Paper electrified by copper particlesMarch 16, 2009The Polymer Chemistry Research Group at the University of Helsinki, Finland, has succeeded in producing nano-sized metallic copper particles. 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. University of Helsinki |
|||||||||||||||||||||
| Related Research Group Current Events and Research Group News Articles Visual assistance for cosmic blind spots A bit of imagination on the part of a measuring instrument wouldn't be a bad thing. It could help to add data from areas where the instrument is unable to measure. New discovery about the formation of new brain cells The generation of new nerve cells in the brain is regulated by a peptide known as C3a, which directly affects the stem cells' maturation into nerve cells and is also important for the migration of new nerve cells through the brain tissue, reveals new research from the Sahlgrenska Academy published in the journal Stem Cells. Milestone biodefense publication by Elsevier journal Vaccine Last week during the 'Vaccines for Biothreats and Emerging and Neglected Diseases Symposium' in Galveston TX, USA, the Elsevier journal Vaccine released a supplement dedicated to vaccines for biodefense. Berkeley Researchers Take the Lead Out of Piezoelectrics There is good news for the global effort to reduce the amount of lead in the environment and for the growing array of technologies that rely upon the piezoelectric effect. NIST demonstrates 'universal' programmable quantum processor Physicists at the National Institute of Standards and Technology (NIST) have demonstrated the first "universal" programmable quantum information processor able to run any program allowed by quantum mechanics-the rules governing the submicroscopic world-using two quantum bits (qubits) of information. Continuous chest compression-CPR improved cardiac arrest survival in Arizona The chance of surviving a cardiac arrest outside a hospital was found to be twice as high when bystanders performed continuous chest compressions without mouth-to-mouth breathing than when bystanders performed standard CPR. New explanation for nature's hardiest life form Got food poisoning? The cause might be bacterial spores, en extremely hardy survival form of bacteria, a nightmare for health care and the food industry and an enigma for scientists. Surgeon 'gluing' the breastbone together after open-heart surgery An innovative method is being used to repair the breastbone after it is intentionally broken to provide access to the heart during open-heart surgery. The technique uses a state-of-the-art adhesive that rapidly bonds to bone and accelerates the recovery process. Nanotech in Space: Rensselaer Experiment To Weather the Trials of Orbit Novel nanomaterials developed at Rensselaer Polytechnic Institute are scheduled to blast off into orbit on November 16 aboard Space Shuttle Atlantis. CU-Boulder Butterfly Payload to Launch Nov. 16 on Space Shuttle When NASA's space shuttle Atlantis launches for the International Space Station on Nov. 16 it will carry a University of Colorado at Boulder butterfly experiment that will be monitored by thousands of K-12 students across the nation. More Research Group Current Events and Research Group News Articles |
|||||||||||||||||||||
|
|||||||||||||||||||||
|
|||||||||||||||||||||