Theory of Polymer Crystallization

当今大多数材料都是由聚合物制成的，这构成了一个价值数十亿美元的产业。无论是塑料杯、包装材料、高性能纳米和微型设备、服装材料还是飞机部件，这些都是通过聚合链制造的。如何在各种外部施加的条件下控制聚合物组织成理想结构的理解目前尚不清楚。然而，这种理解对于颁布制造新材料的设计规则以及改善现有材料的性能至关重要。所提出的研究将有助于从动力学途径和有序结构的出现方面理解聚合物结晶。这一建议旨在建立新的概念模型，发现聚合物结晶的新规律。此外，提出的理论工作补充了世界范围内正在积极进行的许多实验工作。所提出的研究结果将在许多应用领域产生影响，如聚合物加工和聚合物纳米材料的制造。在这个具有挑战性的研究领域培养研究生是该提案强有力的教育组成部分。聚合物的结晶充满了阴谋和聚合物链如何组织成层次结构的基本理解仍然是难以捉摸的。利用先进的理论和计算工具来解释构象熵和拓扑缺陷的独特属性，并与组装的焓驱动力合作，本建议解决(a)单晶形态和平片、空心金字塔、碗状、卷轴和扭曲片的相对稳定性，(b)熔化动力学，以及(c)熔体记忆的起源。这一建议旨在建立新的概念模型，发现聚合物结晶的新规律。此外，提出的理论工作补充了世界范围内正在积极进行的许多实验工作。所提出的研究结果将在许多应用领域产生影响，如聚合物加工和聚合物纳米材料的制造。今天的大多数材料都是通过加工半结晶聚合物制成的。这些材料构成了一个价值数十亿美元的产业。对这类重要聚合物材料的基本行为的理解将有助于设计和加工新型聚合物材料，为我们的社会带来更大的利益。在这个具有挑战性的研究领域培养研究生是本提案强有力的教育组成部分。

Nontechnical SummaryMost of the materials today are made from polymers constituting a multi-billion-dollar industry. Whether we think about plastic cups, packaging materials, high-performance nano- and micro-devices, clothing materials, or aircraft parts, these are fabricated through polymeric chains. An understanding of how to control organization of polymers into desirable structures under a variety of externally imposed conditions is currently missing. However, such an understanding is vital to promulgate design rules for making new materials as well as for improving the performance of the materials available today. The proposed research will contribute to the understanding of polymer crystallization in terms of both kinetic pathways and the emergence of the ordered structures. This proposal is aimed at building new conceptual models and discovering new laws of polymer crystallization. In addition, the proposed theoretical work complements many experimental efforts being actively pursued worldwide.The results of the proposed research will have impact in numerous applied areas such as polymer processing, and fabrication of polymeric nanomaterials. Training of graduate students in this challenging research area is the strong educational component of this proposal.Technical SummaryCrystallization of polymers is full of intrigue and a fundamental understanding of how polymer chains organize into hierarchical structures continues to be elusive. Using advanced theoretical and computational tools to account for the unique attribute of the conformational entropy and topological defects in cooperation with enthalpic driving forces for assembly this proposal addresses (a) single crystal morphology and relative stabilities of flat lamellae, hollow pyramids, bowls, scrolls, and twisted lamellae, (b) kinetics of melting, and (c) origin of melt-memory. This proposal is aimed at building new conceptual models and discovering new laws of polymer crystallization. In addition, the proposed theoretical work complements many experimental efforts being actively pursued worldwide.The results of the proposed research will have impact in numerous applied areas such as polymer processing, and fabrication of polymeric nanomaterials. Most of the materials today are made by processing semicrystalline polymers. These materials constitute a multi-billion-dollar industry. A fundamental understanding of the behavior of this important class of polymeric materials will help to design and process novel polymeric materials with enhanced benefits to our society. Training of graduate students in this challenging research area is strong educational component of this proposal.