Intrachain Ordering and Segregation of Polymers under Confinement

Abstract

We study the relationship between intrachain ordering and segregation tendency of two polymers confined in a cylindrical space. We find the chains segregate spontaneously even outside de Gennes' linear-ordering scaling regime, in which each chain is a linear array of blobs. When the chains are weakly compressed against each other, linear ordering is well preserved and the chains remain segregated. On the other hand, for moderate compression, new chain-ordering units emerge at intermediate length scales, within which blobs are randomly packed; yet these units (termed "superblobs") are linearly ordered, and the chains still segregate in the confined space. As the chains continue to be compressed, the linear regime disappears, but the chains can resist mixing effectively, more so in a more asymmetric space. We conclude that the linearly ordered E. coil chromosome is in the segregation regime.