(9a) Highly Porous Ceramic Foams From Magnesium Oxide Stabilized Pickering Emulsions

Porous and permeable ceramic scaffolds are useful to many applications ranging from catalyst supports, filtering molten metal alloy, and high temperature insulation.  Ceramic foams with porosities over 90% can be created by drying and sintering particle stabilized oil-water emulsions.  This technique is optimized for the creation of magnesium oxide porous scaffolds.  Processing parameters such as emulsion mixing speed, particle concentration, and drying time are related to final properties such as porosity and mechanical strength. Electrochemical impedance spectroscopy is used to measure sample permeability, and scanning electron microscopy is used to image sample microstructure.  The impacts of the hydroxylation of magnesium oxide to brucite on the foam performance will also be discussed.  Finally, the quality of the ceramic foams will be compared to porous ceramics produced by other methods: 1) blade coating of an MgO slip, which is then laser-drilled with a set array of holes, 2) blade coating of a slip with added pore formers, and 3) sponge impregnation of a reticulated foam with a slip in a replication process. 

This research is supported by the Laboratory Directed Research and Development program at Sandia National Laboratories. Sandia National Laboratories is a multi-program laboratory operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000.