胶体动力学自组装中稳态结构形成的探索

Dynamic self-assembly is the self-assembly far from equilibrium, and usually accompanied with energy input and dissipation, this mechanism could lead to rich and novel self-organization structures. Especially, formation of steady states observed in some dynamic systems has been a research focus. Our understanding of dynamic self-assembly, however, is still very limited. The emergence of complicated collective behavior in dynamical systems makes it a great challenge of research. In this project, we propose to investigate the formation of steady states in colloid via dynamic self-assembly. This research may not only promote our theoretical understanding of dynamic self-assembly but also shed light on the design of new intelligent material which is in urgent need. In order to achieve steady states with colloidal crystal or gel structure, we provide a procedure combining simulation and theory. Firstly, we will use computer simulation to find out the implementation conditions and characteristics of the steady states, focusing on the dynamic evolution. Secondly, we will try to discover the underlying physics from dynamics and statics, and construct the theoretical framework for colloid dynamic self-assembly. Last, we will generalize our knowledge about dynamic self-assembly based on the study of colloidal systems, and lay a foundation for the future study of other complex dynamic systems.

动力学自组装是远离平衡态的自组装行为，通常伴随着能量的输入和耗散，展现出丰富而新颖的自组装现象。对动力学自组装形成稳定态的研究是近年国际上关注的一个热点。但目前人们对动力学自组装物理的认识还远远不够深入，体系中复杂集体行为的出现给研究带来极大挑战。在本项目中，我们提出研究胶体动力学自组装形成稳定结构的物理图像。此项研究将不仅能够提升我们对动力学自组装的理论认识，还有可能为发展新型智能材料提供新的思路。为了实现胶体通过动力学自组装形成稳定的胶体晶体或胶体凝胶结构，我们提出了一套完整可行的研究方案。首先，我们将采用计算机模拟，找出动力学稳定结构实现的条件和特点，并关注动力学演变过程；其次，从动力学和静力学两方面入手，揭示其物理本质，建立胶体动力学自组装的理论框架；最后，我们将在总结胶体动力学自组装的基础上，研讨动力学自组装的较普遍理论，为今后研究更为复杂的动力学体系打下基础。

非平衡态自组装是目前自组装领域的一个重要课题。对这一领域的研究，目前国内外都处于起步且不断发展的阶段。通过不同形式的外界能量的输入，自组装出不同于平衡态条件下的结构，为新型功能材料的实现提供了更多的可能。我们在这个项目的资助下，完成了三方面的工作。1.通过引入振荡溶液pH值，我们在一种带相反电性的高分子胶体球体系实现了非密堆胶体晶体结构。其中石墨烯结构和钻石结构都是胶体晶体中稀有的结构。这些非密堆结构的实现，为胶体晶体的应用创造了更大的空间。2.受到生物活细胞的启发，我们在准二维椭球体系中考虑了一种具有周期性伸缩功能的边界（活性边界）。发现受限于活性边界中的椭球粒子，能够实现平衡态条件下从未出现过的长程的有序的动力学稳定结构。解决了平衡态体系高密度椭球粒子很难实现长程有序的难题。3.在带电的椭球小球混合体系，我们通过两个同步振荡的平面受限，实现了具有光俘获能力的光子晶体薄膜材料。这些工作为胶体体系的自组装提供了新的思路，也为我们探究更多非平衡态的复杂结构提供了基础。