Micro Coalescence Cell for Investigating Impurity Effects

How do bubbles form and behave in liquids and why is this so important for our environment and industry? This research project investigates so-called multiphase systems, mixtures of gas, liquid, and sometimes solid materials. Such systems are part of our everyday lives: when cooking, in clouds, in the ocean, or in sparkling mineral water. At the same time, they form the basis of many industrial processes such as wastewater treatment, chemical production, and pharmaceutical manufacturing. A key aspect of these systems is coalescence the merging of two bubbles into a larger one. This seemingly simple process has far-reaching effects: it determines the size and surface area of bubbles, which in turn control how effectively substances are exchanged between gas and liquid. Examples include the transfer of oxygen during wastewater purification or carbon dioxide during chemical reactions. Whether bubbles merge quickly or remain separate influences the flow, mass transfer, and energy efficiency of an entire process. In industrial applications, this can determine how effectively a reaction takes place. In nature, coalescence plays an equally vital role: it affects how quickly gases dissolve in seawater or escape back into the atmosphere processes that directly influence the global carbon cycle and the climate. A deeper understanding of these mechanisms helps to control technical processes more precisely, save energy, and reduce environmental impact. More broadly, it also offers insights into how the oceans function as the lungs of the Earth and how bubbles affect the exchange of greenhouse gases. To achieve this, the project develops a novel method for deliberately triggering and precisely measuring bubble coalescence. In a specially designed microchannel, bubbles are brought together under controlled conditions and observed with high- speed cameras. Using artificial intelligence, the image data are automatically analyzed, revealing even the smallest movements and shape changes that would otherwise remain invisible. This provides an unprecedented view of bubble behavior on the microscale. The collected data will be compiled into an open-access database, systematically recording the properties of various liquids. These findings form the basis for models that enable better design and scale-up of industrial processes from laboratory experiments to large-scale applications. At the same time, an open testing unit is being developed that can be used worldwide to facilitate collaboration and data comparison across research groups. The project bridges traditional laboratory work and modern data analysis: chemical and process engineering meet computer science. Precise experiments provide data, while machine learning uncovers hidden patterns. The result is a powerful tool that links innovation and climate protection paving the way for more sustainable technologies.