Nanoparticles and Nanocomposites

Porous ceramic used as water filter for bacteria. With the coated Y2O3 nanoparticles also viruses can be filtered electrostatically.

Nanomaterials – be they in the form of particles, wires or tubes – exhibit unique physical properties: electronic properties that are dominated by quantum effects; higher mechanical strength and, most obviously, a very high specific surface area. Empa has extensive competences and excellent facilities for the synthesis of nanoparticles, nanocrystals, nanofibers and carbon nanotubes in lab- and pilot-scale batches. By flame spray synthesis (FSS) we are producing oxide nanoparticles such as silica, titania, zirconia, perovskites, various types of mixed oxides and composite particles with well-defined composition and morphology. Non-oxide nanoparticles like carbides and nitrides are produced out of solid precursors using the inductively coupled vacuum plasma process (ICP). With such an ICP facility we also produce silicon nanoparticles in larger quantities. Nanofibers of various compositions can be produced by electrospinning, nearly monodisperse metal and semiconductor nanocrystals with diameters between 3 – 20 nm by colloidal chemistry approaches.

With our pilot plants we produce nanomaterials in relevant quantities, which allows us the development of novel composites and coatings. Tailored oxide nanoparticles in polymer composites lead to improved mechanical properties, scratch resistance and super-hydrophilicity as well as easy-to-clean and anti-bacterial properties. The functional and structural performance of metallic and ceramic materials, including thermal and electrical conductivity, hardness, wear resistance and elevated temperature stability, can be considerably enhanced by the integration of ultra-fine nano-sized structures. Silicon nanoparticles or tin nanocrystals are excellent candidates to replace graphite as anode material in Li-ion batteries. Composites of these materials show gravimetric capacities that are more than 3-times higher than graphite and – equally important – an excellent cycle stability.