Eur. Phys. J. E 4, 327-336
Early stages of phase separation from polydisperse polymer mixtures
N. ClarkeDepartment of Chemistry, University of Durham, Science Laboratories, South Road, Durham, DH1 3LE, UK nigel.clarke@durham.ac.uk
(Received 29 June 2000 and Received in final form 20 November 2000)
Abstract
We study the early stages of phase separation in a
mixture of a polydisperse and a monodisperse polymer within the
Cahn-Hilliard framework. We model the polydisperse component
using a finite, but arbitrarily large, number of components, and
show that the number of components required for convergent
behaviour to be achieved is computationally undemanding. We study
the growth rate of fluctuations following a quench into the two-phase
region of the phase diagram. The q-dependence of the
growth rate is shown to be commensurate with the behaviour of a
monodisperse-monodisperse mixture, with the major difference
being an effective mobility that is dependent on the quench
depth. We also study the deviation of the time dependence of the
scattering function from single exponential behaviour.
64.75.+g - Solubility, segregation and mixing; phase separation.
61.41.+e - Polymers, elastomers, and plastics.
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2001
