Equilibrium phase diagram of semi-flexible polymer networks with linkers

¹ Institute for Computational Mechanics, Technische Universität München - D-85748 Garching, Germany, EU
² Lehrstuhl für Zellbiophysik E27, Technische Universität München - D-85748 Garching, Germany, EU
³ Department of Physics and Astronomy, University of California - Los Angeles, CA 90095, USA
⁴ California NanoSystems Institute, University of California - Los Angeles, CA 90095, USA

Received: 1 March 2013
Accepted: 1 May 2013

Abstract

We present the determination by numerical simulation of the equilibrium phase diagram of solutions of semi-flexible polymers with linker molecules. At low linker concentrations the solution forms an isotropic gel phase. At higher linker concentrations we encounter —depending on the properties of the linker molecules— bundle phases, liquid-crystalline mesophases with broken bond-orientational order that had been predicted by analytical theories, and in addition a novel equilibrium state: the cluster phase. Equilibrium condensation of semi-flexible polymers appears to be controlled by linker entropy. The results are compared with the phase behavior of solutions of biopolymers and linker proteins.