PECASE: Photopolymerization Kinetics and Consequent Nanostructure of Lyotropic Liquid Crystalline Systems

PECASE：光聚合动力学和溶致液晶体系的纳米结构

• 批准号: 0328231
• 负责人: Allan Guymon
• 金额: --
• 依托单位: University of Iowa
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-02-10 至 2008-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0328231&HistoricalAwards=false
• 关键词: PECASE; Photopolymerization; Kinetics; Consequent; Nanostructure

ABSTRACT0093911University of Southern MississippiAllan GuymonThe unique ordering presented by polymerizable lyotropic liquid crystalline (LLC) systems provides a wide variety of structures for a number of potentially important applications. The major obstacle in using polymerized LLC materials, however, is the ability to remain and control this structure throughout the polymerization. Typically, thermodynamically driven phase separation occurs during polymerization, leaving little or no liquid crystalline order. The theme of the research planned by the PI is to use the photopolymerization kinetics as a nanoscopic probe to predict and control the nanostructure of LLC systems. Two fundamental and complementary questions will be addressed using a combination of polymerization of LLC monomers and LLC templated polymerizations. First, what role do order and the degree of order have in influencing the polymerization behavior? The photopolymerization of materials spanning the gamut of LLC phases will be monitored to understand changes that occur during polymerization. Factors that may influence phase behavior and structure control including temperature, LLC phase structure and stability, composition, polymerization time scale, and mobility will be examined. Second, what influence does the polymerization have on structural evolution and the ability to control this structure? Factors influencing phase behavior, phase separation, polymer structure and anisotropy will be examined extensively before, during and after polymerization. Results for both questions will be related forming a complete model of the factors, both kinetic and thermodynamic, governing the ultimate polymer structure. Tangible outcomes of this research are (1) development of a complete understanding of the polymerization and the mechanisms governing ultimate polymer structure and (2) establishment of the principles and methods for the molecular level design of LLC systems with controllable and adjustable nanostructure designed for particular applications.A prevailing theme in this PECASE project will be student education. Extensive involvement of undergraduate and graduate researchers in a discovery learning environment will be emphasized. As a means to attract the best and brightest students to polymer science and engineering, a polymer module for high school chemistry is a primary element of the educational component. In collaboration with Petal High School, a three-week module will be developed that presents the fundamentals, applications, and research opportunities in the field of polymer science. Lecture, demonstration, laboratory, and testing materials will be correlated to emphasize the importance of polymers in everyday life. Virtual labs, web-based materials and hands-on experiments will be incorporated. The curriculum will involve extensive planning and involvement from the school district, the university, and local industry. After successful implementation, the module will be brought to the Hattiesburg and Oak Grove school districts. From these experiences a two-day instruction course will be developed for high school chemistry teachers throughout the state. Special focus will be placed on involvement of districts with high percentages of underrepresented groups in science and engineering. The module will also be modified appropriately for introductory chemistry courses at both junior colleges and universities.

可聚合溶致液晶（LLC）体系所呈现的独特有序性为许多潜在的重要应用提供了多种结构。 然而，使用聚合LLC材料的主要障碍是在整个聚合过程中保持和控制这种结构的能力。 通常，在聚合期间发生结晶驱动的相分离，留下很少或没有液晶有序。 PI计划的研究主题是使用光聚合动力学作为纳米探针来预测和控制LLC系统的纳米结构。 两个基本的和互补的问题将使用LLC单体的聚合和LLC模板聚合的组合来解决。 首先，有序度和有序度在影响聚合行为中起什么作用？ 将监测跨越LLC相范围的材料的光聚合，以了解聚合过程中发生的变化。 可能影响相行为和结构控制的因素，包括温度，LLC相结构和稳定性，组合物，聚合时间尺度和流动性将被检查。 第二，聚合对结构演化和控制这种结构的能力有什么影响？ 影响相行为、相分离、聚合物结构和各向异性的因素将在聚合之前、期间和之后进行广泛的研究。 这两个问题的结果将形成一个完整的模型的因素，动力学和热力学，支配最终的聚合物结构。 本研究的主要成果是：（1）对聚合反应和最终聚合物结构的控制机制有了完整的认识;（2）建立了具有可控和可调纳米结构的LLC体系的分子水平设计的原理和方法。 将强调本科生和研究生研究人员在发现学习环境中的广泛参与。 作为吸引最优秀和最聪明的学生学习聚合物科学和工程的一种手段，高中化学的聚合物模块是教育部分的主要元素。 与花瓣高中合作，将开发一个为期三周的模块，介绍聚合物科学领域的基础知识，应用和研究机会。 讲座，演示，实验室和测试材料将相互关联，以强调聚合物在日常生活中的重要性。 虚拟实验室，基于网络的材料和动手实验将被纳入。 该课程将涉及广泛的规划和学区，大学和当地行业的参与。 在成功实施后，该模块将被带到哈蒂斯堡和橡树格罗夫学区。 根据这些经验，将为全州的高中化学教师开发为期两天的教学课程。 将特别注重让科学和工程领域代表性不足群体比例高的地区参与。 还将对该单元进行适当修改，以适用于初级学院和大学的化学入门课程。