Interfacial Properties of Active-Passive Polymer Mixtures.

Area of Science:

• Soft Matter Physics
• Non-equilibrium Thermodynamics
• Polymer Science

Background:

• Active matter systems, characterized by energy-dissipating particles, are relevant to biological processes like DNA strand separation in cells.
• Understanding phase separation in active-passive polymer mixtures is crucial for modeling cellular organization.

Purpose of the Study:

• To investigate the interfacial properties of phase-separated active-passive polymer mixtures.
• To compare non-equilibrium steady states with equilibrium phase separation.
• To establish a mechanistic definition of interfacial stiffness in active systems.

Main Methods:

• Modeling active constituents with enhanced fluctuations.
• Utilizing entropy production as a phase transition indicator.
• Constructing phase diagrams and analyzing particle kinetics near interfaces.

Main Results:

• Entropy production accurately predicts phase transitions.
• Interface fluctuations follow the capillary wave spectrum.
• Interfacial stiffness and width are dependent on the activity ratio.

Conclusions:

• Non-equilibrium phase separation in active-passive polymers shares similarities with equilibrium systems.
• The study provides a mechanistic understanding of interfacial properties in active matter.
• Identified general principles for non-equilibrium phase separation applicable to biological systems.