# Small activity differences drive phase separation in active-passive polymer mixtures

## TL;DR

This study demonstrates through simulations that in active-passive polymer mixtures, small activity differences can induce phase separation at lower activity ratios, aiding experimental observation and providing insights into cellular DNA organization.

## Contribution

It reveals that polymer length influences the critical activity ratio for phase separation, making the phenomenon more experimentally accessible and relevant to biological systems.

## Key findings

- Polymer length decreases the critical activity ratio for phase separation.
- Entropy production accurately indicates the non-equilibrium phase transition.
- Phase separation occurs at lower activity ratios in polymer mixtures compared to colloids.

## Abstract

Recent theoretical studies found that mixtures of active and passive colloidal particles phase separate but only at very high activity ratio. The high value poses serious obstacles for experimental exploration of this phenomenon. Here we show using simulations that when the active and passive particles are polymers, the critical activity ratio decreases with the polymer length. This not only facilitates the experiments but also has implications on the DNA organization in living cell nuclei. Entropy production can be used as an accurate indicator of this non-equilibrium phase transition.