Authors: Y. Shang, M. Wei, D. Kazmer, J. Mead, C. Barry
Affilation: University of Massachusetts, Lowell, United States
Pages: 662 - 665
Keywords: nano, modelling, phase separation, spinodal, patterned substrate
Phase separation of an asymmetric immiscible binary polymer system in an elastic field with the existence of a heterogeneously functionalized substrate surface was numerically studied in 2D and 3D. An unconditionally stable method for time marching the Cahn-Hilliard equation was employed in the numerical simulation. Compared to the conventional interface tracking mechanism, this diffusion controlled system is characterized by the thick interface with composition gradients. The evolution mechanisms were studied. It can be observed that the characteristic length, LC, of the phase separation morphology patterns was measured with the Fast Fourier Transform method. The order of the phase separation are investigated, and indicated that LC1/3 increased linearly with time. The influence of the material composition, the attraction factor on the template, and the gradient energy coefficient between the two polymers on the resulting patterns were also observed in this study. The analytical results were compared with experiment. Qualitative and quantitative correspondence can be observed between the numerical results and the experiment results.