UNS: Employing hydrodynamic lift and particle trajectory ratcheting to achieve sieve-free separations based on size and shape in cross-flow filtration

1505795（Koch）拟议研究的重点是研究悬浮液交叉流过滤过程中发生的颗粒传输现象。除了对这些现象的基本理解的发展，目标是帮助开发所谓的无筛过滤系统。虽然所提出的工作是高度基础性的，工程应用是其动机。这是一个建议，进行相结合的理论/数值/实验研究的颗粒分离在横流。本研究的动机是改进交叉流过滤的实践-一种从流体和较小尺寸颗粒中分离颗粒（包括细胞或大分子）的高通量方法。 在常规操作中，分离是通过筛过具有小孔径的膜来完成的。PI认为（专家组也同意这一点值得探讨），使用颗粒流体动力学输送过程而不是膜排斥完成分离的操作具有减少膜污染和提高分离选择性的优点。由于在错流过滤中可获得的高剪切速率，惯性提升可使颗粒远离粗糙的非筛分膜。此外，一种新的无筛分离机制的基础上棘轮的颗粒轨迹在粗糙的表面的膜由于排除体积的相互作用的颗粒与膜将被调查。我们的目标是开发一个基于升力的交叉流的预测模型，允许基于形状和尺寸进行分离，并确定最大过滤通量和颗粒浓度，在该浓度下可以保留颗粒。这种机制可以导致太小而不能基于流体动力学提升分离的纳米颗粒或蛋白质的无筛分离。开发的模型将进行测试和无筛过滤的可靠性证明了通过实验测量的微米和纳米颗粒的分离以及控制的尺寸和形状在库埃特细胞过滤器。除了研究生教育外，还制定了向K-12学生伸出援手的计划，并在当地儿童博物馆和伊萨卡科学中心的活动中进行实验示范。

1505795(Koch)The focus of the proposed research is to study particle transport phenomena that occur during cross-flow filtration of suspensions. In addition to development of fundamental understanding of these phenomena, the objective is to aid the development of a so-called sieve-free filtration system. While the proposed work is highly fundamental, engineering applications are its motivation.This is a proposal to conduct a combined theoretical/numerical/experimental study of particle separation in crossflow. The motivation for this study is to improve practices in cross-flow filtration - a high throughput method of separating particles (including cells or macromolecules) from a fluid and from smaller sized particles. In conventional operation, the separation is accomplished by sieving through a membrane with a small pore size. The PI argues, and the panel agreed that this is worth exploring, that an operation in which the separation is accomplished using particulate hydrodynamic transport processes rather than membrane exclusion would have the advantages of decreasing membrane fouling and improving the selectivity of the separation. Because of the high shear rates accessible in cross-flow filtration, inertial lift can keep the particles away from the coarse non-sieving membrane. In addition, a new sieve-free separation mechanism based on the ratcheting of particle trajectories at the rough surface of the membrane due to excluded volume interactions of the particle with the membrane will be investigated. The goal is to develop a predictive model for lift-based cross-flow, allowing separation based on shape as well as size and identifying the maximum filtration flux and particle concentration at which particles can be retained. This mechanism can lead to sieve-free separations of nanoparticles or proteins which are too small to separate based on hydrodynamic lift. The models developed will be tested and the reliability of sieve-free filtration demonstrated by experimental measurements of separation of micro- and nano-particles of well controlled size and shape in a Couette cell filter. In addition to graduate education, plans to reach out to K-12 students and by an experimental demonstration to be used in activities at the local children's museum and the Ithaca Science Center are laid out.