layered materials undergo drastic swelling without breaking into separate 2D crystal layers. “The findings demonstrate important implications for and chemical insight into the exfoliating process,” say the researchers.
Certain ions or solvents can infiltrate materials with layered structures. This ‘intercalation’ sometimes causes excessive swelling and ultimately exfoliation into separate layers. The process of exfoliation has been studied in a number of materials including graphite, oxides, and hydroxides among others. In all these materials, exfoliation into separate layers occurs after swelling of less than several nanometres, which raises difficulties in analysis of the swelling stage, and hence the exfoliation mechanism as a whole.
Now Takayoshi Sasaki and colleagues at the International Center for Materials Nanoarchitectonics at the National Institute for Materials Science and the Fukuoka Institute of Technology in Japan have realized up to 100-fold swelling of layered protonic oxides, otherwise known as solid acids, without exfoliation, by exposure to an aqueous amine solution. Adding HCl reduced them to their original size. Notably, n the process more than3000 atomic sheets, which comprise of the starting crystal, instantly move apart and reassemble like shuffled poker cardsUnlike previously reported swelling or exfoliation, which swell far less before exfoliation, the swollen structures produced by exposure to the amine solution remained stable even when shaken. The researchers explain the stability using molecular dynamics calculations. “Unlike the random H2O in the previously reported swollen phases that could be easily exfoliated, long-range structuring of the H2O molecules in the highly swollen structure was confirmed using first-principle calculations.” The observations also provide important insights into the physics of these systems.
2. Department of Life, Environment and Materials Science, Fukuoka Institute of Technology, Wajiro-Higashi, Higashi-ku, Fukuoka 811-0295, Japan
Move over, Superman! NIST method sees through concrete to detect early-stage corrosion
27.04.2017 | National Institute of Standards and Technology (NIST)
Control of molecular motion by metal-plated 3-D printed plastic pieces
27.04.2017 | Ecole Polytechnique Fédérale de Lausanne
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
28.04.2017 | Event News
20.04.2017 | Event News
18.04.2017 | Event News
28.04.2017 | Medical Engineering
28.04.2017 | Earth Sciences
28.04.2017 | Life Sciences