Ejection dynamics of spherically confined active polymers through a small pore

Abstract

Using Brownian dynamics simulations, we study the ejection dynamics of spherically confined active polymers through a small pore. Although the active force can provide a driving force other than the entropy drive, it also causes the collapse of the active polymer, which in turn reduces the entropy drive. Thus, our simulation results confirm that the active polymer's ejection process can be divided into three stages. In the first stage, the influence of the active force is small, and the ejection is mainly an entropy-driven process. In the second stage, the ejection time satisfies the scaling relationship with the chain length, and the value of obtained scaling exponent is less than 1.0, indicating that the active force accelerates the ejection process. In the third stage, the scaling exponent is maintained at about 1.0, where the active force dominates the ejection process, and the ejection time is inversely proportional to the Péclet number. Furthermore, we find that the ejection velocity of the trailing particles has significant differences at different stages and is the core factor of the ejection mechanism at different stages. Our work helps us understand this non-equilibrium dynamic process and enhances our prediction of the relevant physiological phenomena.