Bond Stiffness, not Chain Length, Dictates Polymer Infiltration into Nanopores

We study the effect of physical confinement on the capillary infiltration of polymers into cylindrical nanopores using molecular dynamics simulations. In particular, we probe whether the critical contact angle above which capillary rise infiltration ceases to occur changes for long chain polymers, possibly due to loss of conformation entropy induced by chain confinement. Surprisingly, the critical contact angle does not strongly depend on the length of polymer chains and stays constant for large N. A free energy model is developed to show that the critical angle for infiltration depends strongly on the size of statistical segments rather than the total chain length, which we confirm by performing MD simulations of infiltration with semi-flexible polymers. These results could provide guidelines in manufacturing polymer nanostructures and nanocomposites using capillary rise infiltration.