(725g) Creation and Characterization of Magnesium Oxide Macroporous Ceramics

Highly porous and permeable magnesium oxide (MgO) ceramic foams are useful to many applications ranging from filtering molten metal alloys to providing support structures for catalysts.  We examine several methods to create a sheet of MgO macroporous ceramic material via tape casting.  These methods include the approach pioneered by Akartuna et al. (2008) in which an oil/water emulsion is stabilized by surface-modified metal oxide particles at the droplet interfaces.  Upon drying,  a scaffold of the self-assembled particles is strong enough to be removed from the substrate material and sintered. We find that this method can be used with MgO particles surface modified by short amphiphillic molecules.  This approach is compared with two more traditional methods to induce structure into a green ceramic : 1) creation of an MgO ceramic slip with added pore formers, and 2) sponge impregnation of a reticulated foam with the MgO slip.  With each method the green and sintered materials are hardness tested and results compared for several densities of the final ceramics.  Optical and SEM images of the materials will also be shown.

Sandia National Laboratories is a multi-program laboratory managed and 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.