New types of pattern formation caused by the competition between non-equilibrium phenomena

通常模式形成伴随着非平衡现象，如相分离。如果两个以上的非平衡现象相互耦合，则有望形成新的模式。通过两种非平衡现象之间的竞争获得的最终形态不能用平衡相图或热力学来预测。它是由两个非平衡过程之间的竞争在动力学上决定的。非平衡现象之间的竞争将为我们提供新的形态类型，这是单次有序过程永远无法获得的。原则上，这些现象应该用描述非平衡现象的耦合方程来预测。方程的非线性和非局域性给理论预测带来了困难。我们已经从实验和理论上研究了这个复杂而重要的现象。我们使用了自己开发的数字图像分析（DIA）方法来研究图案的形成。所研究的耦合现象有：(1)相分离与结晶，(2)相分离与化学反应，(3)相分离与润湿。在情形(1)中，我们发现了凝固对相分离的钉住作用和相分离引起的球晶带状组织。案例(2)表明，化学反应速度与相分离速度之间的关系主导着畴的图案演化和界面结构。如果两组分聚合物之间的化学反应速度比相分离慢，则化学反应在界面处发生效率最高，可能形成改性界面。在情形(3)中，我们发现几何约束强烈地影响图样演化和由此产生的结构。在润湿作用下，模式形成的动力学基本得到了澄清。在本研究中，我们旨在了解两种非平衡现象竞争下图案形成的基本物理原理，并开发新的形态控制方法。近年来，非均相聚合物合金的形貌与其物理性能之间存在着很强的相关性。从这方面来看，形貌控制是设计具有理想物理性能的聚合物合金半宏观结构的重要技术之一。基本上，上述新型的形态控制技术甚至适用于没有相图的非混相聚合物共混物。在这种情况下，应考虑机械混合过程与化学反应等其他非平衡现象之间的竞争。我们希望这项研究将为我们提供新的形态控制技术和新的材料类别。少

Usually pattern formation is accompanied by nonequilibrium phenomena such as phase separation. If more than two nonequilibrium phenomena are coupled with each other, new types of pattern formation are expected. The final morphology obtained by competition between two nonequilibrium phenomena cannot be predicted by an equilibrium phase diagram, or thermodynamically. It is kinetically determined by competition between two nonequilibrium processes. Competition between nonequilibrium phenomena should provide us with new types of morphologies, which can never be obtained by single ordering process. In principle, the phenomena should be predicted by coupled equations describing nonequilibrium phenomena. The nonlinear and nonlocal characters of the equations make the theoretical prediction difficult. We have studied this complicated, but important phenomena both experimentally and theoretically. We have used the digital image analysis (DIA) method developed by us for studying pattern formatio … More n dynamics.The coupling phenomena studied were as follows: (1) Phase separation and crystallization, (2) phase separation and chemical reaction, and (3)phase separation and wetting. In case (1), we have found the pinning of phase separation by solidification and also the banded structure of spherulite induced by phase separation. In case (2), it has been demonstrated that the relation between the chemical reaction speed and the phase separation speed dominates the pattern evolution and the interface structure of domains. If chemical reaction between two component polymers proceeds more slowly than phase separation, chemical reaction should occur most efficiently at interface and modified interface can probably be formed. In case (3), we have found that the geometrical confinement strongly affects the pattern evolution and the resulting structure. The dynamics of pattern formation under the wetting effect has mostly been clarified.In this research, we have aimed at understanding the basic physics of pattern formation under competition between two nonequilibrium phenomena and developing new methods for morphology control. Recently it has been well established that there is strong correlation between morphology of heterogeneous polymer alloy and its physical properties. From this aspect, the morphology control is one of the most important techniques for designing the semi-macroscopic structure of polymer alloy with desired physical properties. Basically the above new types of morphology-control techniques should be applicable even for immiscible polymer blends without phase diagrams. In that case, the competition between mechanical mixing process and other nonequilibrium phenomena such as chemical reaction should be considered. We hope that this study will provide us with new techniques of morphology control and new classes of materials. Less