Theory of Polymer Crystallization and Melting

聚合物结晶和熔融理论

• 批准号: 1713696
• 负责人: Murugappan Muthukumar
• 金额: $ 38.1万
• 依托单位: University of Massachusetts Amherst
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-01 至 2020-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1713696&HistoricalAwards=false
• 关键词: Theory; Polymer; Crystallization; Melting

NONTECHNICAL SUMMARYThis award supports theoretical and computational research and education on how long chain-like molecules or polymers, crystallize. Consider a collection of tangled wires and think about organizing them into well-ordered crystals. Such a seemingly difficult task, however, occurs naturally and readily in the real world even for the simplest polymers such as polyethylenes. In fact, most of the materials today are made from such semicrystalline polymers, which constitute a multi-billion-dollar industry. An understanding of the crystallization process of polymers is one of the longstanding research challenges in the materials world, primarily due to the haphazard and random configurations of the polymer molecules before they organize into crystals. As a result, the phenomenon of polymer crystallization is challenging with few unifying conceptual themes. This research program is geared towards development of fundamental concepts to understand how polymers crystallize and melt, using theory and modelling. A fundamental understanding of the behaviours of this important class of materials will help to design and process novel polymeric materials with enhanced benefits to our society. This project includes training graduate students in this challenging research area of tremendous societal value.TECHNICAL SUMMARYThis award supports theoretical and computational research and education on how polymers crystallize. Crystallization of polymers from solutions and melts is one of the longstanding research areas in polymer science with tremendous industrial value, full of intrigue without unifying conceptual themes. A fundamental understanding of how polymer chains organize into hierarchical crystalline structures remains elusive. The most significant endowment of flexible polymer molecules is their conformational entropy. This attribute sets the crystallization and melting behaviours of polymers to be distinct from other ordering phenomena of small molecular systems. This research project is aimed to develop fundamental concepts behind polymer crystallization and melting, by accounting for conformation entropy of polymer chains and topological defects under non-equilibrium conditions. The principal investigator will employ statistical mechanics, field theory, and various simulation techniques in the development of new theories of polymer crystallization and melting. More specifically, the research project will address (a) single crystal morphology - topological defects driving sectorization in lamellae and relative stabilities of flat lamellae, hollow pyramids, scrolls, and twisted lamellae, (b) kinetics of melting and recrystallization of polymer crystals, and (c) macromolecular origin of melt-memory in polymer crystallization.The results from the research program may have impact in the multi-billion-dollar industry of polyolefins and also in numerous applied areas such as polymer processing, and fabrication of polymeric nanomaterials. Training graduate students in this challenging research area is a strong educational component of the research program.

非技术摘要这一奖项支持理论和计算研究和教育，涉及链状分子或聚合物的长期结晶。考虑一系列纠结的电线，并考虑将它们组织到有序的晶体中。然而，即使对于最简单的聚合物（例如聚乙烯），这一看似艰巨的任务也自然而容易地发生在现实世界中。实际上，当今的大多数材料都是由这种半晶体聚合物制成的，这些聚合物构成了数十亿美元的行业。对聚合物的结晶过程的理解是材料世界中长期研究的挑战之一，这主要是由于聚合物分子在组织成晶体之前的随意和随机构型。结果，聚合物结晶的现象具有挑战性，几乎没有统一的概念主题。该研究计划旨在发展基本概念，以了解聚合物如何使用理论和建模来结晶和融化。对这一重要材料类别的行为的基本理解将有助于设计和处理新颖的聚合物材料，并增强对我们社会的好处。该项目包括在这个具有巨大社会价值的挑战性研究领域的培训研究生。技术摘要奖支持了有关聚合物如何结晶的理论和计算研究和教育。从解决方案和融化的聚合物结晶是具有巨大工业价值的聚合物科学的长期研究领域之一，充满了阴谋，而无需统一概念主题。对聚合物链如何组织成层次结构结构的基本理解仍然难以捉摸。柔性聚合物分子的最显着赋是它们的构象熵。该属性将聚合物的结晶和熔化行为设置为与小分子系统的其他有序现象不同。该研究项目的目的是通过考虑在非平衡条件下聚合物链和拓扑缺陷的构象熵来开发聚合物结晶和融化背后的基本概念。主要研究者将采用统计力学，现场理论和各种仿真技术来开发聚合物结晶和融化的新理论。更具体地，研究项目将解决（a）单晶体形态 - 拓扑缺陷可在薄片中驱动扇区以及扁平层，空心金字塔，卷轴和扭曲的薄片的相对稳定性，（b）融化和重新结晶的聚合物晶体晶体和（c）crymer crymer sallos of Crymer的动力学的动力学，并将其构成。可能会影响聚集素的数十亿美元行业，以及在聚合物加工等众多应用领域以及聚合物纳米材料的制造。在这个充满挑战的研究领域的培训研究生是研究计划的强大教育组成部分。

项目成果

Trends in polymer physics and theory

• DOI: 10.1016/j.progpolymsci.2019.101184
• 发表时间: 2020-01-01
• 期刊: PROGRESS IN POLYMER SCIENCE
• 影响因子: 27.1
• 作者: Muthukumar, Murugappan

Surface Tension of Dielectric–Air Interfaces

电介质与空气界面的表面张力

• DOI: 10.1021/acs.jpcb.0c01430
• 发表时间: 2020
• 期刊: The Journal of Physical Chemistry B
• 作者: Kumar, Rajeev;Muthukumar, Murugappan
• 通讯作者: Muthukumar, Murugappan

Theory of statistics of ties, loops, and tails in semicrystalline polymers

• DOI: 10.1063/1.5113595
• 发表时间: 2019-09-21
• 期刊: JOURNAL OF CHEMICAL PHYSICS
• 影响因子: 4.4
• 作者: Adhikari, Sabin;Muthukumar, Murugappan
• 通讯作者: Muthukumar, Murugappan