Percolation of Phase-Separating Polymer Mixtures
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- 作者：Di-Yao Hsu ; Che-Min Chou ; Ching-Yen Chuang ; Po-Da Hong
- 刊名：ACS Macro Letters
- 出版年：2015
- 出版时间：December 15, 2015
- 年：2015
- 卷：4
- 期：12
- 页码：1341-1345
- 全文大小：408K
- ISSN：2161-1653
文摘
We study the percolation problem in a binary phase-separating polymer mixture. By well-designed experiments, we can delineate the percolation line on the phase diagram with sufficient accuracy. Our experiments show that the percolation thresholds start from the random percolation limit (桅 鈭?0.15) located near spinodal point at T 鈫?Tc and then converge toward the geometric coalescence limit (桅 鈭?0.36) with an increase in the quench depth. This apparent percolation difficulty comes about largely from the Rayleigh instability accompanied by large-amplitude, short-wavelength fluctuations during the spinodal decomposition at deeper quench depth. As a result, the broken 鈥渞igid鈥?domains tend to pack closely, and the so-called droplet spinodal decomposition occurs. On the other hand, we observe that, between the selectively attractive walls, the surface-drying percolating phase will break up into droplets prematurely, thereby shifting its percolation line rather considerably. To our knowledge, such an effect is not yet predicted by theory or simulation.