A computational method for the spinodal decomposition is presented on the basis of a nonlinear theory proposed by Langer, Bar-on, and Miller [Phys. Rev. A 11, 1417 (1975)] (LBM) with an application of Suzukis [Prog. Theor. Phys. 56, 77 (1976); 56, 477 (1976); 57, 380 (1977); Adv. Chem. Phys. 46, 195 (1981); J. Stat. Phys. 49, 977 (1987)] general scaling theory for transient phenomena. The results were compared with experimental observations for a typical polymer-blend system with respect to the experimentally accessible quantities such as the structure factor and the single-point distribution function. The main features observed in scattering experiments were reproduced by this method. The inequality >3 was found in the numerical analyses when fitting the power-law relations expressed by qmt- and Smt to the time variations of the dominant Fourier component of concentration fluctuations qm and the corresponding structure factor Sm. It is shown that the LBM theory can be used to describe the phase-separation behavior up to intermediate stages.
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics