Collaborative Proposal: Separation of Nanoparticles Using Patterned Surfaces: Multiscale Transport and Experiment

美国国家科学基金会-化学和运输系统分部-颗粒和多相过程项目（1415）提案号：0731109首席研究员：Koplik， joel隶属关系：纽约市立大学提案标题：合作研究：利用梯度表面分离纳米颗粒；多尺度模拟和实验在流体装置中引导颗粒到所需位置同时允许它们保持悬浮在溶液中的能力是具有挑战性的，因为微粒子和纳米粒子经历布朗运动。我们已经构思了一种技术，利用布朗运动本身，通过控制装置边界表面的能量景观，在空间上聚焦粒子。我们利用这种粒子聚焦技术来创建分离单元，用于悬浮胶体的连续分馏。设想的装置提供了一种新的方法来分离悬浮粒子，该方法基于在装置边界壁上产生亲和梯度的物种的差异相互作用。总体结果是混合物的矢量分离，其中不同的物种向不同的方向移动，从而允许与一维系统相比具有更高的分离功率和峰值容量的连续操作。该策略是将最先进的微制造技术与多尺度建模和仿真相结合，设计和实验测试这些微纳米流体分离装置。智力优势：对粒子表面相互作用的深刻理解对于所提出的分离装置的成功设计和优化至关重要。与开发和改进制造纳米级材料或器件所需的实验技术的重大活动和进步相比，理解纳米尺度上输运现象的框架还不太发达，特别是在具有明显几何限制的情况下，如这里感兴趣的情况，其中通道尺寸与悬浮颗粒的大小相当。因此，我们提出了一项合作努力，将关键实验与多尺度建模和模拟相结合，所有这些都旨在了解具有几何约束的流动条件下颗粒表面相互作用的主要方面。更广泛的影响。科学方面：粒子的布朗漂移阻碍了人们想要在流体装置的特定位置处理特定粒子的应用。本研究中研究的聚焦方案可用于克服这些复杂性，并可广泛应用于芯片实验室设备中。在这种情况下，考虑到流体装置中的粒子操纵领域和表面性质主动控制领域的高活性，这项工作的潜在扩展是广泛的。更广泛的影响。教育和推广方面：我们项目中粒子表面相互作用产生的基本问题，以及利用分子现象进行技术应用的潜在影响，将被纳入为本科生和研究生设计的“分子模拟”和“纳米材料界面现象”课程的模块，这些课程目前是参与机构的IGERT项目的一部分。这些模块将为学生提供一个清晰的例子，说明为了理解纳米科学中的复杂问题，并能够解决纳米技术中的挑战性问题，需要多学科团队。此外，目前的项目将为本科生和高中生提供实践经验，这些学生将从两所机构的不同推广和教育项目中汲取经验。学生们将成为一个多元化的研究团队的一部分，因此，将为生物分子和化学工程日益跨学科的领域做好更好的准备。学生们将在会议和研讨会上展示他们的研究成果，并负责维护一个研究网页，以便及时向公众展示研究成果。

National Science Foundation - Division of Chemical &Transport Systems Particulate & Multiphase Processes Program (1415)Proposal Number: 0731109Principal Investigators: Koplik, JoelAffiliation: CUNY City CollegeProposal Title: Collaborative Research: Separation of nanoparticles using gradient surfaces: multiscale simulations and experimentsThe ability to guide particles to a desired location in a fluidic device while allowing them to remain suspended in solution is challenging since micro- and nano-particles undergo Brownian motion. We have conceived a technique that exploits Brownian motion itself to focus particles spatially by controlling the energy landscape on the bounding surfaces of a device. We exploit this particle focusing technique to create separation units for the continuous fractionation of suspended colloids. The conceived devices provide a novel approach to the separation of suspended particles based on the differential interaction of the species with affinity gradients created on the bounding walls of the device. The overall result is the vector separation of the mixture, in which different species move in different directions, thus allowing for continuous operation with higher separation power and peak capacity compared to one-dimensional systems. The strategy is to combine state-of-the-art microfabrication, with multiscale modeling and simulation, to design and experimentally test these micro- and nanofluidic separation devices.Intellectual merit: A deep understanding of particle-surface interactions is crucial to a successful design and optimization of the proposed separation devices. In contrast to the significant activity and advances in developing and refining experimental techniques needed to fabricate nanoscale materials or devices, the framework for understanding transport phenomena at nanometer scales is less developed, particularly in cases with significant geometric confinement as in the case of interest here, in which the channel dimension is comparable to the size of the suspended particles. Therefore, we propose a collaborative effort, combining critical experiments with multiscale modeling and simulations, all aimed at understanding the dominant aspects of particle-surface interactions under flow conditions with geometric confinement.Broader Impact. Scientific aspects: Brownian excursions of particles hamper applications in which one wants to address specific particles at specific positions within a fluidic device. The focusing scheme investigated in this work could be used to overcome those complications, and could be widely exploited in lab-on-a-chip devices. In this context, the potential extensions of this work are broad, given the high activity in the field of particle manipulation in fluidic devices, and in the field of active control of surface properties.Broader Impact. Education and Outreach aspects: The fundamental issues resulting from particle-surface interactions in our project, as well as the potential impact of harnessing molecular phenomena for technological applications, will be incorporated in modules designed for undergraduate and graduate level courses in "Molecular simulations" and "Interfacial Phenomena in Nanomaterials", which are currently part of IGERT programs in the participating institutions. These modules will provide the students with a clear example of the need for multidisciplinary teams in order to understand complex problems in nanoscale science and to be able to address challenging issues in nanotechnology. In addition, the present project will provide hands-on experience to undergraduate and high school students drawn from the different outreach and educational programs available at both institutions. The students will be part of a diverse team of researchers and, as a result, will be better prepared for the increasingly interdisciplinary field of biomolecular and chemical engineering. The students will present their results in conferences and workshops and will be responsible for maintaining a research webpage that will present the results in a timely manner and for the general public.