Structures and growth mechanisms of patterned polycrystals by polarimetric imaging

偏振成像图案化多晶的结构和生长机制

• 批准号: 0845526
• 负责人: Bart Kahr
• 金额: $ 58.79万
• 依托单位: New York University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-01 至 2013-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0845526&HistoricalAwards=false
• 关键词: Structures; growth; mechanisms; patterned; polycrystals

The Organic and Macromolecular Chemistry Program in the Chemistry Division at the National Science Foundation supports Professor Bart Kahr at New York University, who will provide an understanding of the structures of polycrystalline formations, which have characteristic lenghtscales of 10 micrometers. The investigator addresses the mechanisms leading to such patterning, the optical properties of the meso-structures, and potential applications in technology and in other scientific fields. Professor Kahr proposes to attack a very complex subject, namely, to use to Mueller matrix imaging polarimetry (and related techniques) to determine the structures and growth mechanisms of banded spherulites of small organic compounds. These polycrystalline systems have been the subject of earlier studies by researchers who proposed a simple, single, growth mechanism that involved the twisting of radii. This proposal attempts to understand growth mechanisms in these self-assembling systems and in some cases reveal new phenomena. Preliminary results suggest that the twisting mechanism is not in fact the universal explanation of optical banding. Future work should lead to a much deeper understanding of the origins of the nonequilibrium pattern formation in these systems. Understanding and controlling the spontaneous formation of chiral mesoscale structures transcend fundamental questions of crystal growth, and may lead to applications from mirrors to waveguides, and in producing chiral thin films.The broader impact of the proposed investigations will be significant. The investigator is dedicated to chemical education starting at the kindergarten level. He has found intriguing evidence that crystallography was one of the topics covered in the curriculum of the first children?s day care facilities in Germany in the 19th century. Professor Kahr has written and translated books and articles on the history of chemistry and crystallography. He is in contact with the authors of major chemistry books to insure that his findings reach undergraduate chemistry students in a timely manner. Courses for teachers are planned and these are major components of the broader outreach plan. The investigator has a track record of working with underrepresented groups of students. Professor Kahr is planning on working with local schools to bring students to his lab to participate in research projects with the hope of developing college-bound scientists who would otherwise never enter the pipeline.

美国国家科学基金会化学部的有机和高分子化学项目支持纽约大学的Bart Kahr教授，他将提供对多晶地层结构的理解，其特征长度为10微米。研究者讨论了导致这种图案化的机制，介观结构的光学性质，以及在技术和其他科学领域的潜在应用。Kahr教授提出了一个非常复杂的课题，即使用Mueller矩阵成像旋光法（及相关技术）来确定小有机化合物的带状球晶的结构和生长机制。这些多晶系统是研究人员早期研究的主题，他们提出了一种简单，单一的生长机制，涉及半径的扭曲。该建议试图了解这些自组装系统中的生长机制，并在某些情况下揭示新的现象。初步结果表明，扭曲机制实际上并不是光学带的普遍解释。未来的工作应导致更深入地了解在这些系统中的非平衡模式形成的起源。理解和控制手性介观结构的自发形成超越了晶体生长的基本问题，并可能导致从反射镜到波导的应用，以及在制备手性薄膜中的应用。研究员致力于从幼儿园开始的化学教育。他发现了有趣的证据，证明晶体学是第一批儿童课程中的一个主题。19世纪世纪德国的日托设施。卡尔教授撰写并翻译了有关化学和结晶学历史的书籍和文章。他与主要化学书籍的作者保持联系，以确保他的研究结果及时到达本科化学学生。已计划为教师开设课程，这些课程是更广泛的外联计划的主要组成部分。调查员有与代表性不足的学生群体合作的记录。卡尔教授计划与当地学校合作，让学生到他的实验室参加研究项目，希望培养出那些永远不会进入管道的大学科学家。