Phase behavior of symmetric disk-coil macromolecules with stacking interactions.

We investigate using Monte Carlo simulations in the NPT ensemble the self-assembly of disk-coil macromolecules with stacking interactions. The disk-coil molecules are composed of a planar disk that is covalently bonded to a single coil. In addition to commonly used amphiphilic interactions between the disk and coil portion of the molecules, we employ an attractive interaction between central monomers of the disks, which mimics stacking interactions. This additional force induces a preferential axial packing. The phase diagram of this system is complex and depends crucially on the stacking interactions. In particular, we find a variety of new phases that include for this system an ordered lamellar, ordered perforated lamellar, cylinder and ordered cylinder phases in addition to the disordered, lamellar, perforated lamellar, and crystal phases observed previously [Y. Kim and A. Alexander-Katz, J. Chem. Phys. 132, 174901 (2010)]. The ordered phases show strong tendency of parallel packing of disks. Among them, the ordered cylinder phase exhibits super-aligned structures which could have uses in many organic optoelectronic applications.