At DESY's X-ray source PETRA III, scientists have followed the growth of tiny wires of gallium arsenide live. Their observations reveal exact details of the growth process responsible for the evolving shape and crystal structure of the crystalline nanowires. The findings also provide new ap ... more
Nanoparticles digging the world’s smallest tunnels
The world’s smallest tunnels have a width of a few nanometers only. Researchers from Karlsruhe Institute of Technology (KIT) and Rice University, USA, have dug such tunnels into graphite samples. This will allow structuring of the interior of materials through self-organization in the nanometer range and tailoring of nanoporous graphite for applications in medicine and battery technology. Results are now presented in Nature Communications.
The tunnels are manufactured applying nickel nanoparticles to graphite which then is heated in the presence of hydrogen gas. The surface of the metal particles, that measure a few nanometers only, serves as a catalyst removing the carbon atoms of the graphite and converting them by means of hydrogen into the gas methane. Through capillary forces, the nickel particle is drawn into the “hole” that forms and bores through the material. The size of the tunnels obtained in the experiments was in the range of 1 to 50 nanometers, which about corresponds to one thousandth of the diameter of a human hair.
To furnish proof of the real existence of these graphite tunnels, the researchers have made use of scanning electron and scanning tunneling microscopy. “Microscopes, in fact, image only the upper layers of the sample,” the principal authors of the study, Maya Lukas and Velimir Meded from KIT’s Institute of Nanotechnology, explain. “The tunnels below these upper layers, however, leave atomic structures on the surface whose courses can be traced and which can be assigned to the nanotunnels by means of the very detailed scanning tunneling microscopy images and based on computerized simulations.” In addition, the depth of the tunnels was determined precisely by means of a series of images taken by a scanning electron microscope from different perspectives.
Porous graphite is used, for example, in the electrodes of lithium ion batteries. The charge time could be reduced using materials with appropriate pore sizes. In medicine, porous graphite could serve as a carrier of drugs to be released over longer periods of time. Replacing graphite by nonconductive materials, e.g. boron nitride, with atomic structures similar to that of graphite, the tunnels could serve as basic structures for nanoelectronic components such as novel sensors or solar cells.
- Rice University
- Karlsruher Institut…
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a phenomenon similar to an effect observed in circular galleries, such as in some cathedrals or museums, where sound waves travel across t ... more
Optical microscopy is applied widely in the life sciences sector. Among others, it is used to minimally invasively examine living cells. Resolution of conventional light microscopy, however, is limited to half the wavelength of light, i.e. about 200 nm, such that finest cellular structures ... more
Rice University researchers have added a new dimension to their breakthrough technique that expands the capabilities of standard laboratory microscopes. Two years ago, the Rice lab of chemist Christy Landes introduced super temporal resolution microscopy, a technique that allowed researcher ... more
Rice University researchers have discovered a fundamentally different form of light-matter interaction in their experiments with gold nanoparticles. They weren't looking for it, but students in the lab of Rice chemist Stephan Link found that exciting the microscopic particles just right pro ... more
Rice University nanoscientists have demonstrated a method for loading iron inside nanoparticles to create MRI contrast agents that outperform gadolinium chelates, the mainstay contrast agent that is facing increased scrutiny due to potential safety concerns. "The possibility of eliminating ... more
- 1Virtual screening for active substances against the coronavirus
- 2analytica 2020 is postponed
- 3FDA Provides Emergency Use Authorization to PerkinElmer for COVID-19 Testing
- 4Roche’s cobas SARS-CoV-2 Test to detect novel coronavirus receives FDA Emergency Use Authorization
- 5The digital laboratory live and tangible
- 6Smartphone lab finds coronavirus in saliva
- 7Thermo Fisher Scientific to Acquire QIAGEN
- 8Pool testing of SARS-CoV-02 samples increases worldwide test capacities many times over
- 9Abbott Receives FDA Emergency Use Authorization and Launches Test to Detect Novel Coronavirus
- 10Bosch develops rapid test for COVID-19