PECASE: Direct Measurement and Manipulation of Colloidal Interactions and Dynamics in Template Directed Photonic Crystal Assembly

摘要CTS-0346473M。CAREER：模板导向光子晶体组装中胶体相互作用和动力学的直接测量和操纵本提案涉及在界面模板上和外场存在的情况下对单个光子胶体晶体组装所涉及的胶体相互作用的测量和操纵。其目的是了解胶体力和流体动力相互作用与界面“自组装”和“驱动组装”过程中热力学结构和动力学路径形成的基本机制。这项工作的一个中心任务是结合全内反射、视频和共焦扫描激光显微镜技术来测量日益复杂的界面胶体系统中的颗粒-颗粒、颗粒-模板和颗粒-场相互作用，范围从单个颗粒到集中的三维分散。由于能够直接测量多体界面相互作用，与胶体晶体在模板衬底上自组装相关的弱吸引力将受到微调温度和特定离子相关的聚合物分散力的控制。为了避免形成不可逆的凝胶和受阻的玻璃结构，将使用交流电泳驱动的中间亚稳态晶体结构的组装来操纵光子晶体组装过程中的动力学路线。蒙特卡罗和斯托克斯动力学模拟将用于了解如何形成最优的平衡粒子构型，以及如何控制动力学以避免动力学陷阱。每个拟议的实验都提供了关于如何操纵胶体系统来组装大型单界面光子晶体的补充信息，这对寻求在衬底上组装任意纳米和微结构材料和器件的任何技术都具有广泛的意义。拟议的职业生涯计划的智力优势基于其在胶体长度、时间和能量尺度上操纵有序界面结构的基本意义，这些结构本质上是分子和宏观系统的中间层，因此对纳米科学和技术至关重要。在这个建议中的教育计划涉及将我研究小组的显微/模拟实验中的图像、视频和动画广泛地结合到面向本科生和研究生的胶体复杂流体/纳米技术课程中。其目的是使用可视化和多媒体工具来帮助不同学习风格的学生快速形成必要的心理图画，以保持对胶体科学的物理直观理解。由于我在研究中使用光学显微镜来探索基本的胶体现象，直接将图像和视频融入课堂讲课对我来说是一种自然的方式，我会热情地教给学生们使用“真实”的多尺度研究实例，这也与化学工程课程改革的倡议是一致的。作为开发可视化工具的一部分，德克萨斯农工大学沉浸式可视化中心的虚拟现实演示将作为一门特别的课堂讲座提供，也将作为一种经常使用的推广工具，通过现有的NSF赞助的校园项目向代表不足的群体、K-12学生和教师推广。为了评估课堂多媒体工具的有效性和优化实施，学校精神病学/ED的合作者。技术部。在德克萨斯农工学院，我将帮助评估我基于可视化的讲座的认知和教学方面，并在教育期刊和国家会议上传播研究结果。拟议的职业生涯计划的更广泛影响与直接使用我在课程和外联计划中研究的显微镜和模拟视频有关，以在未来工程师的培训和提高普通公众的科学素养方面提高学习的深度、速度、留存率和乐趣。

AbstractCTS-0346473M. Bevan, Texas A&M UniversityCAREER: Direct Measurement and Manipulation of Colloidal Interactions andDynamics in Template Directed Photonic Crystal AssemblyThis proposal is concerned with measurement and manipulation of colloidal interactions involved in the assembly of single photonic colloidal crystals on interfacial templates and in the presence of external fields. The objective is to understand fundamental mechanisms linking colloidal forces and hydrodynamic interactions to formation of thermodynamic structures and kinetic pathways in interfacial "self-assembly" and "driven assembly" processes. A central task in this work is to combine total internal reflection, video, and confocal scanning laser microscopy techniques to measure particle-particle, particle-template, and particle-field interactions in increasingly complex interfacial colloidal systems ranging from single particles to concentrated three dimensional dispersions. With the ability to directly measure many-body interfacial interactions, weak attractive forces relevant to colloidal crystal self-assembly on templated substrates will be controlled by finely tuning temperature and specific ion dependent polymeric dispersion forces. To avoid formation of irreversible gel and arrested glass structures, AC electrophoretic driven-assembly of intermediate metastable crystalline structures will be used to manipulate the kinetic route in photonic crystal assembly processes. Monte Carlo and Stokesian dynamics simulations will be used to understand how to form optimal equilibrium particle configurations and how to control dynamics to avoid kinetic traps. Each proposed experiment provides complementary information on how to manipulate colloid systems to assemble large single interfacial photonic crystals, which has broad significance for any technology that seeks to assemble arbitrary nano- and micro- structured materials and devices on substrates. The intellectual merit of the proposed career plan is based on its fundamental significance to manipulating ordered interfacial structures on colloidal length, time, and energy scales, which are inherently intermediate to molecular and macroscopic systems and therefore of utmost importance to nano- science and technology.The educational plan in this proposal involves extensively incorporating image, video, and animations from microscopy/simulation experiments in my research group into a colloidal complex fluids/nanotechnology course for both undergrad and grad students. The objective is to use visualization and multimedia tools to help students with different learning styles quickly develop mental pictures necessary to retain a physically intuitive understanding of colloid science. Because I employ optical microscopy to explore fundamental colloidal phenomena in my research, directly incorporating images and videos into class lectures is a natural way for me to passionately teach students using "real" multiscale research examples, which is also consistent with chemical engineering curriculum reform initiatives. As part of developing visualization tools, a virtual reality presentation in the Immersive Visualization Center at Texas A&M will be delivered as a special class lecture, and will also be used as a frequent outreach tool to underrepresented groups, k-12 students, and teachers through existing NSF sponsored campus programs. To assess the effectiveness and optimize the implementation of classroom multimedia tools, collaborators in School Psych./Ed. Tech. at Texas A&M will help to evaluate cognitive and pedagogical aspects of my visualization based lectures, with findings disseminated in education journals and at national conferences. The broader impact of the proposed career plan is related to the direct use of microscopy and simulation visuals from my research in courses and outreach programs to improve the depth, rate, retention, and enjoyment of learning in the training of future engineers and in improving scientific literacy of the general public.