FIGURE 2. Monomer ordering in supramolecular co-polymers.

These co-polymers form from mixtures of different kinds of self-assembling monomer. The ordering of the monomers depends on the binding modes of their hydrogen-bonding groups. a, If the different kinds of group on each monomer form complementary bonds (only to each other), an alternating sequence of monomer types forms. b–d, If the groups are self-complementary (they bind to their own kind) but are also able to form hydrogen bonds to other kinds of group, there are three different possibilities. b, Normally, a random chain of monomers forms. c, Alternatively, a chain assembles containing distinct blocks of one kind of monomer. This can happen when, for example, there are two self-complementary arrays AA and BB that can form a self-complementary AB interaction of much lower strength. d, If the monomers repel each other and don't mix, the polymer forms as a blend of chains that each contain one kind of monomer.