BAVARIAN RESEARCH ASSOCIATION FOR CARBON-BASED MATERIALS
III. 1 Nanoporous high temperature materials synthesized via a sol-gel process
The objective of the project is the synthesis of nanoporous carbon and silicon carbide aerogels for applications as high temperature materials in different fields.
The advantage of applying sol-gel synthesis instead of common approaches is the fact that the pores within the material can be adjusted between a few nanometers and a micron. The resulting carbon aerogels are expected to be – with respect to their thermal insulation properties - superior to conventional carbon based insulation materials with pore sizes in the order of 100 microns; this is due to the fact that at ambient gas pressure the gaseous contribution to the total thermal conductivity of a porous insulation material is effectively suppressed as soon as the pore size within the material drops below about 100 nm, i.e. the mean free paths of the gas molecules.
Since carbon starts burning at elevated temperatures in the presence of oxygen, applications that involve oxygen require the conversion of the carbon backbone of the aerogel into oxidation resistant silicon carbide. For the synthesis of silicon carbide aerogels different approaches will be tested within the framework of this project.
Large surface fibre reinforced carbon aerogels compounds have been already successfully synthesized for applications as electrodes in supercaps and fuel cells. The synthesis of carbon aerogel panels for prototypes therefore can performed based on the established know-how.