Effect of channel flexibility on confined water transport

Abstract

Water transport through confined channels is a significant fundamental process in various scientific fields. However, the effect of channel flexibility, particularly on water transport through channels of a certain thickness common in experiments, has not been elucidated. Using non-equilibrium molecular dynamics, we found that flexible channels show lower entrance/exit resistances but higher interior resistances than rigid channels. Therefore, water transport through flexible non-atomically thick channels is slower than through rigid non-atomically thick counterparts, which is completely opposite to currently reported observations in atomically thick channels. Molecular analyses indicate that conical effects accelerate water transport through flexible atomically thick channel, but higher pore wall frictions inside channels hinder water transport through non-atomically thick channels. This work reveals the neglected effect of channel flexibility on water transport, which not only deepens the understanding of transport mechanisms, but also guides the experimental selection of rigid channels for water transport.