Grains and Defects in Block Copolymers

嵌段共聚物中的晶粒和缺陷

• 批准号: 9901951
• 负责人: Bruce Garetz
• 金额: $ 28.3万
• 依托单位: Polytechnic University of New York
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-05-01 至 2002-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9901951&HistoricalAwards=false
• 关键词: Grains; Defects; Block; Copolymers

9901951BalsaraAn experimental study, aimed at obtaining a fundamental understanding of the factors that control grain and defect structure in block copolymers, is proposed. Block copolymers belong to a general class of materials that exhibit a symmetry-breaking phase transition from a disordered phase to ordered nanostructures with liquid crystalline symmetry. Typical examples include lamellae, and cylinders arranged on a hexagonal lattice. However, coherent order in these materials is restricted to finite regions or grains, with concomitant defects. This proposal addresses three issues: nucleation of grains, defect dynamics, and the microscopic response of grains to macroscopic deformation. The primary tool that we will use to obtain the grain structure is depolarized light scattering. The relationship between optical properties and block copolymer grain structure (size, shape, and inter-grain correlations) was established in our laboratory. The optical experiments will be augmented by electron microscopy, neutron scattering, and rheology. Samples required for the initial studies have already been synthesized by high vacuum anionic polymerization; additional samples will be synthesized as necessary.The students who will be supported by this grant will be educated in the areas of polymer synthesis, polymer characterization by spectroscopy and chromatography, scattering of light, X-rays, and neutrons, and condensed matter physics. Such interdisciplinary training is become increasingly important in government and industrial research laboratories.

本文提出了一项实验研究，旨在从根本上了解控制嵌段共聚物晶粒和缺陷结构的因素。嵌段共聚物是一类表现出从无序相到具有液晶对称性的有序纳米结构的对称性破坏相变的一般材料。典型的例子包括片层和排列在六边形晶格上的圆柱体。然而，这些材料中的相干顺序被限制在有限的区域或颗粒中，并伴有缺陷。本文提出了三个问题：晶粒形核、缺陷动力学和晶粒对宏观变形的微观响应。我们将用来获得晶粒结构的主要工具是去偏振光散射。光学性质与嵌段共聚物晶粒结构（尺寸、形状和晶粒间相关性）之间的关系是在我们的实验室建立的。光学实验将增加电子显微镜、中子散射和流变学。初步研究所需的样品已经通过高真空阴离子聚合合成；必要时将合成额外的样品。该基金资助的学生将学习聚合物合成、光谱学和色谱法表征聚合物、光散射、x射线和中子以及凝聚态物理等领域的知识。这种跨学科的培训在政府和工业研究实验室中变得越来越重要。