Diblock copolymers—made up of a chain of monomer A bound to a chain of monomer B, as shown in figure 1a—are of great theoretical and practical interest. When the A and B monomers are sufficiently immiscible, they can segregate into self-assembled periodic nanostructures such as alternating layers or hexagonally ordered rods. The morphology of those two-phase structures depends on the phase immiscibility, the relative lengths of the A and B chains, and other factors. Choosing the A and B phases with complementary properties enables a variety of applications. (See the article by Frank Bates and Glenn Fredrickson, Physics Today, February 1999, page 32.)
For example, to make a solid-state electrolyte for a battery or fuel cell, one can optimize the A phase for ionic conductivity, with negative ions bound to the polymer chains balanced by unbound positive ions, and the B phase for mechanical stability. Numerous experiments,...
