Self-organization in solutions of stiff-chain amphiphilic macromolecules

Conformational properties of amphiphilic stiff-chain macromolecules in concentrated solutions in poor solvent have been studied via computer modeling. We have found that the conformational state of macromolecules in such systems depends on the macromolecular stiffness and on the way the solution has been prepared. Thus, if the concentration of globules increased from a very diluted solution, the globules remain stable, independent of the macromolecular stiffness, and do not aggregate even in concentrated solutions. On the other hand, if the solvent quality is gradually decreased in a solution with a concentration much larger than that of a semidilute solution, then relatively flexible chains form separate globules, whereas semirigid macromolecules tend to aggregate and form braid-like conformations. The results obtained agree with the published experimental data and can be used for directed synthesis of macromolecules modeling the behavior of biopolymers.