ceramic beads having a bimodal pore distribution are prepared by a process involving a ) formation of a ceramic particle slurry , b ) adding a foamable prepolymer to the slurry to form a mixture , c ) dispersing the mixture as beads in a second liquid , d ) polymerizing and foaming the prepolymer , e ) recovering the beads and firing them to remove the polymer and bond the ceramic particles . the beads can optionally be joined by sintering . beads with a monodal pore distribution can be made by using a nonfoaming prepolymer .