结晶、玻璃化以及有序和无序的关联

Being the two extremes of the liquid-solid transition, crystallization and glass transition are cutting-edge topics of physical, chemical, materials, and biological sciences. In particular, the nature of the glass transition is a long-standing unsolved problem of condensed matter physics. This project will take the soft matter systems of colloids as the object of study. We will employ molecular simulations and experiments to study the crystallization, glass transition, and the deep connection possible existing between order and disorder, from perspectives of the structure, dynamics, and thermodynamics. The project has two major targets, comparing the microscopic kinetic pathways of the crystallization and glass transition, and understanding the transitions from order to disorder. Specifically, we will study the formation and frustration of the nucleation precursors, the influence of the boundary on the kinetic pathways of crystallization and glass transition, the transition from crystallization to glass transition, the transition in solids from crystals to disordered crystals, and the transition from close packing to random close packing. The project is designed based on our long-term study of the crystallization and glass transition. It contains creative ideas, contents, methods, and techniques. We aim at investigate the nature of the glass transition from new perspectives, along with the deepening of our understanding of order and disorder.

结晶和玻璃化作为液-固转变的两个极端，一直以来都是物理、化学、材料、生物等学科研究的前沿课题，尤其是玻璃化转变，其本质是长期困扰凝聚态物理学的难题。本项目以软物质胶体体系为主要研究对象，结合分子模拟和实验，从结构、动力学、热力学等多个角度全方位深入探讨结晶和玻璃化、有序和无序之间可能存在的深层次关联。整个研究包含两个大方向：结晶和玻璃化微观动力学路径的比较和有序-无序转变。具体包括结晶前驱体的形成和受阻机理、边界对结晶和玻璃化微观路径的影响、结晶到玻璃化转变的演变、固体中存在的晶体-无序晶体转变、密堆积和随机密堆积之间的演变等研究内容。本项目基于研究组对结晶和玻璃化相关研究的长期积累，在研究思路、内容和技术方法等方面都有创新，将在深化对有序和无序认识的同时，尝试从新的视角探讨玻璃化转变的本质。

项目采用理论计算模拟和实验手段，从结构、动力学、热力学等多个角度全方位深入探讨结晶和玻璃化这两类分别形成结构有序的晶体和结构无序的非晶固体（如玻璃）的液-固转变的基础物理问题，进而探寻有序和无序之间的潜在关联。在项目的支持下，我们大力推进了对结晶微观机理和动力学路径、过冷液体动力学、非晶固体结构特性、非晶液固转变本质等的认识，发现了多项强有力的证据用来揭示平衡和非平衡、有序和无序之间深层次的关联。项目基本完成了预期目标，取得了一系列重要的成果，发表了21篇SCI论文，其中包括1篇Nature Physics、1篇Nature Materials、2篇Science Advances、3篇Nature Communications和3篇Physical Review Letters。代表性的研究成果包括：发现了极低温条件下无扩散、多米诺骨牌模式的快速结晶并解释了其机理；发展了新的实验手段，揭示了限域条件下带电胶体结晶的不同路径和形貌选择的机理；发现了短程吸引体系Jamming转变的双尺度非平衡刚性逾渗相变的新奇特性；揭示了两组分玻璃形成液体的玻璃形成能力与晶体熔化温度之间的关联；构建了零温非晶固体的涨落-耗散关系，发现慢演化非平衡体系的有效温度其实就是结晶温度或与之相关的玻璃形成液体的起始温度，从而进一步揭示了平衡与非平衡、有序与无序的关联。