Nanocubes could make polymer chemistry childs play
Chemists make the world’s smallest building blocks.
US researchers have made the world’s smallest building blocks. The nanocubes are just a millionth of a millimetre (a nanometre) across1. Stacked like bricks, they could make up a range of materials with useful properties such as light emission or electrical conduction.
Many chemists are currently trying to develop molecular-scale construction kits in which the individual components are single molecules to provide the polymers of the future. Conventional polymers are chainlike molecules. These entangle to form plastics ranging from soft polyethylene to hard polystyrene.
Richard Laine and colleagues at the University of Michigan in Ann Arbor want to replace chains with bricks. Their molecular units are silicon and oxygen atoms linked into a cube-shaped framework with a silicon at each corner.
The researchers connect the cubes by their corners - each corner silicon has a ’spare’ bond to which other chemical groups can be attached.
Similar materials have been prepared previously using corner linkers made from chainlike hydrocarbons. Like cubic octupi with eight arms, these are of limited practical value because they decompose quite easily when heated, and form messy glass-like solids instead of well-ordered crystals with the cubes stacked precisely.
Laine’s team address this problem by replacing the loose, chain-like linker arms with stiff, stubby arms: compact aromatic molecules derived from benzene. These should make the resulting materials more stable and rigid.
For example, the nanocubes make a curable resin that can withstand heating above 500 oC in air. And by appending different molecular groups to the short benzene-like arms, the researchers have made a material that conducts electricity, which might be used in polymer-based light-emitting diodes for display devices. A third kind of cubic molecule emits green light and could be useful in sensors and displays.
PHILIP BALL | © Nature News Service
Nanoparticle Exposure Can Awaken Dormant Viruses in the Lungs
16.01.2017 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt
Cholera bacteria infect more effectively with a simple twist of shape
13.01.2017 | Princeton University
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).
Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...
Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.
The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...
UMD, NOAA collaboration demonstrates suitability of in-orbit datasets for weather satellite calibration
"Traffic and weather, together on the hour!" blasts your local radio station, while your smartphone knows the weather halfway across the world. A network of...
10.01.2017 | Event News
09.01.2017 | Event News
05.01.2017 | Event News
17.01.2017 | Earth Sciences
17.01.2017 | Machine Engineering
17.01.2017 | Physics and Astronomy