When the size of particles is reduced to a nano-scale (one nanometre being one billionth of a metre), the properties of the material undergo substantial changes. Unlike in bulk materials, in nanoparticles the number of surface atoms is considerably greater than the number of atoms inside the material, which, among other things, makes the melting temperature of nanomaterials very low.
With suitable heat treatment (sintering), the particles manufactured by the research group can be made to form electricity-conducting layers and patterns on paper.
The research result is interesting in that polymer-protected metal particles can also be used in various electronics applications: various kinds of intelligent patterns can be printed on paper that, in the future, may replace components such as electronics boards.
The findings were recently reported in an international journal.
The purpose of the research was to test the ability of polymeric and small-molecule compounds that contain amine groups to protect copper nanoparticles during their manufacturing stage. The particles were manufactured with either poly(ethylene imine) (PEI) or tetraethylenepentamine (TEPA) used as protecting compounds.
The average size of the particles at room temperature was 8.5 nm (with PEI as the protecting agent) or 19.4 nm (with TEPA as the protecting agent). Slightly oxidised at their surface, the particles were sintered to the paper surface, and the electrical conductivity of the layer thus formed was measured.
Particles manufactured using PEI released the protective agent during sintering at relatively low temperatures (150-200 °C). At these temperatures, the size of the particles increased rapidly. The electrical conductivity of the sintered particles was good, which makes them promising materials for use in electronics printed on paper.
At the University of Helsinki, a research group led by Professor Heikki Tenhu synthesises the so-called intelligent polymers and studies controlled polymerisation reactions. Polymers are large-molecule compounds that, as functional materials, change their properties according to the changing ambient conditions.
Heikki Tenhu | EurekAlert!
Further reports about: > PEI > Polymere > TEPA > bulk materials > copper > copper particles > electrical conductivity > electronics applications > heat treatment > nano-scale > nano-sized metallic copper particles > nanometre > poly ethylene imine > sintering > surface atoms > tetraethylenepentamine
Sleep as energy saving mode
21.11.2017 | Universitätsspital Bern
20.11.2017 | Washington University in St. Louis
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...
Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.
During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....
The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.
Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...
Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
20.11.2017 | Earth Sciences
20.11.2017 | Earth Sciences
20.11.2017 | Life Sciences