CNT coatings


Al2O3 support tubes before and after carbon deposition on inner tube surfaces.
SEM image.
Single gas measurement

Carbon nanotubes (CNTs) are allotropes of carbon with a cylindrical nanostructure and outstanding properties. Due to their high specific surface area and resultingly high aspect ratio as well as extremely high thermal conductivity and mechanical stability, they are predestined for use as membrane materials for gas separation, catalysis, and energy storage applications.

The work of the "Carbon-Based Membranes" group is concerned with the deposition of CNTs on asymmetric ceramic substrates made up of ceramic layers of differing porosity and thickness. Metal particles are deposited on the substrates as catalysts, on which the precursor gas is converted to CNTs in a subsequent chemical vapor deposition (CVD) step. Depending on the substrate material, the catalyst, and the CVD process parameters used, gas separation, catalytically active, or electrically conductive CNT layers can be produced.

Carbon nanotubes hold great potential for adsorption-selective separation of mixtures of gases with similar molecular sizes (e.g. paraffin and olefin). With their cylindrical nanostructure and high internal surface area, CNTs are ideal materials for gas storage. The catalytic activity lends itself well to substance transformation with simultaneous substance separation.

Finally, the high electrical conductivity can be harnessed in battery applications (electrode materials).


Services offered


  • Preparation of CNT layers on tubular and flat ceramic substrates with different porosities
  • Optimization and modification of CNT layers for applications in membrane separation, gas storage, catalysis, and batteries
  • Combination of membrane separation and catalytic conversion (membrane reactor)
  • Customer-specific separation tests
  • Stability tests