A Quantitative Approach to Brownian Motions of Polymers under Flow

A quantitative method is proposed for studying self-correlations of polymers under flow. Analysis of nonequilibrium molecular dynamics simulations shows that in the flow frame the probability density functions of center of mass displacements can be described by superdiffusive, anisotropic Gaussian distributions. This behavior originates from interactions between centers of mass of polymers, which cannot be properly treated by mean-field models. Additionally, the segmental fluctuations in the polymer frame are strongly suppressed by flow. The origin of this phenomenon will be discussed.