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nanotimes News in Brief

Physicists at the University of Luxembourg have developed a new method to improve the electrical conductivity of polymeric composites. Polymeric composites consist of two or more materials and are used for example to shield off electrostatics in airplanes. By introducing additives into polymeric composites, favourable properties can be achieved. For instance, they develop favourable electrical properties when reinforced with carbon nanotubes. Such composites are used to make flat-panel dis- plays and solar cells more efficient.

The researchers in Luxembourg, in cooperation with scientists from the Netherlands, have studied the electrical percolation of carbon nanotubes in a po- lymer matrix and shown the percolation threshold - the point at which the polymer composite becomes conductive – can be considerably lowered if small quantities of a conductive polymer latex are added. The simulations were done in Luxembourg, while the experiments took place at Eindhoven University.

“In this project, the idea is to use as little as possible carbon nanotubes and still benefit from their fa- vourable properties”, says the project leader at the University of Luxembourg, Prof. Tania Schilling, “we have discovered that, by adding a second compo- nent, we could make use of the resulting interac- tions to reach our goal.”

By mixing finely dispersed particles, so-called colloidal particles, of differing shapes and sizes in the medium, system-spanning networks form: the prerequisite for electrically conductive composites.

11-04 :: April/May 2011

Percolating network of rods and sphere, © University of Luxembourg

Andriy V. Kyrylyuk, Marie Claire Hermant, Tanja Schilling, Bert Klumperman, Cor E. Koning, Paul van der Schoot: Controlling electrical percolation in multicomponent car- bon nanotube dispersions, In: Nature Nanotechnology AOP, April 10, 2011, DOI:10.1038/nnano.2011.40: http://dx.doi.org/10.1038/nnano.2011.40

German FHG Researchers have now developed sensors capable of expanding, in extreme cases, to twice their original length and so supple as to go virtually unnoticed when sewn into clothing. These systems can be seen at the Sensor+Test trade fair in Nuremberg from June 7 to 9, 2011 (Hall 12, Booth