Growth of equilibrium polymers under non-equilibrium conditions

Abstract

We investigate the kinetics of self-assembly by means of Brownian dynamics simulationbased on a idealized fluid model (two ‘sticky’ spots on a sphere) in which the particles areknown to form into dynamic polymer chains at equilibrium. To illustrate the slowevolution of the properties of these self-assembling fluids to their equilibriumassembled state values at long times, we perform Brownian dynamics simulations overa range of quench depths from the high temperature unassembled state to thelow temperature assembled state. We investigate the time dependence of theaverage chain length (cluster mass), the order parameter for the assembly transition(fraction of particles in the chain state) and the potential energy of the fluid.The rate constant governing the self-assembly ordering process depends both onkinetic-related factors (the particle hydrodynamic radius and the fluid viscosity) and onthermodynamic energetic variables governing the self-assembly transition (i.e.,the entropy and enthalpy of assembly). We provide evidence that an essentiallyparameter-free description of the polymerization kinetics can be formulated for this model.