Organic power cable for electronic components
Liquid and solid – most people are unaware that there can be states in between. Liquid crystals are representative of one such state. While the molecules in liquids swim around at random, neighboring molecules in liquid crystals are aligned as in regular crystal grids, but the material is still liquid.
Liquid crystals are thus an example of an intermediate state that is neither really solid nor really liquid. They flow like a liquid, and yet their molecules are grouped in small, regularly ordered units. A particular application of liquid crystals is optical imaging technology as in the screens of televisions, smartphones, and calculators. All LCD – or liquid crystal display – devices use these molecules.
Researchers at the Institute of Organic Chemistry at Johannes Gutenberg University Mainz (JGU) have synthesized novel liquid crystals in a project sponsored by the German Research Foundation (DFG). "If you slowly cool our liquid crystalline materials, the molecules align in a self-assembly process to form columns," explained Professor Heiner Detert of JGU.
"We can imagine these columns like piles of beer mats stacked one on top of the other. But the special thing is that these columns conduct electrical energy along their whole length." The materials can thus serve as organic, liquid crystalline "power cables" and provide targeted electricity transmission in electronic components.
While most materials conduct positive charges carried by holes, the new molecules actually conduct electrons. An additional advantage of a liquid crystalline power cable is that if it ruptures, any such rupture will heal entirely by itself.
The researchers have identified a particularly interesting effect exhibited by their synthesized molecules: If a single molecule is stimulated by exposure to UV light, it will glow in response. If the concentration of the molecule increases, this effect disappears only to reappear again when the concentration continues to increase. If the molecules are suspended in a solvent or arranged on a film, they will fluoresce in various colors when irradiated with UV light.
Detert and his team together with Professor Matthias Lehmann of the Julius-Maximilians-Universität Würzburg recently published their results in Chemistry – A European Journal. Experts classified the research results as exceptionally significant and the journal editors selected the article as a Hot Paper. The lead author, Natalie Tober, is supported by a scholarship awarded by the Carl Zeiss Foundation.
The structural formula of liquid crystals superimposed on an image of the liquid crystal phase prepared using a polarized light microscope together with examples of the fluorescence exhibited by liquid crystals in various solvents (bottom right)
Ill./©: Natalie Tober, JGU
Professor Dr. Heiner Detert
Institute of Organic Chemistry
Johannes Gutenberg University Mainz
55099 Mainz, GERMANY
phone +49 6131 39-24189
fax +49 6131 39-25338
https://www.blogs.uni-mainz.de/fb09ak-detert/ [in German]
N. Tober et al., Synthesis, Thermal, and Optical Properties of Tris(5‐aryl‐1,3,4‐oxadiazol‐2‐yl)‐1,3,5‐triazines, New Star‐shaped Fluorescent Discotic Liquid Crystals, Chemistry – A European Journal, 19. August 2019
Petra Giegerich | idw - Informationsdienst Wissenschaft
Mobile measuring instruments: Caught in flight
07.07.2020 | Empa - Eidgenössische Materialprüfungs- und Forschungsanstalt
PCB-embedded GaN-on-Si half bridge circuits for modular use
06.07.2020 | Fraunhofer-Institut für Angewandte Festkörperphysik IAF
Kiel physics team observed extremely fast electronic changes in real time in a special material class
In physics, they are currently the subject of intensive research; in electronics, they could enable completely new functions. So-called topological materials...
Solar cells based on perovskite compounds could soon make electricity generation from sunlight even more efficient and cheaper. The laboratory efficiency of these perovskite solar cells already exceeds that of the well-known silicon solar cells. An international team led by Stefan Weber from the Max Planck Institute for Polymer Research (MPI-P) in Mainz has found microscopic structures in perovskite crystals that can guide the charge transport in the solar cell. Clever alignment of these "electron highways" could make perovskite solar cells even more powerful.
Solar cells convert sunlight into electricity. During this process, the electrons of the material inside the cell absorb the energy of the light....
Empa researchers have succeeded in applying aerogels to microelectronics: Aerogels based on cellulose nanofibers can effectively shield electromagnetic radiation over a wide frequency range – and they are unrivalled in terms of weight.
Electric motors and electronic devices generate electromagnetic fields that sometimes have to be shielded in order not to affect neighboring electronic...
A promising operating mode for the plasma of a future power plant has been developed at the ASDEX Upgrade fusion device at Max Planck Institute for Plasma...
Live event – July 1, 2020 - 11:00 to 11:45 (CET)
"Automation in Aerospace Industry @ Fraunhofer IFAM"
The Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM l Stade is presenting its forward-looking R&D portfolio for the first time at...
07.07.2020 | Event News
02.07.2020 | Event News
19.05.2020 | Event News
08.07.2020 | Materials Sciences
08.07.2020 | Health and Medicine
08.07.2020 | Physics and Astronomy