Rotation Diffusion of MOON Particles

[00:853737 . granicks]这个建议关注的是一个尚未开发的课题，即胶体粒子旋转的速度有多快。Kopelman及其同事最近开发的光学各向异性月球粒子（调制光学纳米粒子）为基于这一概念突破的许多有趣的工作奠定了基础。具体来说：(a)任务1：浓缩胶体悬浮液的平移-旋转解耦。布朗运动，表现为旋转，将在单粒子水平上进行研究。(b)任务2：以月球粒子为积木的新的和有趣的各向异性胶体结构将显示在这里研究的动态重排；(c)任务3：磁场将用于驱动旋转，因此不仅可以进行线性和非线性粘弹性研究，而且在超过屈服强度时，还可以进行颗粒-颗粒摩擦研究。这为在单个胶体颗粒水平上研究微流变学/纳米流变学打开了大门。粒子跟踪对胶体场产生了巨大的影响，但几乎只停留在平移运动上。这个提议认为，现在是时候对粒子旋转做同样的研究了。智力上的优点是双重的。首先，这将发展对胶体动力学的新理解，这是许多科学和技术应用的基础，包括油漆、浆料、粉末、原料提取、复合材料和纳米复合材料的机械行为，以及这些材料在催化和能量收集等其他领域的应用。这项研究将产生新的实验工具来量化粒子动力学，这是传统方法无法表征的。其次，所开发的方法可能会在其他研究小组中得到普遍应用，因为在制定方案并证明其价值之后，它们也应该找到更广泛的用途。这项工作将引入多相流领域，具有单粒子灵敏度的成像方法在该领域具有特殊的前景。这将通过开发以前未在该学科中使用的新技术来改善多相流领域的研究基础设施。更广泛的影响是整合研究和教育。由于这些方法是多相流领域的新方法，它们的使用将完成学科之间的重大智力转移。此外，研究生将与其他来自化学、化学工程、物理和材料科学的学生组成跨学科研究小组。将努力从代表性不足的群体中招收研究生。将要求REU补充，以便本科生可以参与。这个实验室有一个很好的记录，让女性和西班牙裔本科生研究人员从大一开始，一直持续到获得本科学位，并根据这项研究撰写荣誉论文。该提案详细讨论了将由该提案以及该实验室启用的更广泛的影响活动。我在这方面的工作记录。

0853737GranickThis proposal focuses on an undeveloped subject, how fast colloidal particles rotate. The recent development of optically anisotropic MOON particles (modulated optical nanoparticles) by Kopelman and coworkers sets the stage for much interesting work predicated on this conceptual breakthrough. Specifically: (a) Task 1: Translation-rotation decoupling in concentrated colloidal suspensions. Brownian motion, manifested as rotation, will be studied at the single-particle level.; (b) Task 2: New and interesting anisotropic colloidal structures with MOON particles as building blocks will show dynamical rearrangements proposed to study here; (c) Task 3: Magnetic fields will be used to drive rotation, thus enabling not only linear and nonlinear viscoelastic studies, but also, when a yield strength is exceeded, studies of particle-particle friction. This opens the door to study microrheology/nanorheology at the level of individual colloidal particles. Particle tracking has had a huge impact on the colloid field, yet has dwelt nearly exclusively on translational motion. This proposal argues that the time is right to seek to do the same concerning particle rotation.The intellectual merit is twofold. First, this will develop new understanding of colloidal dynamics, which is fundamental in many scientific and technical applications, including paints, slurries, powders, raw material extraction, the mechanical behavior of composite and nanocomposite materials -- as well as applications of these materials in other fields such as catalysis and energy harvesting. This research will result in new experimental tools to quantify particle dynamics that is impossible to characterize by conventional methods. Second, the methods developed may find general application in other research groups, as they should also find wider utility after protocols have been developed and their value has been demonstrated. This work will import, into the field of multiphase flow, imaging methods with single-particle sensitivity that hold exceptional promise for this field. This will improve research infrastructure in the multiphase flow field by developing new techniques not previously used in this discipline.The broader impact is to integrate research and education. As these methods are new to the field of multiphase flow, their use will accomplish a significant intellectual transfer between disciplines. Furthermore, the graduate students will be part of an interdisciplinary research group with other students from chemistry, chemical engineering, physics, and materials science. Efforts will be made to recruit graduate students from underrepresented groups. An REU supplement will be requested so that undergraduates can be involved. This laboratory has an excellent track record of involving women and Hispanic undergraduate researchers starting in their freshman year, continuing until receiving their undergraduate degree, and writing honors theses based on this research. This proposal discusses at length the broader impact activities that will be enabled by this proposal, as well as this laboratory?s track record in this area.