Master of Engineering Science
Mechanical and Materials Engineering
Current membrane separation processes are limited in high production and high purity settings due to a trade-off between selectivity and permeance. Methods of creating nanoscale geometries in 2D materials are emerging and present an opportunity for fast, size selective mass transport that can be tailored to a wide array of applications. This thesis develops a method for quantifying flow through small pores in plane walls based on the behaviour of a solute dispersed in a downstream reservoir. This method is validated for a range of micropore diameters, for which flow rates can be calculated with confidence, and is shown to provide accurate results up to a Reynolds number of 17. From an approximate control volume analysis, the method is shown to apply for both single pores and arrays of pores, making it a suitable candidate for future studies measuring flow rates through microscopic areas of nanoporous atomically thin membranes.
Summary for Lay Audience
Membrane separation devices are used in a wide array of applications, most notably in water desalination/purification, carbon capture, fuel cells and drug delivery. By utilizing materials that permit selective transport, one is able to separate substances based on size, chemical composition or charge. An ideal material would allow fast, unobstructed flow of desirable species and completely reject the undesired. Current devices do not have this capability and have a trade-off between flow rate and undesired species rejection. Emergence of one atom thick materials that are partially permeable, present the opportunity to realize the concept of an ideal membrane. In order to develop devices using these materials that are able to carry out the desired separation processes, an understanding of fluid flow behaviour and transport properties through various materials must be established. The flows emerging from these pores are so small that they are not detectable by conventional means. The purpose of this thesis is to develop a method for quantifying these small flows emerging from individual pores. Although jets emerging from the pore itself cannot be measured, the movement of the fluid in a downstream reservoir caused by the jet can be quantified and related to the jet flow. The behaviour of a fluorescent dye downstream of the pore is used to extract the volume flow rate through the pore itself. The method created in this paper can be used to analyze flows through nanoscale geometries, providing a basis for future separation device designs.
Edwards, Matia Peter, "Quantification of Flows Emerging From Small Pores in Plane Walls" (2022). Electronic Thesis and Dissertation Repository. 9098.
Available for download on Wednesday, May 31, 2023