Models of flexible polymers in good solvents: relaxation and coil–stretch transition

Abstract

We analyze the impact of solvent quality on relaxation dynamics and the coil–stretch transition (CST) using Brownian dynamics simulations of a new bead–spring model. A new spring force relation, which can represent the polymer in theta to good solvent, is developed to obtain the force–extension (FE) behavior of molecules. Due to different regions of the FE curve, we find that the relaxation and CST behavior are altered. A simple force balance is used to explain different regions of the flow and relaxation behavior. Using a model that neglects conformation dependent drag, it is found that some molecules will have two different exponential decays in relaxation and the CST will be modified for others.