  Carefully tuned composite materials can have properties wholly unlike their
separate constituents. We review the development of one example:
colloid-stabilized emulsions with bicontinuous liquid domains. These
non-equilibrium structures resemble the sponge mesophase of surfactants;
however, in the colloid-stabilized case the interface separating the liquid
domains is itself semi-solid. The arrangement of domains is created by
arresting liquid-liquid phase separation via spinodal decomposition. Dispersed
colloids exhibiting partial wettability become trapped on the newly created
interface and jam together as the domains coarsen. Similar structures have been
created in polymer blends stabilized using either interfacial nanoparticles or
clay platelets. Here it has been possible to create the domain arrangement
either by phase separation or by direct mixing of the melt. The low
molecular-weight liquid and polymer based structures have been developed
independently and much can be learnt by comparing the two.
