Berlin 2008 – wissenschaftliches Programm

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DS: Fachverband Dünne Schichten

DS 29: Nanoengineered Thin Films

DS 29.5: Vortrag

Donnerstag, 28. Februar 2008, 19:00–19:15, H 2013

Physico-chemical Properties of Metal-Polymer Nanocomposite Films near the Percolation Threshold — •Vladimir Zaporojtchenko, Haile Takele, Christian Hanisch, Amit Kulkarni, Thomas Strunskus, and Franz Faupel — Chair for Multicomponent Materials, Technical Faculty of the CAU Kiel, Kaiserstrasse 2, D-24143 Kiel, Germany

The present talk reviews properties of metal-polymer nanocomposite films (MPNF) with high volume fractions of metal nanoparticles close to the percolation threshold. In this regime, the DC electrical conductivity and the permittivity are extremely sensitive to the nanoparticle concentration and separation. The morphology of the nanocomposites (particle size and distribution) prepared by PVD methods depends on the properties of the selected polymer and metal as well as on the preparation parameters, i.e. deposition rate and substrate temperature. As a consequence, a percolation threshold in the conductivity was observed at different critical metal concentrations ranging from 15 to 40 vol. %. It is demonstrated also that the optical, electrical and chemical properties may be varied widely close to percolation. Thus the index of refraction can be tuned over a wide range and surface plasmons, occurring for noble metals in the visible range, can be shifted to the infrared region. MPNF chemical sensors are based on the swelling of the polymer matix in the presence of organic vapors. Moreover, new polymer-metal composites with photochromic properties will be presented.