Polymer Dynamics under Diamond Network Confinement

The dynamics and conformation of polymers under nanoconfinement have been actively studied over past few decades. Both simulation and experimental results have shown that properties of polymers are affected by confinements including changes in molecular mobility, changes to the local dynamics, and reduced inter-chain entanglements. The majority of these studies have focused on parallel confining surfaces and cylindrical pore confining geometries. How confinement geometries with multiple length scales such as porous networks impact polymers is yet to be fully explored. In our study, we construct a diamond network confining geometry with two characteristic length scales (strut diameter and distance between strut junctions) to mimic porous network confinement. Through MD simulations, we studied the effect of multi-scale diamond network confinement on diffusion and conformation of polymers whose chain length spans from unentangled to entangled in bulk simulations. Our early results show that as the distance between junctions increases, the diffusivity increases, and entanglement density decreases. We also analyze the chain relaxation based on Rouse modes and show separate, competing effects of the changes in the local friction near the wall and chain disentanglement.