Internal structure and dynamics of dilute linear polymers

Abstract

We report measurements of the internal structure and dynamics of a dilute high molecular weight polymer in good and 0 solvents, with a special emphasis on the form of the decay of internal modes. Intermediate elastic light scattering measurements show that the static structure exhibits the expected selfavoiding walk and random-walk fractal dimensions in good and 0 solvents, respectively. Quasielastic light scattering studies of the relaxation of internal "Zimm" modes demonstrate the universal q3 dependence of the initial decay rate on the scattering wavevector. However, the primary goal of this work, to observe the expected stretched exponential time decay exp[-(t/~)~] with the Zimm exponent b = 2/3, was difficult to achieve, even though we used the h = 331.6 nm UV line of an argon ion laser to monitor relaxations on length scales much smaller than the polymer radius. In a good solvent we obtained b = 0.72, and in a 8 solvent we obtained b = 0.71. We compare these results to extant experimental and theoretical work.

Physical Chemistry of Polymers: Entropy, Interactions, and Dynamics

“…The intermediate regime, with qR g > 1 and qb < 1, follows the internal modes of the chain. Here the Zimm theory predicts that S ( q , t ) is a function of t 1/3ν , which has been confirmed experimentally . (Note the correspondence between this exponent and that for G *(ω) when ωτ 1 ≫ 1.)…”

“…Here the Zimm theory predicts that S(q,t) is a function of t 1/3ν , which has been confirmed experimentally. 97 (Note the correspondence between this exponent and that for G*(ω) when ωτ 1 . 1.)…”

Dynamical properties of branched polymeric clusters in dilute regime

“…where r,(t) is the position of the I-th More generally, we have f Cc nR~~ ( 5) where Z is a dynamical exponent. In the two limiting cases mentioned above, Z is equal to 3 (dimension of the space) and equal to 2 + D respectively.…”

Review of Light Scattering Literature

“…Martin, et al [ 17] studied the internal structure and dynamics of dilute linear polymers by probing the dynamic light scattering in the intermediate scattering region where qRg >> I. The intermediate scattering regime was reached by using high molecular weight polystyrene with a large radius of gyration.…”