Chain conformations in adsorbed layer during polymer capillary imbibition

Abstract

We conducted molecular dynamics simulations to investigate chain conformations in adsorbed layers during polymer capillary imbibition. While the imbibition length adheres to the classical Lucas-Washburn equation, a notable deviation in mobile bead density emerges under strong confinement, consistent with \emph{in situ} dielectric spectroscopy experiments. The proportion of loop structures within adsorbed layers progressively increases during capillary infiltration, attributed to the relaxation of initially stretched chains toward equilibrium configurations. Furthermore, systematic analysis revealed that chain relaxation dynamics exhibit length-dependent retardation, especially under high confinement. The characteristic desorption time demonstrates chain-length dependence in quantitative agreement with scaling predictions.