Intramolecular relaxation of polystyrene in a theta solvent by photon-correlation spectroscopy |
| |
Authors: | Gwynne Jones David Caroline |
| |
Institution: | School of Physical and Molecular Sciences, University College of North Wales, Bangor Gwynedd LL57 2UW, UK |
| |
Abstract: | Photon-correlation spectroscopy has been used to measure the diffusion coefficient D and first-mode intramolecular relaxation time τ1 of polystyrene in a theta solvent, cyclohexane at 34.5°C. Measurements were made on five narrow fractions (w = 2.88 × 106 to 9.35 × 106) as a function of concentration c, in the dilute regime. D varied linearly with c, D = Do (I + kDc), with Do = (1.4 ± 0.2) × 10?4 cm2 s?1. Although the values obtained for τ1 were reproducible to within 5%, no systematic variation with c was detected. The results are fitted by the relation τ1 = (7.7 ? 0.3) × 10?8 μs, which agrees well with the theoretical expression of Zimm for the non-draining bead-and-spring model, modified for the light-scattering case. |
| |
Keywords: | |
本文献已被 ScienceDirect 等数据库收录! |
|