Paper SE+NS+TF-ThA12
Silicone Nanofilaments as a Novel Carrier Material for Catalysts

Thursday, October 31, 2013, 5:40 pm, Room 203 C

Immobilization of molecular and nanoparticulate catalysts on carrier materials is crucial to facilitate their handling and recycling as well as to minimize environmental and health risks. While ceramic and oxidic carrier materials provide stability under rough working conditions, engineering possibilities and applications are restricted to extruded or pressed shapes. We introduce silicone nanofilaments (SNFs) as a promising alternative because they can be grown as a thin film on a variety of substrates such as glass, metals and polymers of different composition and shape. A surface bound carpet of SNFs is formed which induces a high surface roughness and conveys the unique physico-chemical properties of a silicone polymer to the coated surface. The procedure uses easily available silane precursors and proceeds via either vapor deposition or solvent based routes. The shape and size of the single filaments within the carpet is tunable and they typically show a high aspect ratio with diameters from 50 to 100 nm and lengths on the micrometer scale. To exploit SNFs as a carrier material we applied deposition-precipitation (DP) to finely disperse titania nanoparticles (TiO₂-NPs) along the filaments. The thus obtained easily recyclable composite of SNFs and TiO₂-NPs showed photocatalytic performance in the degradation of methylene blue which was superior to TiO₂-NPs on a flat reference. While DP can in principle be used to deposit a variety of powerful catalysts, we also investigated physical vapor deposition as a complementary approach. Here, SNFs were uniformly coated with platinum metal via sputter coating. In the hydrogenation of 4-Nitrophenol we proved that this composite material represents a recyclable and easy to handle alternative to nanoparticle based systems.