Critical Contact Angle to Induce Capillary Rise of Polymers in Nanopores Does Not Depend on Chain Length

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 (θc) 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, θc 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 θc depends strongly on the size of statistical segments rather than N, which we confirm by performing MD simulations of infiltration with semiflexible polymers. These results could provide guidelines in manufacturing polymer nanostructures and nanocomposites using capillary rise infiltration.