Long-range correlations in a polymer chain due to its connectivity

TitleLong-range correlations in a polymer chain due to its connectivity
Publication TypeJournal Article
Year of Publication2008
AuthorsD Shirvanyants, S Panyukov, Q Liao, and M Rubinstein
Pagination1475 - 1485
Date Published01/2008

The analysis of intrachain monomeric interactions reveals a new effect in the description of polymer conformations in dilute theta-solutions, semidilute solutions, and melts. The chain connectivity modifies the effective monomeric interaction, which results in the long range correlations between orientations of polymer bonds, that decay as a power law. A major modification of the standard polymer models was made to describe this effect. We predict the power-law decay of the bond-vector correlation function of a polymer in the theta-solvent, \textless a(i)a(j)\textgreater similar to vertical bar i-j vertical bar(-3/2), (a(i) is the ith bond vector) instead of commonly assumed exponential decay. We calculated the length dependence of the ratio of the mean squared size of a chain segment to its length s. Our theory predicts that this ratio has a maximum below the theta-point due to the balance of the new effective interaction and the two-body attraction. The Flory characteristic ratio C-n of a chain with n main chain bonds is found to approach its asymptotic value C-infinity as n(-1/2) and not as n(-1), predicted by the classical polymer models. We show that the necessary conditions for the existence of new effective interactions is the chain connectivity and nonzero range of monomeric interactions.

Short TitleMacromolecules