Abstract
Currently, the theories of single polymer confi ned in the micro/nano channel are classfi ed to fi ve regime, from weak confi nement to strong confi nement: bulk, de Gennes, extended de Gennes, transition and Odijk. The behavior of every regime have been repeatedly verifi ed by many computer simulation, including the static and dynamic properties, but most of these results are all based on the neutral chain model, and ignore the interaction with ions which include counterion, cation and anion. Although the assumption of neutral chain model is useful to simplify the complex structure of polymer, this situation is quite di fferent to the real experiment in which researchers are more interested in understanding confi ned biomolecules, such as DNA or protein, in micro/nano-scale devices for biological application. These biomolecules are not only ionized, but also survive in the bu er which contain many kind of ion. Therefore, to understand the more realistic system, the simulation model should employ charged chains and ions. Including ions accounts for important electrostatic screening and ion condensation e ffects, which may lead to complex phenomenon. In this work, we perform molecular dynamics simulations to investigate charged polymers confi ned in a cylindrical channel with diameter D. The coarse-grained method is used to model polyelectrolyte chains and monovalent ions in the solutions, and study the con figuration of polymer from the interactions between ions, polymers and the channel wall.