Study of Particle Deposition and using Total Internal Reflection Microscopy

约翰·瓦尔兹摘要 研究胶体颗粒在固体表面沉积的传统方法是旋转圆盘实验和填充床实验。 当这些实验的结果与当前的理论模型进行比较时，经常观察到实质性的差异。 这种不一致的可能原因包括大量影响沉积速率的因素，以及这些实验中测量的速率代表许多颗粒和捕获位点的平均值。 这项研究提出了一种新的方法来研究粒子捕获通过使用两种新的光学技术：全内反射显微镜（TIRM）和辐射压力（或“光镊”）。 这些技术将允许在仔细控制的条件下测量固体表面上固定位置处单个颗粒的沉积速率。 目标是测量特定因素对颗粒捕获率的影响。 实验装置将被设计成使得离子强度、粘度、流体速度、颗粒尺寸和净颗粒重量可以被调节。 这些测量的结果将提供新的见解，在各种各样的工业过程中应用的沉积机制。

John Walz Abstract The traditional methods for studying deposition of colloidal particles onto solid surfaces are the rotating disc and packed bed experiments. When the results of such experiments are compared with current theoretical models, substantial discrepancy is frequently observed. Possible reasons for this disagreement include the large number of factors affecting the deposition rate and the fact that the measured rate in these experiments represents an average over many particles and capture sites. This research proposes a new approach to studying particle capture through the use of two novel optical techniques: total internal reflection microscopy (TIRM) and radiation pressure (or "optical tweezers"). These techniques will allow measurement of the deposition rate of a single particle at a fixed position on a solid surface to be taken under carefully controlled conditions. The objective will be to measure the effect of specific factors on the rate of particle capture. The experimental apparatus will be designed such that ionic strength, viscosity, fluid velocity, particle size, and net particle weight can be adjusted. The results of these measurements will provide new insight into deposition mechanisms applied in a large variety of industrial processes.