By coating supports with an alumina sol-gel, which is then immersed in liquid nitrogen, freeze-dried and subsequently calcined, it has been confirmed (with scanning electron microscopy) that leaf-like structures with nano-thin walls can be formed from alumina. This work confirms that similar structures can be formed to the KK leaves described in the literature. By exploring different preparation techniques, it is confirmed that to form such leaf-like structures, the steps consisting of: immersion in liquid nitrogen, freeze-drying and calcination, are all essential.Using these techniques, coating methods with a silica sol-gel are also explored, and when cordierite ceramic monoliths were coated, some exciting structures consisting of plates, leaves and tunnels with nano-thin walls were formed which could have commercial applications.Adopting these novel coating procedures, 3.2 mm wire-mesh Dixon rings (used as a packing in a gas scrubbing column) were also successfully coated with sol-gels made from alumina and also silica. These coated 3.2 mm rings were then impregnated with a carbonic anhydrase enzyme, to test if the presence of the enzyme (acting as a catalyst) could increase the overall rate of CO2 removal from a gaseous stream in a small gas scrubber. A very small improvement was observed but this requires further work to confirm its viability.
|Date of Award||5 Nov 2013|
|Supervisor||Stan Kolaczkowski (Supervisor) & Serpil Awdry (Supervisor)|