Regensburg 2025 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
CPP: Fachverband Chemische Physik und Polymerphysik
CPP 45: Charged Soft Matter, Polyelectrolytes and Ionic Liquids II
CPP 45.4: Vortrag
Freitag, 21. März 2025, 12:15–12:30, H38
Condensate size control by charge asymmetry — •Chengjie Luo1, Nathaniel Hess2, Dilimulati Aierken2, Yicheng Qiang1, Jerelle A. Joseph2, and David Zwicker1 — 1Max Planck Institute for Dynamics and Self-Organization — 2Princeton University
Biomolecular condensates are complex droplets composed of various types of biomolecules, including nucleic acids and proteins. These condensates form mainly due to liquid-liquid phase separation, which is driven by short-range attraction between biomolecules. Typical biomolecules carry various net charges, so that long-ranged electrostatic interactions could affect phase separation. We study this situation using a simple model of two short-ranged attractive polymers with opposite charges and their counterions. We find that the charged polymers segregate from the solvent, and thus form two macrophases, when their charges are symmetric. In contrast, many droplets of equal size coexist when charge asymmetry is sufficiently strong. Such patterned phases form because the short-range attraction concentrates polymers within droplets, leading to net charges, which prevents droplet growth. Our molecular dynamics simulation and a continuous field theory demonstrate that droplet size decreases with charge asymmetry. Overall, we present a mechanism controlling droplet size via a trade-off between short-ranged attraction driving phase separation and long-ranged electrostatic repulsion if droplets accumulate net charges. Our results are relevant for understanding biomolecular condensates and creating synthetic patterns in chemical engineering.
Keywords: phase separation; charged polymers; droplets; electrostatic interaction; charge asymmetry