Abstract: The method of making a three-dimensional article includes heating a composition comprising a polymer and hollow ceramic microspheres, extruding the composition in molten form from an extrusion head to provide at least a portion of a first layer of the three-dimensional article, and extruding at least a second layer of the composition in molten form from the extrusion head onto at least the portion of the first layer to make at least a portion of the three-dimensional article. Three-dimensional articles are also described. A composition including a polymer and hollow ceramic microspheres is also described. The composition may be a filament. The polymer is at least one of a low-surface-energy polymer or polyolefin. The composition can be useful, for example, in melt extrusion additive manufacturing, for example, fused filament fabrication.

Abstract: A catalytic burner includes a porous diffuser member and a porous distributor member. At least one seal extends between the porous diffuser member and the porous distributor member thereby defining an oxidation chamber. Catalyst media particles for catalyzing an oxidation reaction of a fuel stream to produce heat and an exhaust stream is disposed within the oxidation chamber. The catalyst media particles comprise carrier particles. The carrier particles comprise refractory material, and at least some of the carrier particles have thereon an outer coating comprising an oxidation catalyst. The catalyst media particles have a void fraction of at least 0.6.