Experimental Investigation of Oil–Water Emulsion Droplets Impact on Membrane Surfaces under High Pressures
- Institute
- Lehrstuhl für Thermodynamik (TUM-ED)
- Type
- Semester Thesis Master's Thesis
- Content
- Description
Background
Membrane-based separation is an energy-efficient and widely applicable approach for the treatment of oil–water emulsions. The separation performance is strongly influenced by membrane wettability, surface morphology, pore structure, and the dynamic interaction between emulsion droplets and the membrane surface.
Our previous experiments revealed an important pressure-dependent phenomenon during droplet impact: elevated ambient pressure significantly enhances the interfacial gas-film effect between an impacting droplet and the underlying liquid or solid interface. The thicker and longer-lived gas layer delays direct liquid–surface contact and can consequently suppress coalescence, wetting, and penetration. For membrane-based oil–water separation, such a pressure-induced gas cushioning effect may substantially reduce separation efficiency. This effect is particularly relevant to oil–water separation processes operating under pressurized environments, where membrane properties optimized under atmospheric conditions may no longer provide optimal performance.
The present work therefore aims to develop modified or newly fabricated membrane surfaces capable of promoting efficient droplet–membrane contact and oil–water separation under elevated ambient pressure. By systematically tailoring membrane wettability, surface morphology, and/or pore structure, the relationship between membrane properties, interfacial gas-film behavior, and separation performance will be investigated.
Methods
The experimental high-pressure droplet-impact platform is already available but requires further adaptation for membrane-based separation experiments.
The main work will include:
* Selection, fabrication, and/or surface modification of hydrophilic and hydrophobic membranes.
* Characterization of membrane properties, including wettability, surface morphology, and pore characteristics.
* Investigation of droplet spreading, rebound, adhesion, penetration, coalescence, and separation behavior.
* Characterization of the influence of membrane properties on the formation, drainage, and rupture of the interfacial gas film.
* Evaluation of oil–water separation performance under different ambient pressures.
* Optimization of membrane surface properties to mitigate the adverse effects of high-pressure gas cushioning.
Previous Work
Previous experiments have demonstrated a pronounced pressure effect on the interfacial gas layer during droplet impact. Under elevated ambient pressure, the gas film separating the impacting droplet from the underlying interface becomes significantly more pronounced and can sustain non-contact conditions for substantially longer periods. Further details could be referred to https://doi.org/10.1002/smtd.202500913.
These observations provide the motivation for the present work: rather than treating ambient gas pressure as a secondary operating parameter, the project considers the gas film as an additional interfacial resistance that can potentially be controlled through membrane engineering.
- Requirements
* MSc student in mechanical engineering, chemical engineering, materials science, chemistry, process engineering, or a related field.
* Strong interest in experimental research, membrane technology, surface engineering, and multiphase flow.
* Experience with membrane fabrication/modification, surface characterization, high-speed imaging, or image processing would be advantageous.
* Basic knowledge of Python or MATLAB would be beneficial.
- Possible start
- immediately
- Contact
-
M.Sc. Yan Yan
Room: 5507.EG.729
Phone: +49 89 289 16193
y.yantum.de