Minimal energy packings of weakly semiflexible polymers: Application to targeted self-assembly of nanostructures

Using exact enumeration, we characterize how structure, mechanical and thermodynamic stability of minimal energy packings of short ``sticky tangent sphere'' (SHS) polymer chains vary with angular interaction strength $k_b$ and equilibrium bond angle $\theta_0$. While flexible SHS polymers possess highly degenerate ground states (i.\ e.\ many differently ordered ``macrostates'' [1]), angular interactions dramatically break this degeneracy. The macrostate associated with the ground state semiflexible packing changes as $k_b$ and $\theta_0$ are varied. Further degeneracy breaking arises from angular interactions' influence on packing size, asymmetry, and vibrational entropy. The strength of these effects increases with chain length $N$. Our exact analysis provides design principles for self-assembly of polymers into a variety of structures that can be tuned by varying $N$, $k_b$ and $\theta_0$. \\[4pt] [1] R. S. Hoy and C. S. O'Hern, Phys. Rev. Lett. \textbf{105}, 068001 (2010).