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 History in 3-D If you don't have the time to travel to Florence, you can still see Michelangelo's statue of David on the Internet, revolving in true-to-life 3D around its own axis. Materials scientists find better model for glass creation Harvard materials scientists have come up with what they believe is a new way to model the formation of glasses, a type of amorphous solid that includes common window glass. Study sheds light on evolution of human complexity A painstaking analysis of thousands of genes and the proteins they encode shows that human beings are biologically complex, at least in part, because of the way humans evolved to cope with redundancies arising from duplicate genes. Hydrogen Peroxide's Link to Living Cells If a circadian rhythm is like an orchestra - the united expression of the rhythms of millions of cells - a common chemical may serve as the conductor, or at least as the baton. A look at public policies and motorcycle safety in the US One of the joys of riding a motorcycle is the freedom that comes with that form of travel. However the absence of physical barriers to protect riders puts motorcyclists at a higher risk of injury than other motorists. Muscle weakness a common side effect of long stays in intensive care units After decades of focusing on the management of respiratory failure, circulatory shock and severe infections that lead to extended stays in hospital intensive care units, critical care researchers are increasingly turning attention to what they believe is a treatable complication developed by many who spend days or weeks confined to an ICU bed: debilitating muscle weakness that can linger long after hospital discharge. Trembling hands and molecular handshakes Fragile X tremor/ataxia syndrome (FXTAS) is a recently recognized condition, which is actually one of the most prevalent heritable neurodegenerative diseases. Berkeley researchers create first hyperlens for sound waves Ultrasound and underwater sonar devices could "see" a big improvement thanks to development of the world's first acoustic hyperlens. Created by researchers with the U.S. Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab), the acoustic hyperlens provides an eightfold boost in the magnification power of sound-based imaging technologies. Scientists of the UGR obtain a bioinsecticide to control the Mediterranean fruit fly UGR News The Mediterranean fruit fly, Ceratitis capitata, is a world plague which represents one of the most serious problems for agriculture. However, the control methods currently present in the market for this plague are ineffective. Manipulating Brain Inflammation May Help Clear Brain of Amyloid Plaques, Mayo Clinic Researchers Say In a surprising reversal of long-standing scientific belief, researchers at the Mayo Clinic campus in Florida have discovered that inflammation in the brain is not the trigger that leads to buildup of amyloid deposits and development of Alzheimer's disease. More Research Group Current Events and Research Group News Articles |
|||||||||||||||||||||
|
|||||||||||||||||||||
|
|||||||||||||||||||||