Final Thesis

Impact of microgels on mass transfer considering interfacial phenomena

Key Info

Basic Information

Unit:
Fluid Process Engineering
Type:
Masterthesis
Focus/Key Topic:
experimental
Date:
18.06.2019

Contact

Microgels are polymer particles that have a high application potential in process engineering due to their switchable properties. The deformable polymer particles are particularly characterized by switchable structural changes. These cause a change in the properties, especially at liquid-liquid interfaces. A promising field of application is the liquid/liquid extraction, where the microgels stabilize the rising droplets and thus guarantee a uniform droplet size distribution in the column. Since the stabilization is based on the deposition of the microgels at the interface, the influence of the stabilization on the mass transport will be investigated in this paper. The mass transport at the single droplet is a complex interplay of different phenomena and is determined by the flow conditions in the droplet. These, in turn, are determined by interfacial mobility and concentration-induced interfacial instabilities, which can be significantly influenced by the deposition of microgels at the interface. The aim of this thesis is the investigation of the mass transport through microgel stabilized interfaces considering the microgel properties and their influence on interfacial phenomena. For this purpose, concentration-induced interfacial instabilities and interfacial mobility are to be considered. At first, the influence of microgels on the mass transport in single droplets will be experimentally investigated. The influence of different microgels, which differ in size and degree of cross-linking, as well as the interfacial loading with microgels will be investigated. In addition, different droplet diameters and residence times will be investigated. In order to minimize the experimental effort, a new measuring method has been developed which significantly reduces the number of droplets to be investigated per experiment. The results will also be compared with theoretical models. The basis for this is a single drop model developed at the chair, which is to be adapted for the microgel stabilized drops. Subsequently, the model will be used to describe the contribution of instabilities and mobility, including the experimental results. The results of the work will be discussed and documented.