2022 Impact factor 1.8
Soft Matter and Biological Physics

Eur. Phys. J. E 4, 161-171

Kinetics of microphase segregation in one-dimensional symmetric diblock copolymer systems

V.A. Pryamitsyn1, A.N. Semenov2 and T.C.B. McLeish1

1  I.R.C. in Polymer Science & Technology, Department of Physics & Astronomy, University of Leeds, Leeds, LS2 9JT, UK
2  Department of Applied Mathematics, University of Leeds, Leeds, LS2 9JT, UK


(Received 10 March 2000 and Received in final form 5 June 2000)

An analytical one-dimensional model of the microphase separation in symmetric diblock copolymers is developed. Three stages of the process of the microphase segregation of a quenched diblock copolymer system into a lamella structure are predicted. The first stage involves a fast increase of the amplitude of the quasi-periodical lamella structure (with the average wave vector q0) up to a nearly equilibrium value; the second stage is a slow phase diffusion process which is characterized by increasing coherency of the lamella structure; the third stage is the slow process of the lamella swelling, which is driven by the thermally activated process of the spontaneous deletion of excessive lamellas, the lamella size increasing from the initial value $2\pi/q_0$ to the equilibrium $2\pi/q_\ab{eq}> 2\pi/q_0$ during the process. The last two stages are described with the specially introduced coarse-grained "amplitude-phase" approximation. It is shown that the relaxation of the gradient of the phase of the lamellar structure is the slowest relaxation process and, thus, can be used as an effective order parameter of the lamellar structure at the later stages of the microphase segregation.

36.20.Ey - Macromolecules and polymer molecules: Conformation (statistics and dynamics).
83.70.Hq - Heterogeneous liquids: suspensions, dispersions, emulsions, pastes, slurries, foams, block copolymers, etc..

© EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2001