Method of coating a substrate with a particle stabilized foam

A method of coating a substrate with a foam, wherein the method comprises:

• (a) introducing a particle-stabilized, alumina-based foam into a substrate comprising a plurality of channels through open ends of the channels at a first end of the substrate;
• and
• (b) applying at least one member selected from the group consisting of (i) a vacuum to open ends of the channels at a second end of the substrate, wherein the vacuum draws the foam into the substrate through the open ends of the channels at the first end, and (ii) a pressure to the open ends of the channels at the first end of the substrate wherein the pressure pushes or blows the foam into the substrate through the open ends of the channels at the first end,
• wherein the substrate is constructed of a material containing at least one of silicon carbide, aluminium nitride, silicon nitride, aluminium titanate, cordierite, mullite, pollucite, a thermet, an Fe—Cr—Al alloy, a Ni—Cr—Al alloy, and a stainless-steel alloy;
• wherein the substrate is a honeycomb monolith substrate having a plurality of channels that extend longitudinally along the length of the substrate;
• and
• wherein the foam comprises a particulate material.